ALBERT

Notes: Ring-opening copolymerization studies were made on the systems cyclopentene (CPE)/ norbornene (NBE), cyclooctene (COE)/ norbornene, 1,5-cyclooctadiene (COD)/norbornene, cyclopentene/cycloheptene (CHP), and cyclopentene/ 1,5-cyclooctadiene using olefin metathesis catalysts.13C NMR spectra of the copolymers permit direct determination of the reactivity ratios in most cases, as well as the proportion of cis double bonds in each type of dyad. For CPE/NBE, COD/NBE and CPE/CHP the reactivity ratios vary widely with the catalyst system and sometimes with the catalyst/cocatalyst ratio and method of mixing. There is no correlation between composition of the copolymer and cis content. The copolymers show either a random or blocky distribution of monomeric units. The results are discussed in terms of a mechanism in which the metal carbenes formed in the propagation processes are initially coordinated to the polymer chain and can add further monomeric units stereospecifically while in this form. These propagation processes compete with a relaxation process leading to a metal carbene in which the polymer chain is no longer coordinated at the vacant site and which adds monomer in a less stereospecific fashion.

Notes: With the aid of D-glyceric acid as a template, an amino- and a boronic acid group, respectively, were introduced in a defined steric arrangement into polymers. For this, the monomer D-N-(4-vinylphenyl)carbamoylethylenedioxy(4-vinylphenyl)borane (1) was copolymerized into macroporous polymers under various conditions. The template D-glyceric acid was split off from the polymer with 20% HCl in methanol. The specificity of the polymers obtained with one amino- and one boronic acid group, respectively, per cavity was derived from their ability to resolve racemic glyceric acid. Racemic resolution was also observed on equilibration of the polymers with D,L-methyl glycerate and D,L-glyceraldehyde.

Notes: Sulfomethylated resins are prepared by polymer analogous reactions, starting from macroporous poly(styrene-co-divinylbenzene) matrices. Different reaction paths are discussed and used in the synthesis. Sulfomethylation can be achieved by reaction of a chloromethylated resin with dimethyl sulfide and sodium sulfonate or alternatively by oxidation of polymer-bound thiol groups. Both methods give high conversions as shown by IR spectra and titration of the sulfonic acid groups. Poly[1-(4-hydroxysulfomethylphenyl)ethylene] (3) is obtained by reaction of poly[1-(4-hydroxyphenyl)ethylene] (2) resin with formaldehyde/sodium sulfonate. The thermal stability, catalytic activity, and ion exchange equilibria of the sulfomethylated resin are investigated.

Notes: Radical copolymerizations of mono- and di-l-menthyl fumarate (1 and 2) with styrene (St) were carried out, and the copolymers were hydrolyzed with potassium hydroxide. The products show still optical activity even after the removal of the optically active side chain, because of an introduction of asymmetry into the main chain of the copolymer. The specific rotation per one of the diad sequences of hydrolyzed poly(1-co-St) was the same as that of hydrolyzed poly(2-co-St). The mechanism of asymmetric induction and the position of the new asymmetric center are discussed based on the measurements of UV spectra, optical rotation, and circular dichroism.

Notes: The synthesis of 6-vinylchrysene (1) starting from chrysene is described. The study of the polymerizability of 1 by conventional radical, cationic, and Ziegler-Natta procedures indicates the tendency of 1 of give head-to-tail polymeric products with a similar degree of polymerization independent of the catalytic system. Copolymers of 1 with optically active (-)-menthyl acrylate (2), (-)-menthyl methacrylate (3), and (S)-4-methyl-1-hexene (4), were also prepared. No apparent copolymerization of 1 with optically active alkyl vinyl ethers occurred by cationic initiation. Spectroscopic and chiroptical properties are presented to support the formation of copolymer macromolecules. Finally, the differential dichroic absorption measurements allow one to stress that in optically active vinylaromatic copolymers the extent of preferential asymmetry, induced by the dissymmetric field of units derived from the optically active nonaromatic comonomer, increases with increasing bulkiness and polarizability of the vinylaromatic comonomer.

Notes: The 13C NMR spectra of methylstyrenes and methoxystyrenes and their polymers prepared with radical initiators, a Ziegler catalyst, or a cationic catalyst were measured. The spectra of the polymers were assigned by the chemical shifts of the monomers and gated-decoupling method. The absorption of the aromatic C1 carbon of each polymer, which varied by the polymerization conditions, was assigned in terms of a pentad sequence assuming that the Bernoullian statistics holds for the polymerization of ring substituted styrenes. The stereoregularities calculated from C1 carbon absorptions were compared with those of polystyrenes obtained unter the same polymerization conditions. In the radical polymerization of ortho-derivatives, where the substituent locates near the polymer backbone, high syndiotactic polymers (Pr = 0,80 - 0,83) were prepared. The effect of the substituent in para-derivatives did not appear. On the other hand, random polymers were generally fromed by cationic polymerization regardless of the position and the type of the substituent.

Notes: The stereoregularity of the polymers of ortho-, meta-, and para-methylstyrenes prepared with various anionic catalysts was determined by means of 13C NMR spectroscopy. The substituent effect on the stereoregularity was discussed comparing with that of polystyrenes obtained under the same polymerization conditions. Syndiotactic-rich poly(methylstyrene)s were prepared with butyllithium in toluene and the syndiotacticity increased in the order of para-, meta-, and ortho-derivatives. Although the structure of the polymers prepared with sodium-naphthalene (Na-naph.) in THF did not change with the position of the substituent, in toluene, however, the methyl group at ortho-position influences the stereoregularity. The trend of the stereoregularity of the polymers produced by potassium-naphthalene was almost the same as that of poly(methylstyrene)s prepared by Na-naph. Nearly random polymers were obtained with the cesium ion as catalyst.

Notes: Polymerization of 1-(4-pyridyl)-1,3-butadiene (PyBu) initiated by 2,2′-azoisobutyronitrile (AIBN) or butyllithium (BuLi) was studied. Radical polymerization gave poly(PyBu) of low molecular weight, soluble in chloroform, tetrahydrofuran, or methanol. PyBu was polymerized by BuLi more rapidly than by AIBN, but the produced polyanion was not living. IR and 1H NMR spectra of poly(PyBu) indicate the presence of trans-1,4-and trans-3,4-units. The content of trans-1,4-units was found to be 75 mole-% (for radical polymerization) or 90 mole-% (for anionic polymerization). From radical copolymerization with styrene the following reactivity ratios resulted: r1 (PyBu) = 7,21, r2 (styrene) = 0,12; Q = 6, 1 and e = -0,42 (for PyBu). Reaction of PyBu with ethyl bromide in benzene at 30°C produced a polyelectrolyte, as observed in the case of 4-vinylpyridine.

Notes: The stereoregularity of poly(methoxystyrene)s was determined from the absorption of the aromatic C1 carbon assuming a first-order Markov statistics holds for the polymerization as well as polystyrenes. The stereoregularity of poly(p-methoxystyrene)s prepared by sodium, potassium, or rubidium cations as catalysts in THF hardly varied and syndiotactic-rich polymers were obtained, whereas a random polymer was formed with cesium-naphthalene. In the polymerization of p-methoxystyrene in toluene, syndiotactic-rich polymers were obtained with butyllithium and random polymers were prepared by sodium or potassium cations as catalysts. The stereoregularity of poly(o-methoxystyrene)s prepared by sodium or potassium cations in tetrahydrofuran changed with the polymerization temperatures, and highly syndiotactic polymers were formed at-78°C. The structure of poly(o-methoxystyrene)s obtained in toluene, markedly depended on the initiators; that is, with increasing the size of the ionic radius of the counterions, the isotacticity of the polymers decreased. The mechanism of the polymerization and the substituent effect of the stereoregularity are discussed.

Notes: α,ω-Dimethoxycarbonyl substituted polyenes were synthesized by co-metathesis between 1,5-cyclooctadiene (1) and dimethyl 3-hexenedioate (2) by use of the catalytic system WCl6/Sn(CH3)4. The ability of 2 for co-metathesis with 1 was proved by determination of the distribution of low molecular weight products in terms of reaction time and 2/1 mole ratio. For these studies, high values of 2/1 ratios (0,5-4) were chosen in order to obtain lowest molecular weight co-metathesis products (3b-3e). Metathesis involved preferentially the double bonds in the neighbourhood of the ester groups. At lower values of the 2/1 ratio (0,012-0,061) α,ω-difunctional prepolymers (3i) were synthesized.

Notes: The 1H NMR spectra of poly(methyl acrylate-d1) +CHD—CH(COOCH3)+n were measured in o-dichlorobenzene and CDCl3 in the temperature range between - 20 and 145°C. Trans and gauche coupling constant were determined from the temperature dependence of the geminal coupling constants, neglecting g' conformers. It was estimated that the proportion of trans conformer is 1,5 to 1,9 times that of the gauche conformer in this temperature range.

Notes: The intrinsic viscosities of a Gaussian chain with and without hydrodynamic interaction preaveraging and with the identification of the centre of gravity of the Gaussian coil with the chain center were calculated using Tsuda's theory. It appears that the value of the Flory constant is more affected by approximations used in the derivation of Tsuda's theory than by preaveraging of hydrodynamic interaction. Svetlov's theory was used in the calculation of the ratio of intrinsic flow birefringence to intrinsic viscosity. For unpreaveraged hydrodynamic interaction this quantity is lower by some 15-20% than for a free-draining coil.

Notes: Homopolymers of 2,3-epoxypropyl methacrylate with various molecular masses were prepared by solution polymerization with 2,2′-azoisobutyronitrile as initiator. The effect of polymerization conditions on the molecular parameters (weight- and number-average molecular masses MW and Mn intrinsic viscosity [η]) and the tacticity of the resulting poly (2,3-epoxypropyl methacrylate)s was investigated. For unfractionated polymers, the constants of the Mark-Houwink equation for 1,4-dioxane and tetrahydrofuran were determined. Gel permeation chromatography was tested as a tool for the determination of the Mw and Mn values.

