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  • 1
    Electronic Resource
    Electronic Resource
    Synthesis and biodegradation of poly(γ-butyrolactone-co-l-lactide) (1996)
    Springer
    Journal of polymers and the environment 4 (1996), S. 205-211 
    Details
    ISSN: 1572-8900
    Keywords: γ-Butyrolactone ; l-lactide ; biodegradable polymer ; hydrolysis ; ring-opening polymerization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Energy, Environment Protection, Nuclear Power Engineering , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Biodegradable polyesters were synthesized by ring-opening copolymerization of γ-butyrolactone (BL) and its derivatives withl-lactide (LLA). Although tetraphenyl tin was the main catalyst used, other organometallic catalysts were used as well.1H and13C NMR spectra showed that poly(BL-co-LLA)s were statistical and that their number-average molecular weights were as high as 7×104. The maximum BL content obtained from copolymerization BL/LLA was around 17%. TheT m andT g values of the copolymers showed a gradual depression with an increase in BL content. NoT m was obtained for the copolymers containing more than 13 mol% BL. The biodegradability of the copolyesters was evaluated by enzymatic hydrolysis and nonenzymatic hydrolysis tests. The enzymatic hydrolysis was carried out at 37°C for 24 h using lipases fromRhizopus arrhizus andR. delemar. Hydrolyses by both lipases showed that an increase in BL content of the copolymer resulted in enhanced biodegradability. Nonenzymatic accelerated hydrolysis of copolymers at 70°C was found to increase proportionally to their exposure time. The hydrolysis rate of these copolymers was considerably faster than that of PLLA. The higher hydrolyzability was recorded for the BL-rich copolymers. The copolymerization of γ-methyl-γ-butyrolactone (MBL) or γ-ethyl-γ-butyrolactone (EBL) with LLA resulted in relatively LA-rich copolymers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02067454
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  • 2
    Electronic Resource
    Electronic Resource
    Properties and biodegradability of chain-extended copoly(succinic anhydride/ethylene oxide) (1996)
    Springer
    Journal of polymers and the environment 4 (1996), S. 225-233 
    Details
    ISSN: 1572-8900
    Keywords: Copolyesterether ; succinic anhydride ; chain-extension reaction ; biodegradation ; activated sludge
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Energy, Environment Protection, Nuclear Power Engineering , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Chain-extension reactions were carried out using titanium-iso-propoxide (TIP) as a catalyst for a series of polyesters or copolyesterethers with low molecular weights (M n =1500–10,000) synthesized by the ring-opening copolymerization of succinic anhydride (SA) with ethylene oxide (EO). The copolymers having aM n from 25,000 to 50,000 of different properties were obtained. Both the melting point (T m ) and the fusion heat (δH), which indicate the crystallinity of the copolymers, rose with an increase in SA content in the copolymers. Semitransparent films were prepared by compression molding of the copolymers. The biodegradation of the copolymer films was evaluated by enzymatic hydrolysis by lipases and by an aerobic gas evolution test in standard activated sludge. The hydrolyzability of these copolymers by three kinds of lipases was affected by their copolymer composition SA/EO, form, andM n . The copolyesterether (SA/EO=43/57,M n =48,900) was more easily biodegraded by standard activated sludge compared to the polyester (SA/EO=47/53,M n =36,300).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02070691
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  • 3
    Electronic Resource
    Electronic Resource
    Sensory evaluation of carpet cleaner containing essential oil and the effect on mites (1998)
    Springer
    Journal of wood science 44 (1998), S. 90-97 
    Details
    ISSN: 1611-4663
    Keywords: Sensory evaluation ; Essential oil ; House dust mite ; Carpet cleaner
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract We prepared carpet cleaners containing three wood oils extracted from Thujopsis dolabrata Sieb. et Zucc. var. hondai Makino, Chamaecyparis obtusa Endl., and Chamaecyparis taiwanensis Masamune et Suzuki and studied their effects on mites and perfumerists' impressions. The oil concentrations were set at 0.1%, 0.2%, 0.4%, 0.8%, and 1.6%. The effects on Dermatophagoides pteronyssinus Trouessart were investigated. The sensory evaluations were conducted by seven male perfumerists using the SD method and they were asked to describe freely their impressions of the scents. These results showed that: (1) all three types of wood oil had a significant effect on making D. pteronyssinus inactive at 0.1% concentration; and (2) the wood oil of T. dolabrata evoked refreshing, natural, rich, and intellectual feelings; C. obtusa oil evoked vivacious, rich, and intellectual feelings; and C. taiwanensis evoked refreshing, natural, rich, rough, masculine feelings. According to the test subjects, T. dolabrata evoked “woody” and “earthy” impressions; C. obtusa evoked “woody,” “citrus,” and “pine-resin” impressions; and C. taiwanensis evoked “woody,” “citrus,” and “medical” impressions. Many issues remain to be investigated, but the inclusion of wood oil in carpet cleaners offered both good mite control and a pleasant aroma to humans. This study suggests a new potential for using these wood oils.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00526251
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  • 4
    Electronic Resource
    Electronic Resource
    Synthesis and properties of biodegradable copolyesteramides: Nylon 6,6/∊-caprolactone copolymers, 1 (1994)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 222 (1994), S. 111-123 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Eine Reihe von Copolyesteramiden mit Molekulargewichten zwischen 1000 und 7000 (GPC, NMR) wurden aus Adipinsäure/1,6-Hexandiamin/∊-Caprolacton bzw. Nylon 6,6-Salz/∊-Caprolacton hergestellt. Die thermischen Eigenschaften der synthetisierten Polymeren (Glasübergangs-, Schmelz-, und Zersetzungstemperaturen, Schmelzenthalpien) wurden durch DSC- und TGA-Messungen bestimmt und in Bezug auf das Comonomerverhältnis in der Ausgangsmischung diskutiert. Die Übereinstimmung der Copolymerzusammensetzung mit dem Ausgangscomonomerverhältnis wurde mit FT-IR- und NMR-Spektroskopie untersucht. Die Bioabbaubarkeit der Copolyesteramide wurde durch enzymatische Hydrolyse geprüft.
