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  • 1
    Electronic Resource
    Electronic Resource
    Radical reactivity of α-trifluoromethylstyrene (1988)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 89-98 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: α-Trifluoromethylstyrene (TFMST) does not undergo radical homopolymerization with azobis(isobutyronitrile) (AIBN) in bulk at 60°:C. Low-temperature initiation was not effective either. Radical copolymerization of TFMST (M2) with styrene (ST, M1) has yielded monomer reactivity ratios as follows: r1 =: 0.60 and r2 =: 0.00. It has been found that the cyclohexyl radical generated by reaction of cyclohexylmercuric chloride with sodium borohydride adds to the β-carbon of TFMST 7.5 times faster than that of ST. Combination of the copolymerization analysis and the “mercury method” has allowed us to estimate Alfrey-Price Q and e parameters for TFMST to be 0.43 and 0.90, respectively. Thus, due to the strongly electron-withdrawing effect of the trifluoromethyl group, this styrene is highly electron deficient. In spite of the favorable electronic effect, however, the ceiling temperature appears very low, presumably due to the steric hindrance.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1988.080260109
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  • 2
    Electronic Resource
    Electronic Resource
    Chain scission efficiency and reactive-ion etch resistance of alternating copolymers of styrene and olefins trisubstituted or tetrasubstituted with electron-withdrawing groups (1986)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 955-964 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Alternating copolymers of styrene (St) with electron-deficient olefins trisubstituted or tetrasubstituted with cyano and carboalkoxy groups have been subjected to 60Co γ-radiolysis together with a series of copolymers of methyl methacrylate (MMA) and St. The chain scission susceptibility Gs - Gx determined by membrane osmometry drastically decreases as St is incorporated in poly(methyl methacrylate) (PMMA). Whereas the alternating St-MMA copolymer is slightly crosslinked upon irradiation, an alternating copolymer of St with diethyl 2-cyano-1,1-ethylenedicarboxylate maintains a fairly high degradation sensitivity (Gs - Gx = 1.2). The reactive-ion etch rates were determined for the series of polymers in CF4/O2 (92/8). The etch resistance is significantly increased by introduction of St units in PMMA, and the highly substituted alternating copolymer etches as slowly as the MMA(50) - St(50) copolymers. Thus the alternating copolymer of NCCH=C(CO2Et)2 with St behaves like PMMA when exposed to high-energy radiation but is comparable to PSt in plasma environments.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1986.080240513
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  • 3
    Electronic Resource
    Electronic Resource
    Thermal deesterification and decarboxylation of alternating copolymers of styrene with β-substituted t-butyl α-cyanoacrylates (1989)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 27 (1989), S. 2871-2881 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Alternating copolymers of styrene with β-carboalkoxy-substituted t-butyl α-cyanoacrylates undergo facile deesterification at 150-190°C, about 60°C below the deprotection temperature of poly(t-butyl methacrylate), and decarboxylation at 170-200°C. When the β-substituent is a methyl ester, the two events are clearly separated, with the deesterification occurring at a maximum rate at 165°C and decarboxylation at 193°C. Anhydride formation is negligible in this case. The copolymer with t-butyl cyanofumarate exhibits simultaneous deesterification and decarboxylation events at 180°C with concomitant minor dehydration.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1989.080270904
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  • 4
    Electronic Resource
    Electronic Resource
    Solid-state thermolysis of poly(p-t-butoxycarbonyloxystyrene) catalyzed by polymeric phenol: Effect of phase separation (1986)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 2971-2980 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Thermolysis of poly(p-t-butoxycarbonyloxystyrene) (PBOCST) catalyzed by polymeric phenol in the solid state is very much dependent on the extent of phase separation. Poly(p-hydroxystyrene) (PHOST, a thermolysis product of PBOCST) is not miscible with PBOCST. Therefore, this phenolic resin can not effectively catalyze the solid-state thermolysis reaction when simply blended with PBOCST. However, if the phenolic functionality is forced to be in the vicinity of the t-butoxycarbonyl (tBOC) group, the thermolysis takes place facilely at 130°C. The effect of casting solvent on thermolysis in PBOCST/Varcum films is also discussed.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1986.080241124
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  • 5
    Electronic Resource
    Electronic Resource
    Reactivities of methacrylate derivatives in radical polymerization as evaluated by mercury method (1988)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 2395-2404 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Reactivities of methyl methacrylate derivatives bearing substituents on the ester methyl group have been investigated by competitively adding a cyclohexyl radical generated by a reaction of cyclohexylmercuric chloride with sodium borohydride (mercury method) to these substituted methacrylates and methyl methacrylate or styrene. The relative rate constants of the cyclohexyl radical addition have been found to be nicely correlated with parameters such as Traft α* constants of alkyl esters, Q-e values, lowest unoccupied molecular orbital energies, β-carbon chemical shifts, and relative reactivities toward a polystyryl radical, indicating that the mercury method is a simple and useful technique for evaluation of the relationship between structure and reactivity of vinyl monomers in their radical polymerization, even when the structural modification is small.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1988.080260912
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  • 6
    Electronic Resource
    Electronic Resource
    13C chemical shift non-equivalence in methylene carbons of monosubstituted cyclohexanes (1989)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 27 (1989), S. 273-276 
    Details
    ISSN: 0749-1581
    Keywords: Anisochronism ; Magnetic non-equivalence ; Cyclohexyl adducts ; Mercury method ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Monosubstituted cyclohexanes were synthesized by addition of a cyclohexyl radical to olefins bearing different substituents at the α-position. Six distinct methylene 13C resonances were observed, indicating that the methylene carbons located at the 2 and 6 positions and at the 3 and 5 positions are not magnetically equivalent. This magnetic non-equivalence (anisochronism) observed in the monosubstituted cyclohexanes is due to the introduction of an asymmetric center β to the prochiral C-1 ring carbon.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1260270315
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