Notes: The presence of the α-methyl group in the alternating methyl methacrylate-styrene copolymer produces a remarkable difference in its 13C NMR spectra as compared with the spectra of the alternating methyl acrylate-styrene copolymer; cotacticity-dependent splittings occur only in the former spectrum. A theoretical interpretation was attempted for this characteristic spectral variation in terms of the calculated time-averaged chemical shifts for carbons in the dyads constituting the alternating copolymers. Each (meso or racemic) dyad sequence is considered to exist in several conformational states which are mutually exchanging rapidly and the probabilities of which are determined by a statistical mechanical procedure. The calculation of cotacticity-dependent chemical shifts is conducted for the side chain carbonyl, aromatic C1 and methoxyl carbons as well as for some main chain carbons to give good agreement with the observed peak splittings, especially with respect to the side chain carbons. In accordance with the reported assignment, the calculated differences in shielding factors between meso and racemic dyads for the side chain carbons of poly(methyl methacrylate-alt-styrene) are positive, i.e. the meso or isotactic peak appears at higher field than the racemic or syndiotactic peak. Furthermore, the resulting values are relatively large (≈0,63 ppm) in conformity with the experiment. The calculation for the carbons in poly(methyl acrylate-alt-styrene) gives a very small shielding difference (-0,04 to 0,06 ppm) by the dyad cotacticity, being consistent with the observation, i. e. absence of peak splittings.

Notes: Tacticity-dependent splittings observed in 1H and 13C NMR spectra of poly(methyl methacrylate) are elucidated by a theoretical procedure which consists of conformational analysis of the polymer chain and shielding calculation. The conformation is analyzed by the statistical mechanical method combined with the force field energy calculation on the dyad sequence models. As significant shielding factors, diamagnetic, anisotropic, and electrostatic terms are taken into account for the chemical shifts of 1H NMR, while paramagnetic, diamagnetic, and anistropic terms are considered for 13C NMR. The calculation is used to assing the α-methyl proton, methoxyl proton, methylene proton, quaternary carbon, methylene carbon, α-methyl carbon, carbonyl carbon, and methoxyl carbon peaks split due to dyad and triad cotacticities. The results are generally consistent with the observed spectra. Especially, the calculated splitting widths are in quantitative agreement with the observed splittings of the methoxyl and α-methyl protons resonances as well as of the carbonyl and α-methyl carbons resonances. Effects of temperature and stereoregularity on the spectra are also discussed.

Notes: The crystal unit cell of a series of normal diamides, R—NHCO—(CH2)2n—CONH—R (1) with R=CH3—(CH2)5— and n varying from 0 up to 4, has been determined from X-ray diffraction patterns of oriented films. This work forms part of the study to investigate the relation between microstructure and physical properties, in particular diamagnetism. The unit cell is tricline for all members of the series having one chain molecule per unit cell. The structure of normal diamides consists of extended chains tilted 75° from the sheet edge allowing hydrogen-bond formation within the sheet. The long spacings obtained have been associated to oblique structures of hydrogen-bonded sheets, except for the diamide with n = 1. A. shear between adjacent hydrogen-bonded sheets of 3 repeating chain units offers the most probable explanation for the structure of 1 with n = 0,2,3 and 4.

Notes: Heteroaggregations of the pair of cyanine dyes pinacyanol and thiacarbocyanine induced by the polyanions poly(potassium styrenesulfonate) and poly(potassium vinyl sulfate), and of methylene blue and acridine orange induced by mercuric chloride are described. In each case the characteristic of heteroaggregation, namely the enhancement of the metachromatic band of the partner dye having λmax at relatively shorter wavelength at the expense of the absorbance at the metachromatic band of the other dye, is reflected in the difference spectra. The dependence of the shape of the metachromatic band of pinacyanol on the nature of the polyanion inducing metachromasia is also reflected in the heteroaggregation of this dye and thiacarbocyanine induced by the two different polyanions. Mercuric chloride, though not a polyanion, also induces strong heteroaggregation of methylene blue and acridine orange.

Notes: The extrapolated melting point of native 1,4-trans-isotactic-polypentadiene obtained by inclusion polymerization in pre-irradiated perhydrotriphenylene is 104°C, 10 K higher than that of a long-annealed conventional polymer. The WAXS spectrum corresponds to that of the already known paracrystalline structure; this notwithstanding, its heat of melting is 20-70% higher than that of polypentadiene crystallized from solution or from the melt. The native polymer shows noteworthy superheating phenomena and is not able to induce crystallization of high-melting crystals from the melt. This behaviour is consistent with that predicted for extended-chain polymeric crystals. This conclusion is supported by the absence of definite peaks in the SAXS spectrum of the native polymer.

Notes: Semi-interpenetrating polymer networks based on polystyrene and polystyrene-polyisoprene three-block copolymers (SIS) were prepared by anionic polymerization. Factors affecting synthesis, such as composition, molecular weight of either the unattached SIS or the polystyrene between crosslinks, elastomer content, have been varied. Their effect on network formation was examined by extraction experiments and swelling measurements. Their morphology was investigated by means of electron microscopy.

Notes: 2-(2-Hydroxy-5-vinylphenyl)-2H-benzotriazole (9) was prepared by a seven step synthesis in about a 25% overall yield starting from o-nitroaniline. Diazotization in aqueous HCl gave a diazonium salt which was coupled with p-ethylphenol to an azo-dye which was reduced with zinc powder in sodium hydroxide solution to 2-(2-hydroxy-5-ethylphenyl)-2H-benzotriazole (4). This compound was acetylated and then brominated with N-bromosuccinimide to 2-[2-acetoxy-5-(1-bromoethyl)phenyl]-2H-benzotriazole (6) which was dehydrobrominated with triethylamine in acetonitrile or tributylamine in dimethylacetamide to the vinyl compound which was hydrolyzed to 9. This monomer was readily homopolymerized and copolymerized with styrene and methyl methacrylate using 2,2′-azobis(2-methylpropionitrile) as initiator.

Notes: The photodecomposition of α-methoxydeoxybenzoin (1) and α,α-dimethoxydeoxybenzoin (2) was investigated both in the absence and in the presence of 1,1-diphenylethylene. The resulting products indicate that benzoyl radicals add to the olefinic double bond (initiation of polymerization), whereas the α-methoxybenzyl radicals generated from 1 do not add to the olefinic double bond (no initiation), but preferentially combine with other radicals (termination of polymerization). This reaction is largely suppressed in the case of α,α-dimethoxybenzyl radicals generated from 2 owing to sequential fragmentation into inactive methylbenzoate and highly reactive methyl radicals which add to the olefinic double bond and thus contribute to the initiation.

Notes: New poly[(amino)amide]s (4) deriving from 1,2,4,5-benzenetetraamine and terephthalic, isophathalic, or 2,5-furandicarboxylic acid (2a-c) were indirectly prepared by detosylation of the corresponding new poly[(tosylamino)amide]s 3, which were obtained by low-temperature solution polymerization of 4,6-ditosylamino-1, 3-phenylenediamine (1) with the dicarboxylic acid dichlorides 2a-c. In a subsequent step the poly[(amino)amide]s were converted by polydehydrocyclocondensation into the heat-resistant aromatic poly(imidazo[4,5-f]benzimidazole)s (5) by heating in a high vacuum. The results of elemental analysis, IR and UV spectroscopy, inherent viscosity measurements, molecular weight determination (osmometry), and thermal analysis (DSC, TG) of the prepared polymers are compared and discussed.

Notes: Butadiene polymerization with hydrogen peroxide resulted in the simultaneous formation of oligomers, polymers, and high polymers. Analyses of their microstructures showed that oligomers have a higher content of 1,2-structures (28%) than the polymers (22%). The nature of the chain ends was determined with low molecular weight compounds. The content of 1,2-units is distinctly higher in the oligomers, which shows that initiation takes place preferably in 1,2- and propagation in 1,4-position. Besides hydroxyl end groups, other functional groups were detected in small quantities in the low molecular weight products: aldehydes, ketones, acids, hydroperoxides, and epoxides. These functions result from secondary reactions such as transfer, initiation, or termination reactions with alcohol releasing radicals.

Notes: The addition of hydroxyl groups on double bonds during the synthesis of unsaturated polyesters is studied with the help of model molecules. These are diesters of unsaturated diacids (maleic and fumaric acids) or monoesters of unsaturated monoacids (crotonic, cinnamic and p-cyanocinnamic acids) with 1,2-propanediol. The addition reaction take place to appreciable extents only with bis(hydroxypropyl) maleate and fumarate. The reaction is catalyzed by strong acids such as p-toluenesulfonic acid; it is reversible and favoured by high temperatures. A mechanism is discussed.

Notes: By means of a Wittig condensation polymerization starting from 4,4′-azodibenzaldehyde (1) and bifunctional Wittig salts of the benzene and thiophene series (2a-c) poly(azo-1, 4-pheny-leneivnylenearylene)s (3a-c) were synthesized. Analogously the model compounds 6a-c, 8a-d, and 10a-c were prepared. The structures of the intensive red to brown polymers and the orange to red model compounds were proved by elemental analyses, IR- and electronic spectra, respectively mass spectral data for the model compounds. The thermooxidative degradation of the polymers and the electrical conductivity of the polymers and model compounds were studied.

Notes: Condensation of 4-aminoazobenzene (1), respectively 4, 4′-diaminoazobenzene (2), with mono- and dialdehydes of the benzene and thiophene series yields intensive coloured polymeric azomethines (polymeric Schiff bases) with azobenzene units, respectively model compounds. The structure of these polymers and model compounds were confirmed by elemental analyses, IR-and electronic spectra and  -  in the case of the model compounds  -  by MS and 1H NMR spectra. The electrical conductivities of the polymers and model compounds and the thermo oxidative degradations of the polymers were studied.

Notes: A few unsaturated polysters prepared by melt polycondensation of maleic anhydride, phthalic anhydride, and aliphatic glycols in different proportions have been characterized. The salient features of the 1H and 13C NMR spectra of the polyesters and of model compounds are compared. It appears that from 15 to 20% of maleic acid residues have reacted with excess glycol to yield branching points while the remaining free olefinic double bonds have undergone cis → trans isomerization almost quantitatively along the oligomeric chains.

Notes: The reaction of 6,6-dimethylfulvene (1) with small amounts of sodium cyclopentadienide (Na-CPD) gives a mixture of oligomeric products, from which 1-cyclopentadienyl-1,3,3,-trimethyltetrahydropentalene (7) was isolated with 67% yield. The structure of the main product 7 was proved by combination of spectrosopic methods as well as by NMR spectroscopy of its dianion. A reasonable reaction mechanism is presented and supported by isolation of other dimers 9 and 12 and trimers 10 as well as of side products 11 and 13. The product distribution is severely influenced by increasing the amount of Na-CPD (favouring oligomers of type 11 and 13) as well as by addition of crown ether.

Notes: Solution properties of poly(A) and poly(I) solution at a mole ratio of poly(A) to poly(I) of 1/2 were studied by means of calorimetry and a modified differential scanning calorimetry (DSC) with the help of circular dichroism (CD) and ultraviolet (UV) spectral methods. It was found that the heat of mixing, ΔHM, depends sharply on the ionic strength. At [NaCl] 〈 10-2 mol · dm-3 ΔHM is nearly zero. At higher ionic strength ΔHM decreases and reaches a minimum value at [NaCl] ≍ 2 · 10-2 mol - dm-3. Above this ionic strength ΔHM increases again. This behavior is explained on the basis of the formation of a triplex poly(A) · poly(2I) and the transition of poly(I) from a disordered to an ordered structure with increasing ionic strength. The heat of formation, ΔH, of the poly(A) · poly(21) triplex was estimated to be ca -41 kJ per mole of base triplet. Above an NaCl concentration of 2 · 10-1 mol · dm-3 the triplex formation may be represented by the following scheme: \documentclass{article}\pagestyle{empty}\begin{document} $$\begin{array}{*{20}c} {{\rm Poly}({\rm A}) + 2{\rm poly}({\rm I})\ ({\rm order})} \hfill \\ {{2\Delta {\rm H}_{\rm t}\atop{-\hskip-1.5pt-\hskip-1.5pt\longrightarrow}} \quad {\rm poly}({\rm A}) + 2{\rm poly}({\rm I})\ ({\rm disorder})} \hfill \\ {{\Delta {\rm H}\atop{-\hskip-1.5pt-\hskip-1.5pt\longrightarrow}} \quad {\rm poly}({\rm A}) \cdot {\rm poly}(2{\rm I}){\rm\ triplex}} \hfill \\ \end{array}$$\end{document}

Notes: Micelles of a block copoymer poly(styrene/butadiene/styrene) with cores consisting of polybutadiene blocks were stabilized in dilute solutions by UV radiation in the presence of a photo-initiator and also by fast electrons, and micelles of a block copolymer poly(styrene/ethene-co-1-butene/styrene) with cores formed by the aliphatic blocks were stabilized by fast electrons, in dilute solutions. Stabilization of micelles, i. e., crosslinking of the chains in micellar cores as well as the properties of stabilized micelles were studied by conventional light scattering, by light scattering photon correlation spectroscopy and by gel permeation chromatography.

Notes: The polymorphic behaviour of polymers \documentclass{article}\pagestyle{empty}\begin{document}$% MathType!MTEF!2!1!+- % feaaeaart1ev0aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGabeikayaaqa % Gaae4taiaab+eacaqGdbGaeyOeI0IaaeikaiaaboeacaqGibWaaSba % aSqaaiaabkdaaeqaaOGaaeykamaaBaaaleaacaqGUbGaaeylaiaabk % daaeqaaOGaeyOeI0Iaae4qaiaab+eacaqGpbGaeyOeI0Iaae4qamaa % BaaaleaacaqG2aaabeaakiaabIeadaWgaaWcbaGaaeinaaqabaGccq % GHsislcaqGdbGaaeikaiaaboeacaqGibWaaSbaaSqaaiaabodaaeqa % aOGaaeykaiaab2dacaqGdbGaaeisaiabgkHiTiaaboeadaWgaaWcba % GaaeOnaaqabaGccaqGibWaaSbaaSqaaiaabsdaaeqaaOGabeykayaa % qaWaaSbaaSqaaiaabIfaaeqaaaaa!560E! {\rm \rlap{--} (OOC} - {\rm (CH}_{\rm 2} {\rm )}_{{\rm n - 2}} - {\rm COO} - {\rm C}_{\rm 6} {\rm H}_{\rm 4} - {\rm C(CH}_{\rm 3} {\rm ) = CH} - {\rm C}_{\rm 6} {\rm H}_{\rm 4} {\rm \rlap{--} )}_{\rm X} $\end{document}(n = 8, 10) has been investigated. They show thermotropic, mesophasic properties with a nematic structure. Both polymers exhibit a multiple solid state polymorphism which is a function of the temperature and of their thermal history.

Notes: As a part of studies on wholly aromatic polyamides containing bridged biphenylylene groups, poly(3,8-phenanthridinonediyl terephthalamide) (DAP-T) was prepared from 3,8-diaminophenanthridinone and terephthaloyl chloride. The solutions of DAP-T samples in high concentration sulfuric acid exhibited optically different phases, depending on temperature and concentration, like those of poly(1,4-phenylene terephthalamide) (PPD-T). The phase diagram of the DAP-T-99,0% H2SO4 system was established and compared with that of the PPD-T-99,0% H2SO4 system. Both were essentially similar. The flow of high concentration dopes of DAP-T and PPD-T through spinneret holes showed non-Newtonian characteristics. The liquid-crystalline solutions of DAP-T in 99,0% sulfuric acid were spun into fibers using water as a coagulant. The tensile strength and initial modulus increased with increasing degree of stretching between spinneret and collection roller. The annealing of fibers caused an increase in tenacity and modulus, and a tensile strength of 25 g/den and an initial modulus of 1 000 g/den could be reached. Both spun fibers and annealed fibers showed x-ray diffraction patterns displaying distinct layer line streaks, from which the fiber period was estimated to be 17,2 Å. This agreed with the repeat distance in the direction of molecular axis calculated on the basis of extended chains with trans-conformation.

Notes: A new method for the determination of the cmc using a dialysis technique which allows monomeric species to diffuse through but not micelles has been applied for determining the mixed micelle composition. The method is based on determining the amount of surfactant that diffuses through at two different times which allows for the calculation of the cmc by use of the appropriate equation. This method requires the preparation of only one concentration of solution and lends itself particularly well to the determination of the composition of mixed micelles.

Notes: A number of wholly aromatic copolyamides containing bridged biphenylylene groups were synthesized from a mixture of aromatic diamines and terephthaloyl chloride, on one hand, and from a mixture of aromatic diacid dichlorides and 1,4-phenylenediamine, on the other hand. Each mixture of diamines and of diacid dichlorides was constituted of a phenylene derivative and a bridged biphenylylene derivative. The copolyamides synthesized were dissolved in high concentration sulfuric acid and spun into fibers. The fibers spun showed fairly high tensile strengths and high initial moduli, but annealing caused further increase in strength and modulus. All the copolyamides studied had very high thermal resistances.

Notes: Practical hints for the application of the indirect Fourier transformation method are given. In detail there are discussed the problems of stabilization of the least squares routine, the estimation of the maximum dimension of the particles, the choice of an appropriate number of the spline functions, the combination of scattering functions measured with different primary beam geometry, standard deviation and error propagation of the solution functions, influence of the interparticle interference effect and background scattering on the results, determination of the radius of gyration and the scattering intensity at zero angle and finally the possibility of simulation of measuring curves starting with model bodies is described. It is attempted to demonstrate the advantages of indirect Fourier transformation on hand of several practical examples.

Notes: Systematic studies were performed on interpolymer complex formation between Poly(acrylic acid) (PAA) and poly(ethylene oxide) (PEO) in THF-water mixtures of different compositions. Viscosity behaviour during complex formation in mixed solvents was found to be entirely different from that observed by other workers in aqueous and in pure organic solvents. The result are interpreted in terms of, (a) preferential solvation of the polymer, (b) Probable change in conformation of the polyelectrolyte moleculer. (c) association of complex molecules in a medium of low dielectric constant, and (d) expected disordering of bound water molecules around PEO by THF. Irrespective of solvent composition, interpolymer complex of PAA and PEO was always found to have 1:1 unit mole ratio.

Notes: Non-Newtonian viscosity could be explained by the Graessely entanglement viscosity theory modified by a frictional viscosity for moderately concentrated solutions of polydimethyIsiloxanes over a range of shear rates from lower to upper-Newtonian flow. The expansion of a polymer molecule was kept under control by use of solvents with different dissolving powers of the polymer. The result shows that only the frictional viscosity is strongly related to the degree of expansion of a polymer molecule in solution and that Graessley's plots are independent of that. Extrapolation of the frictional viscosity versus concentration curves to 100wt.-% show a common value of 0,09 Pa·s in spite of different degrees of expansion of the polymer molecules in solution. This common value was equal to the viscosity value for melt polymer with the same molecular weight as a polymer segment. It is concluded that the frictional viscosity is caused by solvent-solvent, solvent-polymer segment, and segment-segment interactions.

Notes: A modified method for the determination of the number of isotactic sites C* and the overall propagation rate constant k̄p of propene polymerization catalysts with 14C-labelled carbon oxides is proposed: an excess of 14CO2 or 14CO is added in the abscence of propene and alkylaluminium to a non-deactivated polymer sample drawn from the polymerization slurry.The specific radioactivity of the polymer as a function of the time of contact with the radio-actively labelled inhibitor sharply increases within short times of contact (14CO2 ≤ 20 min, 14CO ≤ 5 min). This is followed by a slower further increase reaching a finite value after 5 to 7h. The initial and end values differ by a factor of 2 to 3. The results are explained in terms of sites with different reactivity assuming that the total number of isotactic sites is determined only after long times of contact with the inhibitor.So far c* was determined with 14CO2 or 14CO by adding the inhibitor during the polymerization in the presence of propene and alkylaluminium; c* was calculated after short times of contact with the inhibitor, whereas the further steady increase in specific radioactivity was exclusively attributed to side reactions caused by reaction with propene and alkylaluminium.By this modified method we obtained for TiCl3·(1/3)AlCl3 at 60°C k̄p = 13 dm3/(mol·s) and c* = 0,012 mol Ti*/mol Titotal. Addition of a free Lewis base to the polymerization mixture increases c* leaving k̄p unchanged. In contrast to this, if TiCl3·(1/3) AlCl3 is milled with a Lewis base k̄p can be increased by a factor of ≈ 2,5 with lower or equal c* -values. The higher activity of extracted TiCl3-catalyst is due to higher k̄p and c* -values as compared to those using TiCl3·(1/3) AlCl3.

Notes: Coordination polymers, \documentclass{article}\pagestyle{empty}\begin{document}$% MathType!MTEF!2!1!+- % feaaeaart1ev0aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGabeikayaaqa % GaaeytaiaabshacaqGmbGabeykayaaqaWaaSbaaSqaaiaab6gaaeqa % aaaa!3B21! {\rm \rlap{--} (MtL\rlap{--} )}_{\rm n} $\end{document} were synthesized by condensation of bis(salicylaldehydo)-metal(II) (metal = Co, Ni, and Cu) with diamines (1, 4-diaminobenzene and 4,4′-diaminobiphenyl). Their composition, structure, thermal stability, and physical properties were investigated by analytical, magnetic, spectral (IR and DRS), the thermogravimetric studies. It was found that in the bis(salicylaldehydo)metal(II)-chelates, two salicylaldehyde molecules are linked to each metal ion through the oxygen atoms of the phenolic and aldehydic groups and in the polymeric complexes the nitrogen atoms of the amino groups replace the aldehyde oxygens. The diamine molecule is thus acting as a bridging unit between two salicylaldehydometal(II) units, forming structures 1 and 2. The polymers obtained from 4,4′-diaminobiphenyl (2a-c) are thermally more stable than those from 1, 4-diaminobenzene (1a-c), the order of thermal stability in both cases being Ni(II) 〉 Cu(II) 〉 Co(II). Co(II) and Cu(II)-complexes are paramagnetic, whereas Ni(II)-complexes are diamagnetic. The reflectance spectra along with the magnetic data suggest a square planar structure for Cu(II) and Ni(II)-complexes, and a tetrahedral one for the Co(II)-complexes.

Notes: The nature of alkali derivatives of acetone (ADA) and active centres (AC) in the anionic polymerization of isopropenyl methyl ket one (IMK) was studied by means of IR spectroscopy. Solutions of ADA and of the AC of IMK in tetrahydrofuran show a characteristic absorption at 1560 - 1610 cm-1, due to the stretching vibrations of the delocalized isopropenyl oxide group. Two kinds of equimolar complexes are formed between acetone and ADA, depending on the nature of the counterion (Li+, Na+, K+, Cs+). The same interaction is observed between the AC of oligo (IMK) and the carbonyl group of the last but one monomeric unit (penultimate effect).

Notes: Previous Kinetic studies of the emulsion polymerisation of the three component system acrylonitrile (A)  -  styrene (S)  -  methyl acrylate (M) have shown that S is much more reactive than A and M, which have practically the same reactivities. As a consequence, in batch process a large copolymer composition drift is observed versus conversion. To avoid this damageable drift, two techniques were investigated, to get homogeneous macromolecules. (1) Application of the well known “semi-continuous technique” which appeared not to be totally satisfactory, since the initial batch polymer fraction generally has a composition different from the further polymer when the monomer feed is added under starving conditions; a mixture of various macromolecules is the result. (2) The use of the composition controlled reactor, developed in this laboratory, which consists in a continuous monitored readjustment of monomer feed composition. However, due to the heterogeneous medium of an emulsion copolymerization, the copolymer exerts a small chemical heterogeneity which may be practically negligible at high monomer/water ratio. It is finally proposed that a thermodynamic approach might overcome such a behaviour and insure an actual control of the copolymer composition.

Notes: The interaction of Ni[P(OR)3]4 (R = C2H5 or C6H5) with chlorinated rubber (CR) of CCl4 is studied. The results of the polymerization of methyl methacrylate (MMA) initiated by the system CR or CCl4—Ni[P(OR)3]4 depend on the order in which the reagents are introduced. Trialkylphosphite, tetrakis(trialkylphosphite) nickel and the products resulting from the reaction of CCl4 or CR with Ni[P(OR)3]4 are characterized by 31P NMR. From this study, it appears that the initiation of polymerization by the system chlorinated compound-nickel derivative does not involve the formation of free phosphite, which is at variance with previously reported assumption. 1H NMR study supports these results.

Notes: The reaction of a diisocyanate and an asymmetric aliphatic-aromatic diacid containing a preformed imide group was studied in order to obtain polyamide-imides. It is shown in this paper that combined 1H and 13C NMR spectrometry will permit the quantitative evaluation of the proportions of head-tail, head-head, tail-tail additions, provided the content of urea in the polymer is low. In order to obtain unequivocal assignments and to thoroughly characterize the NMR spectra of the polymer, several model compounds resembling the polymer backbone were synthesized. A model polymer was synthesized with the same purpose, and its 1H and 13C NMR spectra fully assigned. Unexpected chemical functions in the polymer, like urea and carboxylic acid, can also be easily detected and quantified by NMR.

Notes: The polycondensation of 4,4′-methylenediphenylisocyanate and 6-(4-carboxyphthalimido)-hexanoic acid was studied under different conditions in order to establish the influence of factors such as temperature, catalyst, stoichiometric disbalance, and addition order of reactants on the molecular weight and the chemical composition of the final polyamide-imide. All these factors proved to influence the extent of possible side reactions that lead to undersirable functions, the main ones being urea functions that locate within the polymer backbone. Other side-reactions proposed to explain the formation of acylureas or biurets did not take place in appreciable extent since these functions could not be detected by NMR spectroscopy. Therefore, particular emphasis was made to prevent the formation of urea by changing the polycondensation conditions. A first attempt to clarify the regularity degree of the polymers (amounts of head to tail and head to head addition) by 1H NMR spectroscopy was also made.

Notes: The viscosity of dilute solutions of poly(ethyl methacrylate) in each of methyl acetate, ethyl acetate and isobutyl acetate was studied over the temperature range of 20-65°C. The intrinsic viscosity either remained approximately constant or slightly decreased over the temperature range because of conformational changes. The temperature ranges of conformational change were 40-50°C, 40-50°C, and 35-55°C for the polymer in methyl acetate, ethyl acetate, and isobutyl acetate, respectively. The Huggins constant was also influenced by the type of solvent and by temperature changes, especially over the temperature range in which conformational changes took place. Conformational changes of poly(ethyl methacrylate) in aliphatic organic esters as solvents are believed to be due to changes in the interaction between the polymer segments and the solvent.

Notes: Poly(pentamethylene sulfide)Structure-based name: poly(thiopentamethylene). (P5MS) [—S(CH2)5—]x was prepared by the condensation polymerization of nearly equimolar amounts of pentamethylene dibromide and the sodium salt of 1,5-pentanedithiol. Selective precipitations were used to obtain a fraction of the polymer, and dielectric constant measurements on solutions of it in benzene were used to obtain dipole moments over the range 20-60°C. Rotational isomeric state calculations based on conformational energies obtained from semiempirical potential energy functions gave results in fair agreement with experiment. Since extensive previous studies on a number of polyoxides have demonstrated the difficulty in calculating the energy of the O…CH2 interactions, the energy of the corresponding S…CH2 interactions in P5MS was adjusted to obtain better agreement between theory and experiment.

Notes: The copolymerization parameters of 2-acryloyoxybenzoic (AOB) and 2-methacryloyloxybenzoic (MOB) acids, methyl 2-methacryloyloxybenzoate (MMOB), and N-methyl-N-phenyl-2-aminoethyl methacrylate (MPAM) with styrene in benzene solution were determined and used in the calculation of the Alfrey-Price copolymerization constants e and Q for AOB, MOB, MMOB, and MPAM. Using e Q thus determined and the corresponding tabulated values for methacrylic acid (MAA), the copolymerization parameters of pairs AOB-MPAM, MOB-MPAM, MMOB-MPAM, and MAA-MPAM were calculated. They are compared with those determined by the copolymerization of these pairs in which the interaction of functional groups on comonomers plays a role.

Notes: Poly(vinyl chloride) of low molecular weight (the fraction extracted with a hexane/acetone mixture (vol.-ratio 3:2)) was substituted by hydroxyphenyl groups and then analyzed by 1H NMR spectroscopy. It was established that the 1H NMR spectra of hydroxyphenyl substituted poly(vinyl chloride) prepared by removal of HCl, allows to determine the number of unsaturated end groups and to distinguish between the structures —CHCl—CH2—CH=CH—CH2Cl and —CH2—CHCl—CH=CH—CH2Cl, and even between their trans and cis forms. In addition the 1H NMR spectra of hydroxyphenyl substituted poly(vinyl chloride) prepared without removal of HCl allow to determine the total number of unsaturated end groups.

Notes: The polymerization of 2-pyrrolidone (1) initiated with its potassium salt (2-oxo-1-pyrrolidinylpotassium) (2) and accelerated by the presence of CO2, was investigated. For the optimal concentration of 2 (≈5 mol-%) and 0,5 mol-% CO2, the most suitable polymerization temperature was found to the range between 45 and 55°C. The variation of CO2 concentration, 0,5 〈 [CO2] 〈 3 mol-%, does not affect the polymerization yield under the optimal conditions. The similarity of the course of polymerization in the presence of CO2 directly introduced into the reaction mixture with that in the presence of isolated carboxylate of 1, is considered as a proof that CO2 is transformed into the active potassium carboxylate of 1. The order of polymerization reaction with respect to initiator was found to be ≈0,8 indicating the complexity of the reaction mechanism.

Notes: The anionic polymerization of 1,3 and 1,4-diisopropenylbenzene (DIB) was found to be characterized by a rather low ceiling temperature and by rather strong differences in reactivity between the two double bonds. At low degrees of conversion the polymers formed are essentially linear and carry one pendant double bond per monomeric unit. Branching and crosslinking can occur only at higher conversion. 1,3-DIB can be copolymerized anionically with α-methylstyrene. Grafting reactions were carried out on polymer backbones with pendant unsaturated groups, using two different pathways. The occurence of coupling reaction can be avoided by a proper choice of experimental conditions.

Notes: From Witting-reactions of dithieno[3,2-b: 2′, 3′-d]thiophene-2, 6-dicarboxaldephyde (1) with “mono-and bis-Wittig-salts” of the benzene and thiophene series poly(dithieno[3,2-b: 2′,3′-d]-thiophene-2,6-diylvinylenearylenevinylene)s 3a - c and some model compounds 5a - c were obtained. Wittig-reactions of dithieno[3,2-b: 2′,3-d]thiophene-2-carboxaldehyde (6) with “mono-and bis-Wittig-salts” gave model compounds 7a - c and 8a, c. The structures of all compounds were confirmed by elements analyses, IR-and electronic spectra, those of the model compounds additionally by mass spectra, and in case of sufficient solubility by 1 H NMR spectra. The electrical conductivities of all compounds and the thermooxidactive degradation of the polymers 3a, c were investigated.

Notes: In contrast to conventional approaches to active centre determination in Ziegler-Natta polymerization, a method is proposed whereby the active catalyst rather than the polymerization system as a whole is studied. The method is based on the observation that addition of non-polymerizable olefins such as α-methylstyrene to catalyst systems promoted with Al(iBu)3 leads to displacement of isobutene from the active sites. Active site concentration are derived from quantitative determination of liberated isobutene or labelled cumene derived by quenching the treated catalyst with [O-3-H]-methanol. Values of active site concentration were found to be of the order of 0,3 mmol per mol of V and 2,6 mmol per mol of Ti for VCl3 and TiCl3. AA catalysts, respectively.

Notes: A series of polysters based on a triad aromatic ester mesogenic unit but containing different poly(alkylene oxide) flexible spacers in the main chain was prepared and its properties examined. The flexible spacers consisted of poly(alkylene oxide)s of varying lengths based on either oligomers of ethylene oxide or propylene oxide. The spacer types, lengths and distributions were found to strongly affect the mesophase and melting behaviors of the polymers. Polymers with spacers having more than 10 units were not liquid crystalline, whereas those of shorter length exhibited mesophase properties. The polymers containing spacers with two, three, or four oxyethylene units showed two mesophases, and the textures of their mesophases suggested that both smectic and nematic phases were formed.

Notes: In the reaction of methyl methacrylate (2) with methyl 2-sodioisobutrate (1) (a model of the active center in the anionic polymerization of 2) in a mole ratio of 2:1, the concentrations of all known initial compounds and reaction products were estimated. This reaction was studied in a flow reactor with reaction times between 0,02 and 1,4 s using GLC, LC and GPC as analytical methods. At the same time, a rise in temperature of the reaction mixture by 6°C was observed (for [2] = 0,2 mol/1); at a higher concentration of 2 (0,6 mol/1), this rise was 27°C and hence not negligible in the interpretation of the results. The concentration changes of the individual products were in accordance with the concept of a stepwise addition of 2, to the metalloesters. At the end of the reaction the mean molecular weight of the addition products corresponded roughly to the ratio 2/effective 1. The cyclization of Na-trimer 4a to a cyclic trimer 9 was shown to be an important side reaction. The Na-tetramer 5a and the higher Na-oligomers 6a probably undergo a similar cyclization. 2 added 1 very quickly; the following approximate order of reaction rates (Scheme 1) is proposed: R1 〉 R2, R3, R4, … 〉 Rc.

Notes: Linear poly(iminoethylene) was synthetised by cationic polymerization of 2-methyl-2-oxazoline using BF3—O(C2H5)2, SnCl4, and CH3COBF4 as initiators and in the presence or absence of CH3CN. The resulting product, poly(N-acetyliminoethylene), was then hydrolysed in basic medium. The resulting poly(iminoethylene) was identified and characterized by 1H NMR, 13C NMR, X-ray diffraction, and differential scanning calorimetry (DSC). The synthetised polymer will be used as a polymeric support in ionic-exchange resins as well as in macromolecular pesticides.

Notes: A new polyesterimide containg CC-double bonds was prepared by reacting an unsaturated diacid chloride containing a cyclic imido group with ethylene glycol at low temperature. The solubility, thermal, electrical and cross-linking properties of the polymer were studied. The polymer was found to be thermostable and soluble in highly polar solvents. X-ray diffraction data revealed that the polymer is crystalline. The unsaturation sites of the polymer chain could be exploited for crosslinking reactions. The swelling behavior of the crosslinked polymer was studied as well as the thermal and electrical properties. The overall thermal stability of the crosslinked polymer was found to be higher than that of the uncrosslinked polymer.

Notes: It was found that three polyconjugated polymers with anthrancene repeating units slow down the thermal and thermooxidative degradation of polystyrene. This effect is explained by charge transfer complex formation between the radicals formed during the degradation of polystyrene and the polyconjugated polymers as donors.

Notes: Preparation and characterization (by IR and 1H NMR spectroscopy) of isomeric methacrylic acid and acrylic acid derivatives of the herbicide 3-amino-1,2,4-traizole are described. Their radical polymerization and copolymerization with styrene or methyl methacrylate give polymers containing the herbicide moiety as pendant groups bound via acyl groups at the amino group or at the ring nitrogen. The reactivity ratios were determined for the isomeric methacrylic compounds.

Notes: Monofunctional telomers of vinyl chloride (1) were synthesized by two ways. In the first one, the telomers resulting from the reaction of 1 with carbon tetrachloride were used as telogenic agents to react with allyl acetate leading to a monoadduct. In the second one, monofunctional telogens were used in a redox catalyzed reaction with 1. Trichloroacetic acid and its esters (2b-d) were applied as telogens. The theoretical maximum yields and the number average degrees of polymerization at these yields were calculated and compared with the experimental results.

Notes: The nature of interactions between polyethylene and a non-wetting solute was analyzed to know if the interface can be characterized by the expression of the energy of wetting or if phenomena other than adhesion and wetting must be taken into account. In this way, the isotherms of sorption, the molar heats of interaction, the kinetic behaviour of the sorption, the permeation, and the changes of length during liquid immersion gave informations on the existence of a limited diffusion into the polymer. Two types of systems were investigated: polyethylene/water and polyethylene/methylene iodide. The formation of aggregates is discussed.

Notes: The kinetics of the thermal dehydrochlorination of PVC was investigated with respect to the initiation mechanism of the hydrogen chloride chain elimination. The constant rate of dehydrochlorination in the early stages of the dehydrochlorination process is explained by an intra-chain initiation mechanism which is a consequence of a constant amount of active sites (structural irregularities) incorporated in the chains. After an initial period, dehydrochlorination is occurring in a random way, and (or) by an inter-chain dehydrochlorination mechanism initiated by a “sudden polarization” effect between the postulated zwitterion and a meanwhile unreacted —CH2CHCl— group.

Notes: The synthesis of 4-formyl-3-hydroxy-5-methacryloylaminomethyl-2-methylpyridine (7a) and 4-formyl-3-hydroxy-5-(N-methacryloyl-N-methyl)aminomethyl-2-methylpyridine (7b) is reported. The intermediate products 5-aminomethyl-2,2,8-trimethyl-2H,4H-[1,3]-dioxino[4,5-c]-pyridine hydrochloride (3a), 2,2,8-trimethyl-5-methylaminomethyl-2H,4H-[1,3]-dioxino[4,5-c]-pyridine hydrochloride (3b), 5-methacryloylaminomethyl-2,2,8-trimethyl-2H,4H-[1,3]-dioxino-[4,5-c]pyridine hydrochloride (5a), 5-(N-methacryloyl-N-methyl)aminomethyl-2,2,8-trimethyl-2H,4H-[1,3]-dioxino-[4,5-c]pyridine hydrochloride (5b), 3-hydroxy-4-hydroxymethyl-5-metha-cryloylaminomethyl-2-methylpyridine (6a) and 3-hydroxy-4-hydroxymethyl-5-(N-methacryloyl-N-methyl)aminomethyl-2-methylpyridine (6b) were isolated and identified.

Notes: The anionic polymerization of 2-pyrrolidone (3) initiated with its potassium salt (1) (2-oxo-1-pyrrolidinylpotassium) and carbon dioxide was studied under optimal conditions. On the basis of a detailed experimental analysis, it is suggested to consider the investigated polymerization in the presence of gaseous CO2 as an accelerated non-activated polymerization. Alkali 2-oxo-1-pyrrolidine carboxylate, which is formed in the system by reaction of CO2 with 1, probably does not take part directly in the polymerization process and excerts only a controlling role.

Notes: 5-Hydroxy-7-methoxy-2,2-dimethyl-6-octyl(and 8-octyl)-4-chromanones (2a and 2b) were synthesized via 5,7 dihydroxy-2,2-dimethyl-6-octyl (and 8-octyl)-4-chromanones (1a and 1b) from phloroglucinol as a starting material. Cyclohexane solutions of 1a, 1b, 2a, and 2b were irradiated. The photostability of 2a and 2b was found to be better than that of 1a and 1b. Poly(vinyl chloride) film containing 6, 7 wt.-% of 2b was found to be most stable against photooxidation.

Notes: Poly(A + U), the 1:1 complex of poly(riboadenylic acid), poly A, and poly(ribouridylic acid), poly U, at pH 8 and self-complexed poly A at pH 4 exist as double helices in dilute aqueous solution. These complexes exhibit a similar behavior as native calf thymus DNA upon irradiation with 16 MeV electron pulses. Thus time resolved Rayleight light scattering measurements showed that crosslinking and double strand breakage can be clearly separated, the former proceeding faster than the latter. The extent to which the two processes occur depends on the ionic strength of the solution. At ionic strenghts exceeding 10 -1 mol/l crosslinking is the dominant process indicating that hcrit, the critical length between two single strand breaks for the accomplishment of double strand breaks, is strongly reduced. The investigation of complexes of poly A and Mg2+ ions revealed that the destruction of salt bridges is the rate determining process for the decrease of the light scattering intensity due to mainchain scission. This implies that life-times of salt bridges can be determined.

Notes: The kinetics of the high-pressure ethylene polymerization initiated by di-tert-butyl peroxide were measured via quantitative near-infrared spectroscopy at temperatures between 130°C and 165°C to a maximum pressure of 3 kbar. The overall polymerization rate was found to be first order in ethylene concentration and of the order 0,5 in peroxide concentration. The overall activation energy and the overall activation volume were determined to be E0 = 107,2 ± 7,5 kJ · mol-1 and Δ V0≠ = - 17,5 ± 5,0 cm3 · mol-1, respectively. From the overall quantities and from the decomposition rate of di-tert-butyl peroxide determined in independent spectroscopic high-pressure high-temperature experiments, kp · kt-1/2 (kp and kt are the propagation and termination rate constants, respectively) and the corresponding activation parameters, Ep - 1/2 Et and Δ vp≠ - 1/2 Δvt≠, were derived for the high-pressure ethylene polymerization. These data enable the overall polymerization rate to be determined also for high-pressure ethylene polymerizations initiated in any different way, provided the initiation rate law is known. The procedure is illustrated for the ethylene polymerization initiated by tert-butyl peroxypivalate.

Notes: Polymers with different fractions of azobenzene residues were prepared by radical copolymerization of methacrylic acid with 4′-phenylazomethacrylanilid. The triplet excitation energy transfer from methylene blue (1) to the azobenzene residues in the polymers was investigated by using the 1-photosensitized cis → trans isomerization of the azobenzene residue. The efficiency of the triplet excitation energy transfer from 1 to 4-(4′-phenylazoanilinocarbonyl)butanoic acid (4) as a monomer model compound. The number of azobenzene residues per polymer molecule and the molecular weight of the polymer were important factors for the efficient triplet excitation energy transfer. On addition of NaCl the energy transfer efficiency was lowered, suggesting that the binding of 1 to the polymer by electrostatic forces plays an important role. Binding of 1 to the polymers was investigated spectrophotometrically. Correlation with the binding of 1 to the polymers and the efficiency of triplet excitation energy transfer between 1 and azobenzene residues in the polymers is discussed.

Notes: In order to calculate the average molecular weight, the molecular weight distribution or the branching of low density polyethylene, the individual values of the rate constants of the different reactions involved in the free radical polymerization are required. The method of rotating sector was applied to determine the rate constants of chain propagation and chain termination in a wide range of temperatures and pressures. This first part of the work reports the influence of the pressure. It was found that the rate constant kp of the chain propagation increases with rising pressure whereas the rate constant kt of chain termination decreases. The effect of the pressure on kp can be explained in terms of the activation volume. The decrease of kt with pressure is caused by a diffusion controlled termination reaction.

Notes: The mechanism of “flow process” defined as drawing by which neither crystallization nor molecular orientation takes place was clarified on the basis of its direct experimental evidences on drawing of “amorphous” poly(ethylene terephthalate) films. In a certain temperature range above Tg, the polymer molecules are deformed and oriented on drawing, “inter-molecular secondary linkage” playing an important role in the transmission of the applied force. When this intermolecular linkage breaks down above a certain critical temperature, the polymer molecules may slip past each other and flow independently, resulting in a large deformation without inducing any molecular orientation and crystallization. At higher temperatures crystallization occurs inducing the orientation as well.

Notes: Sulfuryl chloride was used as chlorination agent of poly(dimethylsiloxane)s (1) in order to obtain poly(dimethylsiloxane-co-chloromethylmethylsiloxane) and it was found to be more specific than molecular chlorine. Identification of chlorinated and chlorosulfonated units was shown to be possible by comparison of the results of 1H NMR spectroscopy with those obtained by GLC analysis of the mixtures obtained from octamethylcyclotetrasiloxane (2). After having shown that the distribution of the various types of methyl groups in 1 and 2, modified in this way, fits correctly a binomial law and that chlorosulfonated units can be hydrolysed, copolymers containing 20 to 25% of chloromethylated units and less than 2% of unwanted dichloromethylated units are accessible by use of this chlorination agent.

Notes: The synthesis and the phase behaviour of liquid crystalline main chain polymers are described. In these poly- and copolyesters the mesogenic units are linked by highly flexible oligodimethylsiloxane spacers. The comparison of their phase behaviour with that of polyesters known from the literature shows that dimethylsiloxane spacers as a replacement for alkyl spacers are leading to a drastic decrease of the transition temperatures. Depending on the length of the spacer glass transitions as low as -111°C can be achieved. The widths of the liquid crystalline phases thereby are retained up to a spacerlength of 13 oxydimethylsilanediyl (dimethylsiloxane) units. The homopolyesters mainly show smectic phases. In contrast to this nematic phases are found for copolyesters in which either the spacerlength or the mesogenic unit was varied. In one case a nematic phase was found over a temperature range of 311°C.

Notes: The kind of molecular weight average MVPO resulting from vapour pressure osmometry (VPO) measurements on solutions of paucimolecular polymer mixtures of different compositions is studied with a Hewlett Packard Model 302 B. Recent theoretical calculations which predicted that MVPO 〉 Mn are confirmed. The experimentally found quotient MVPOMn is between 1,04 and 1,26, being the greater, the greater is the polydispersity of the mixture, which is agreement with the former mathematical derivations.

Notes: Due to its importance in the field of block-polycondensation and of chemical modification, we carried out an extensive study of the epoxy-carboxy reaction on models. This papier is related to the reaction of benzoic acid with 1-phenoxy-2,3-epoxypropane in the presence of a basic catalyst, N,N-dimethyldodecylamine. It is carried out in low polar solvents (xylene, chlorobenzene, and o-dichlorobenzene); essential kinetic parameters are reported. From studies carried out under stoichiometric or non-stoichiometric conditions a general rate equation (υ = k [acid]0.5 [epoxy] [amine]) is obtained. Kinetic relations are the same, no matter what the catalyst is: dimethyldodecylammonium benzoate or free amine. From these kinetic data it results that the overall mechanism involves two steps.

Notes: A method is developed for the conformational analysis of copolymers with randomly distributed stereo- and comonomer-sequences. The conformational probabilities of dyad sequences constituting a random copolymer chain are calculated as a function of the copolymer composition which is derived from the monomer reactivity ratios and the comonomer feed ratio. The applicability of this method is verified in the conformational analyses of poly(methyl acrylate-co-styrene) and poly(methyl methacrylate-co-styrene). The calculation indicates that the conformational stabilities of dyad sequences are scarcely dependent on the copolymer composition in the former copolymer, whereas they are susceptible to the composition in the latter copolymer. This conformational behavior apparently reflects the geometrical difference between the copolymers: the former is composed of two mono-substituted monomers and the latter of sterically nonequivalent monomers, viz. mono- and di-substituted vinyl compounds. The composition-dependences of 13C NMR chemical shifts of these copolymers are interpreted, based on the conformational calculation by this method.

Notes: The epoxy resins (DGEBA) obtained from 4,4′-isopropylidendiphenol (bisphenol A) and 1-chloro-2,3-epoxypropane (epichlorohydrin) and synthetized by the “taffy” process were found to consist of oligomers. The composition of prepolymers could be deduced from gel permeation chromatography (GPC), and particularly by high pressure liquid chromatography (HPLC). In the more resolved HPLC spectrum each oligomer was found to be accompanied by satellite peaks. The functionality of the prepolymers, determined by 1H NMR spectroscopy and cryometric or vapour pressure osmometric measurements was found to be less than two. These phenomena are due to the existence of abnormal chain ends having no epoxy group. The structure of the main components spearated by preparative GPC was studied by 1H NMR. For the impurities, the two indentified structures of chain ends are primary and secondary alcohol functions. Finally the compositions of three DGEBA were determined.

Notes: The glass transition temperature of the random copolyesters of poly(ethylene terephthalate) and p-hydroxybenzoic acid prepared by molten state polycondensation increases with increasing concentration of p-oxybenzoate units (oxy-1,4-phenylenecarbonyl units). The observed values of the glass transition temperature are compared with the values predicted from various empirical equations on the Tg's of copolymers and the concave Tg composition curve is explained in terms of the internal stiffening effect of the p-oxybenzoate unit. The melting temperatures of the copolyesters vary with composition and show an eutectic phase diagram. The melting temperature and enthalpy of fusion of the homopolymer of p-hydroxybenzoic acid were determined making use of Flory's equation on the melting point of a copolymer.

Notes: Semiflexible mesophasic polymers of the general formula \documentclass{article}\pagestyle{empty}\begin{document}$ % MathType!MTEF!2!1!+- % feaaeaart1ev0aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGabi4wayaaqa % Gaae4taiaab+eacaqGdbGaaeikaiaaboeacaqGibWaaSbaaSqaaiaa % bkdaaeqaaOGaaeykamaaBaaaleaacaWGUbGaeyOeI0IaaGOmaaqaba % GccqGHsislcaqGdbGaae4taiaab+eacqGHsislcaqGsbWaaWbaaSqa % beaacaaIXaaaaOGabiyxayaaqaWaaSbaaSqaaiaabIfaaeqaaOGaai % ilaiaad6gacqGH9aqpcaaI5aGaaiilaiaaigdacaaIXaGaaiilaiaa % igdacaaIZaGaaiilaiqacUfagaaeaiaab+eacaqGpbGaae4qaiaabI % cacaqGdbGaaeisamaaBaaaleaacaqGYaaabeaakiaacMcadaWgaaWc % baGaamOBaiabgkHiTiaaikdaaeqaaOGaaiylaiaaboeacaqGpbGaae % 4taiabgkHiTiaabkfadaahaaWcbeqaaiaaikdaaaGcceGGDbGbaaba % daWgaaWcbaGaaeiwaaqabaGccaGGSaGaamOBaiabg2da9iaaiMdaca % GGSaGaaGymaiaaigdacaGGSaGaaGymaiaaiodacaGGSaGaaGymaiaa % isdacaGGSaaaaa!6CDE! \rlap{--} [{\rm OOC(CH}_{\rm 2} {\rm )}_{n - 2} - {\rm COO} - {\rm R}^1 \rlap{--} ]_{\rm X} ,n = 9,11,13,\rlap{--} [{\rm OOC(CH}_{\rm 2} )_{n - 2} - {\rm COO} - {\rm R}^2 \rlap{--} ]_{\rm X} ,n = 9,11,13,14, $\end{document} and \documentclass{article}\pagestyle{empty}\begin{document}$ % MathType!MTEF!2!1!+- % feaaeaart1ev0aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGabi4wayaaqa % Gaae4taiaab+eacaqGdbGaae4taiabgkHiTiaabIcacaqGdbGaaeis % amaaBaaaleaacaqGYaaabeaakiaabMcadaWgaaWcbaGaamOBaiabgk % HiTiaaisdaaeqaaOGaeyOeI0Iaae4taiaaboeacaqGpbGaae4taiab % gkHiTiaabkfadaahaaWcbeqaaiaaikdaaaGcceGGDbGbaabadaWgaa % WcbaGaaeiwaaqabaGccaGGSaGaamOBaiabg2da9iaaiMdacaGGSaGa % aGymaiaaigdacaGGSaGaaGymaiaaiodacaGGSaaaaa!5300! \rlap{--} [{\rm OOCO} - {\rm (CH}_{\rm 2} {\rm )}_{n - 4} - {\rm OCOO} - {\rm R}^2 \rlap{--} ]_{\rm X} ,n = 9,11,13, $\end{document} where \documentclass{article}\pagestyle{empty}\begin{document}$ % MathType!MTEF!2!1!+- % feaaeaart1ev0aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaaeOuamaaCa % aaleqabaGaaeymaaaakiabg2da9iabgkHiTiaaboeadaWgaaWcbaGa % aeOnaaqabaGccaqGibWaaSbaaSqaaiaabwdaaeqaaOGaeyOeI0Iaae % 4qaiaacIcacaqGdbGaaeisamaaBaaaleaacaaIZaaabeaakiaacMca % cqGH9aqpcaqGdbGaaeisaiabgkHiTiaaboeadaWgaaWcbaGaaGOnaa % qabaGccaqGibWaaSbaaSqaaiaaiwdaaeqaaOGaeyOeI0caaa!4A87! {\rm R}^{\rm 1} = - {\rm C}_{\rm 6} {\rm H}_{\rm 5} - {\rm C}({\rm CH}_3 ) = {\rm CH} - {\rm C}_6 {\rm H}_5 - $\end{document} and \documentclass{article}\pagestyle{empty}\begin{document}$ % MathType!MTEF!2!1!+- % feaaeaart1ev0aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaaeOuamaaCa % aaleqabaGaaeOmaaaakiabg2da9iaaboeadaWgaaWcbaGaaeOnaaqa % baGccaqGibWaaSbaaSqaaiaabwdaaeqaaOGaeyOeI0Iaae4qaiaacI % cacaqGdbGaaeisamaaBaaaleaacaaIZaaabeaakiaacMcacqGH9aqp % caqGobGaeyOeI0IaaeOtaiabg2da9iaacIcacaqGdbGaaeisamaaBa % aaleaacaaIZaaabeaakiaacMcacaqGdbGaeyOeI0Iaae4qamaaBaaa % leaacaaI2aaabeaakiaabIeadaWgaaWcbaGaaGynaaqabaGccqGHsi % slaaa!5042! {\rm R}^{\rm 2} = {\rm C}_{\rm 6} {\rm H}_{\rm 5} - {\rm C}({\rm CH}_3 ) = {\rm N} - {\rm N} = ({\rm CH}_3 ){\rm C} - {\rm C}_6 {\rm H}_5 - $\end{document} are prepared and their solid and liquid crystalline behaviour examined and compared to that of the corresponding homologues with n even. Evidence is given of relevant odd-even effects in the thermodynamic parameters of the clearing transition. The conclusion is drawn in favour of an anisotropic structuration also of the flexible parts of the polymer chain in the liquid crystal phase.

Notes: The thermal expansion coefficient of poly(oxy-2,6-dimethoxy-1,4-phenylene), PPOO, was measured from 150 to 500 K, using a thermomechanical analyzer connected to a computer for the data handling. Poly(oxy-2,6-dimethyl-1,4-phenylene), PPO, and some brominated poly(oxy-2,6-disubstituted-1,4-phenylene)s were studied as reference materials. The apparent glass transition temperatures of the high molar mass polymers were 456 K for PPOO and 487 K for PPO, and the changes in cubic thermal expansion coefficients at Tg were 6,01 · 10-4 K-1 for PPOO and 4,23 · 10-4 K-1 for PPO. The activation of the β-relaxation was found for PPOO at 260 K and attributed to the hindered torsional oscillations of the backbone phenylene groups. Another transition was found at 160 - 170 K and interpreted as the γ-relaxation due to the oscillatory motion of the methoxy groups. Reasons for the differences in the thermal expansion behaviour of PPOO and PPO are discussed.

Notes: The activation enthalpies for the structural relaxation of poly(oxy-2,6-dimethoxy-1,4-phenylene) and poly(oxy-2,6-dimethyl-1,4-phenylene) were determined by studying the dependence of the limiting fictive temperature on the cooling rate, using a differential scanning calorimeter (DSC) interfaced to a computer. The molar mass dependence of the activation enthalpies complied with the empirical equation, ΔH· = ΔH∞· - A/Mva, where ΔH∞· is the activation enthalpy of an infinite chain length polymer, Mv is the viscosity-average molar mass, a = 0,64, and A is a constant that depends on the free volume of the chain ends of the polymers. The values of ΔH∞· are 433 kJ/mol for poly(oxy-2,6-dimethoxy-1,4-phenylene) and 449 kJ/mol for poly(oxy-2,6-dimethyl-1,4-phenylene).

Notes: Relations between molar mass M and molar mass dependent properties E of polymers are mostly strictly valid only for monomolecular samples i: \documentclass{article}\pagestyle{empty}\begin{document}$ M_i = {\rm f (}E_i )\quad \quad \quad \quad \quad \quad (1{\rm a}) $\end{document} For polymolecular polymer samples the corresponding averages Mav and Eav must be applied: \documentclass{article}\pagestyle{empty}\begin{document}$ M_{{\rm av}} = {\rm f (}E_{{\rm av}} )\quad \quad \quad \quad \quad \quad (1{\rm b}) $\end{document} Provided the kind of average (number-, weight- or any general average) of e.g. Mav is known, the corresponding average Eav is given by. Eqs. (1a, b). This is demonstrated for the relationships of van't Hoff and Mark-Houwink, frequently used for the determination of molar masses of polymers. It is also shown that the four different relations for the expansion factor α by Flory-Stockmayer, Fixman, Ptitsyn, and by Yamakawa-Tanaka can be applied to polymolecular polymer samples (i.e. without fractionation), provided the corresponding averages[η]av and Mav from the Mark-Houwink relationship are taken for the evaluation of the parameters KΘ and B′.

Notes: In the first part of this series the individual rate constants of the radical polymerization of ethylene are reported in dependency of pressure at 405 K. By further measurements under 500 - 1750 bar and 400 - 470 K, using again the method of the rotating sector, the dependency of the rate constants on both pressure and temperature was determined. With increasing temperature the rate constant of chain growth kp as well as that of chain termination kt increases. With increasing pressure, kp increases, whereas kt decreases because of the diffusion controlled termination reaction. For the chain growth an activation energy of Ep = 37 kJ/mol and an activiation volume of Δvp≠ = -25,5 ml/mol was found. The activiation parameters of the chain termination are Et = 9,9 kJ/mol and Δvt≠ = 7 ml/mol. Based on these results and literature data the rate constants of different chain transfer reactions involved in the high pressure polymerization of ethylene and their dependency on temperature and pressure were evaluated.

Notes: Metal-2,9,16,23-tetracarboxyphthalocyanines(Mt-taPc's) [Mt = Fe(III), Co(II), Ni(II), Cu(II)] covalently bound to poly(2- or 4-vinylpyridine-co-styrene) were synthesized by Friedel-Crafts reaction of the styrene units of the copolymers with Mt-taPc tetraacid chloride. The copolymers contain about 0,3 to 14,6 mol-% Mt-Pc rings and are soluble in methanol, ethanol, and N,N-dimethylformamide. The coordination spheres around the Mt-Pc rings were characterized by electronic as well as ESR spectra and by viscosity measurements. The dimerization of Mt-taPc in the copolymers is sterically hindered by the polymer chain. The copolymer supported Fe(III)- or Co(II)-taPc's are of the five coordinate high spin type in DMF solution. One coordination site at axial position of the Mt-Pc ring may be occupied by an N atom of a pyridine group. The electronic structures of the metal atoms may be useful in catalytic reactions.

Notes: Five new copolyesters 3a - e were prepared by reacting β-(4-methoxy-3 methyl)phenylglutaconic acid dichloride (1 b) with diols 2 a - e. The polymers were characterized by IR and TG. All polymers were found to decompose in the range of ≈200 to ≈650°C.

Notes: The self-emulsifying copolymerization of unsaturated polyesters (UP) with various acrylic and methacrylic esters was studied. The structure of comonomers significantly influences the character of microgels obtained. Among these monomers the copolymerization of UP with methyl methacrylate (MMA) was investigated in detail in order to make clear the behavior of this polymerization as compared with that of styrene. The water/monomer and UP/MMA ratios were found to be the most important factors controlling the molecular weight and solution viscosity of the microgels. The relationship between M̄w and intrinsic viscosity of microgels suggests that the microgels from MMA have less compact structure than those from styrene.

Notes: To obtain a carrier polymer for pharmacologically active components, linear polyethyleneimine (LPEI) was chemically modified by reactions with acrylic acid (1a), acrylamide (1b), acrylic acid esters (1c and 1d), sodium chloroacetate, and hydrochloric acid. All product polymers 2a - 2e are soluble in water. Among these, 2a and 2e, β- and α-amino acid derivatives, respectively, show no acute toxicity in mice up to dosages of 1 g/kg i. v. Similar types of polymers 5a and 5b and a polymer containing phosphonic acid moieties (5d) derived from branched polyethyleneimine (BPEI) were prepared. 5a and 5b are also nontoxic regardless of the molecular weight of four kinds of BPEI and of the wide range of carboxylic group content in the polymer. It is suggested that the zwitterion form contributes to the nontoxic nature of β-and α-amino acid type polymers. The present results show that amino acid type polymers derived from LPEI and BPEI can be used as carrier polymers for pharmacologically active components.

Notes: The formation of charge-transfer (CT) complexes between eleven naphthalene derivatives and eight di- or trinitrobenzene derivatives in water and in water-organic solvent systems has been studied in the presence and absence of β- or γ-cyclodextrin (β- or γ-CDx), respectively. Data of UV absorption and circular dichroism (CD) clearly revealed that γ-CDx, in several cases, assists CT complex formation by accommodating both electron donor (D) and acceptor (A) molecules in its cavity simultaneously. Thus the weak CT band was intensified and even some systems in which CT complex formation was usually not observed produced CT complexes by the addition of γ-CDx. In contrast, β-CDx did not promote markedly the CT complex formation except in one case. It did promote the CT complex formation between α-naphthylacetic acid (α-NAA) and picric acid (PA), manifesting the capability of β-CDx to include two aromatic molecules. Magnetic circular dichroism (MCD) associated with the CT bands was detected for a π - π* type CT complex for the first time, but its intensity was quite weak as anticipated from theory.

Notes: Chloromethyloxirane (CMO) undergoes an asymmetric selective oligomerization with a binary catalyst system comprised of triethylaluminium and an optically active cobalt complex, N,N'-disalicylidene-(1 R)-1,2-cyclohexanediyldiaminatocobalt(II). A series of optically active oligomers obtained were isolated and characterized. Two kinds of linear oligomers were produced with respect to the end groups, namely epoxy- and halohydrin-ended oligomers. A mechanism for the selective formation of linear oligomers by the present catalyst system is proposed.

Notes: Polymerization of ethylene oxide (EO)-catalyzed by a binary system consisting of triphenyl-antimony dibromide (TPAB) and triphenylphosphine (TPP) was carried out. TPAB itself could induce the polymerization, but the addition of TPP to TPAB greatly enhances the catalytic activity. A characteristic inflection point, which appeared clearly in the time-polymerization curves, divided the polymerization into two successive steps. The preceding process is a cationic step in which an intermediate antimony dialkoxide is produced and the following a coordinated polymerization. The mean consumption of EO per catalyst at the inflection point was calculated to be 45 and was independent of the mole ratio of [TPP]/[TPAB]. It is assumed that TPP coordinates to the central antimony atom to produce an active complex salt in the second step. The effect of p-substitution of TPAB in the polymerization was also investigated; the Hammett parameters p for the first and the second polymerization step were found to be +1,7 and +1,0, respectively.

Notes: The copolymerization of methyl acrylate (MA) and isobutylene (IB) in the presence of Lewis acids (EtAlCl2, Et2AlCl, Et3Al, AlCl3, and ZnCl2) at low Lewis acid/MA mole ratio was investigated. EtAlCl2 and Et2AlCl were found to initiate the spontaneous reaction. An alternating copolymer was produced in this reaction when an excess of IB in the initial monomer feed was used. The copolymerization in the presence of Et3Al, AlCl3, and ZnCl2 did not proceed spontaneously and was initiated by dibenzoyl peroxide (BPO). In this case MA-rich copolymers are formed even in systems containing a large excess of IB in the monomer feed. The addition of BPO to systems containing ethylaluminium chlorides strongly diminishes the tendency towards alternating propagation. It was concluded that the mode of initiation has a significant influence on the copolymer composition. The alternating copolymerization by EtAlCl2 was studied in detail in order to determine the influence of the catalyst concentration, monomer feed ratio, reaction temperature and time on the monomer conversion, copolymer composition, molecular weight and tacticity.

Notes: N-Vinylcarbazole (NVC) is polymerised in the presence of pyridine at 60°C by using azodiisobutyronitrile (AIBN) and benzoyl peroxide (Bz2O2) as initiators and the results are compared with those obtained when benzene is used as the solvent. In the AIBN-initiated system using pyridine as the solvent the rates of polymerisation follow an usual linear relationship with respect to monomer concentration and a square root dependence with respect to the initiator concentration. In the Bz2O2-initiated system, however, deviations from these ideal behaviours are observed when benzene and pyridine, respectively, are used as the solvent. Initiation occurs through the complexation of the monomer with Bz2O2 and degradative transfer is thought to be mainly responsible for this unusual kinetic behaviour.

Notes: The electron transfer process in the microdomain of a polyion complex composed of poly(sodium styrenesulfonate), (syst. name: poly[sodium 1-(4-sulfonatophenyl)ethylene]), and poly(alkylene viologen)s 1 with 3 to 10 methylene groups between two adjacent viologen units was analyzed by means of voltammetry with a rotating disc electrode. Although the stability of 1 on the graphite electrode was improved by the formation of a polyion complex with poly(sodium styrenesulfonate), a smaller surface charge was observed in the polyion complex as compared with the electrode coated with poly(alkylene viologen) alone. Since the migration of the counter ion was clarified to be indispensable for the electron transfer in this case, the microdomain of polyion complexes should be formed by tightly-shrunk polyelectrolyte chains. Furthermore, the electron transfer in the microdomain of the polyion complex is hardly detected, when the electrode is coated with an excess of the complex. The electron transfer strongly depended on the average distance between two adjacent redox sites in the matrix. These matrixes were suggested to be controlled by the subtle balance of hydrophobicity and charge density of 1.

Notes: The photoinduced formation of oligomers in single crystals of 2,5-distyrylpyrazine (DSP) was investigated by X-ray and electron diffraction techniques and also by gel permeation chromatography (GPC). The DSP crystals were characterized for the presence and nature of dislocations by dark-field images and etch-pit studies. Small angle grain boundaries were identified to be the prominent feature, but in general the crystals were highly perfect. A correlation between the sites of the defects and the formation of the photoproduct could not be detected. The oligomers formed in a solid-solution under appropriate irradiation conditions. Thus, DSP oligomer of number average degree of polymerization P̄n = 3,2 in macroscopic single crystal texture was obtained for the first time using a laser light source at 478 nm. Deterioration of the single crystal texture of DSP usually observed during photopolymerization is explained as being caused by inhomogeneous light distribution which in turn causes an inhomogeneous product distribution with accumulation of large strain fields. These can be made visible by the multiplication of etch pits. Phase separation between oligomer and polymer is observed on further irradiation of the oligomer single crystals. The oligomer phase seems to play the role of an intermediate in the photopolymerization of DSP at wavelengths λ 〈 400 nm. The molecular weight distribution of the oligomers was studied by GPC. The data are only compatible with the assumption that the rate constant of dimerization is higher than that for the addition of a monomer to an already existing oligomer.

Notes: Active β-alanine esters having dipeptide groups, which are capable of forming hydrogen bonds between the side chains, were prepared in the form of hydrogen chloride salts. The polycondensation of these salts was studied in non-polar solvents, in the presence of triethylamine. In the case of the ester with β-alanyl-β-alanine as dipeptide moiety, the polycondensation proceeded smoothly in chloroform solution. To explain the characteristic feature of the polycondensation, an ordered aggregation of the ester molecules is assumed to play an important role. The ester with glycylglycine as dipeptide moiety, however, did not undergo a polycondensation.

Notes: Conformanational energies of various oligo (oxyethylene) isomers were calculated by the empirical force field method, and statistical mechanics calculations of the chain dimensions and the dipole moments were carried out. The results are seriously different from those obtained for poly (oxymethylene). Although the first-order steric interactions in POE are of the same order of magnitude as those in n-alkane chains, the second-order interactions are significantly different. The second-order interactions arising from rotations around two consecutive bonds of OCH2CH2OCH2 in g± g∓ conformation have greatly reduced steric repulsions. It was found that the reduced second-order interaction plays an important role in the configurationdependent properties of POE. The agreement of the calculated values for the unperturbed dimensions and the temperature coefficients obtained from the force field method with experimentally observed ones is fairly good.

Notes: Polymerization of ethylene initiated in naphta solution by Zr(CH2C6H5)4 at 200°C under high purity conditions showed a cocatalytic effect of water with a maximum rate for a mole ratio H2O/Zr close to 0,1. No activity was observed for the hypothetical compound (C6H5CH2)3ZrOZr(CH2C6H5)3. Ethylene polymerization was also initiated with supported catalysts obtained by reaction of Zr(CH2C6H5)4 with silicium oxide or pre-dried aluminium oxide with an increase of activity (by a factor of 5). The resulting polyethylenes were found to be virtually linear with 1,5 CH3 groups for 1000 C atoms and with melting points of 134 - 136,5°C. They have high molecular weights with very broad distribution. These results were interpreted by a mechanism involving Ziegler-like active centers.

Notes: Binding of mono-, di-, and oligosaccharides by amide linkage to polymers carrying carboxylic or amino groups was studied with synthetic polymers (poly(acrylic acid), poly(vinylamine)) and polysaccharide derivatives (e.g. chitosan). Suitable methods are described which allow a variation of the number and lenght of the attached saccharide branches. In the absence of salt, all products with a degree of substitution (DS) 〈 1 show polyelectrolyte behaviour. Compared with the unsubstituted polyelectrolytes, for the branched polymers a substantial increase of the viscosity was observed within a certain range of branch density. In the case of glucose side chains, the maximum viscosity was found near DS = 0,1. In the case of maltose side chains, this maximum of the viscosity occurred at higher DS. A similar but smaller increase in the viscosity was observed in 0,1 M NaCl solution. The results are explained by a shielding of the backbone charges from the counterions and by an additional chain stiffening effect resulting from hydrogen bonds, i.e., ring formation between the amide linkage and adjacent free carboxylic or amino groups.

Notes: Derivatives of poly(methacrylic acid) with mesogenic sidegroups are aggregated in solution. Through structural changes which also take place in the solid state, the fraction of the aggregates increases with storage time. The formation of aggregates depends on temperature and occurs relatively slowly. In solution, the degree of aggregation strongly depends on the solvent. This aggregation leads to relatively high tacticity in products obtained by radical initiated polymerisations.

Notes: The solvent influence on two- phase structures resulting from drying films of segmented polyetherurethanes of different hard segment contents and molecular weights was investigated by infrared dichroism measurements of the orientational behaviour of the hard segments. A low density of physical crosslinking and/or minor association in solution leads to a lamellae structure resulting in an inhomogeneous distribution of stress at elongation. The formation of lamellae is impeded, if the solution shows pronounced formation of associates. Destruction of the lamellae can be monitored by studying the orientational behaviour for repeated deformations and by means of orientation-extension-hysteresis experiments. Stress-strain diagrams exhibit no contradictions to the discussed structural transformations by the influence of different solvents.