    Notes: A series of copolyesteramides based on adipic acid/1,6-hexane diamine/∊-caprolactone and Nylon 6,6 salt/∊-caprolactone were synthesized. Their molecular weights, determined by gel permeation chromatography and NMR spectroscopy, were found to lie within the range from 1000 up to 7000. Their thermal properties (glass transitions, melting points and heats of melting, and decomposition temperatures) were recorded with diferential scanning calorimetry and thermogravimetry, respectively, and correlated to the comonomer feed composition. The FT-IR and NMR spectra were also recorded in order to confirm the composition of the copolyesteramides and to compare them with that of the comonomer feed. The biodegradability of the synthesized copolymers was tested by enzymatic hydrolysis.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1994.052220109
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  • 5
    Electronic Resource
    Electronic Resource
    A note on the crack behavior in brittle materials under the double cantilever beam cleavage at constant strain rate (1971)
    Springer
    International journal of fracture 7 (1971), S. 447-450 
    Details
    ISSN: 1573-2673
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Résumé Pour mesurer l'énergie de surface et la vitesse de fissuration dans les matériaux fragiles, on a appliqué la technique, utilisée par plusieurs chercheurs, de la mise en clivage d'une éprouvette en forme de double poutre cantilever. Les auteurs ont analysé le comportement de fissures dans ce type d'éprouvettes à vitesse de déformation constante.
    Abstract: Zusammenfassung Das Doppelkantileverproben-Spaltverfahren (DCB), welches von verschiedenen Verfassern (1–5) entwickelt worden ist, wurde für die Messung der Oberflächenenergie [1, 4–8] und der Rißausbreitungsgeschwindigkeit [3,9] in spröden Materialien angewandt. Die Verfasser untersuchten das Rissverhalten in DCB-Proben bei konstanter Verformungsgeschwindigkeit.
    Notes: Abstract The double cantilever beam (DCB) cleavage technique developed by many investigators(1–5) has been applied for measuring the surface energy 0,4–8) and the crack velocity(3,9) in brittle materials. The authors investigated the crack behavior in the DCB cleavage specimen at constant strain rate.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00189114
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  • 6
    Electronic Resource
    Electronic Resource
    A note on the resistance to brittle fracture in various ceramic materials (1969)
    Springer
    International journal of fracture 5 (1969), S. 81-82 
    Details
    ISSN: 1573-2673
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The square of the ratio of the abraded bending strength, σd, to the unabraded bending strength, σ, is proposed as a measure of the resistance to crack propagation in ceramic materials. Data for various porcelains, glass-ceramics, and glasses showed that σd is essentially constant and that (σd/σ)2 decreased rapidly with increase of the unabraded strength.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00189943
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  • 7
    Electronic Resource
    Electronic Resource
    Novel biodegradable copolyamides based on adipic acid, isophorone diamine and α-amino acids, 3Part 2, cf.13.. Synthesis, study of properties and evaluation of their biodegradability for food packaging applications (1994)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 221 (1994), S. 67-90 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Neuartige biologisch abbaubare Copolyamide wurden durch Schmelzkondensation hergestellt. Durch den Einbau von α-Aminosäuren wurden statistische Copolymere erhalten, die zwar erhöhte Glasübergangstemperaturen, aber geringere Zugfestigkeiten und eine geringere alkalische Hydrolysebeständigkeit aufweisen, was aus GPC-Messungen hervorgeht. Die amorphe Struktur dieser neuen Copolyamide wurde durch Röntgenweitwinkelstreuung und Differentialthermoanalyse bestätigt. Durch FT-IR-Spektroskopie wurde das Vorhandensein der Aminosäuresegmente belegt. Diese neuartigen biologisch abbaubaren Copolyamide könnten für sich alleine oder auch als Bestandteil von Composites Anwendung finden, z. B. als Nahtmaterial bei der Fixierung von Implantaten.
    Notes: Novel biodegradable copolyamides were synthesized by melt polycondensation. Statistical copolymers were produced by the incorporation of α-amino acids showing a gradual increase in their Tg but a decrease in their tensile strength followed by higher susceptibility to alkali hydrolysis which was confirmed with GPC measurements. The amorphous nature of these novel copolyamides was confirmed with the aid of wide-angle X-ray diffraction patterns and differential thermal analysis. FT-IR spectra of the copolymers confirmed the existence of the amino acid moiety. These novel biodegradable copolyamides are expected to find application either on their own in the fields of food packaging and agriculture (disposable plastics) or as a part of composites, as sutures for fixation of macroscopic implants.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1994.052210107
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  • 8
    Electronic Resource
    Electronic Resource
    New copolyamides based on adipic acid, aliphatic diamines and amino acids: Synthesis, characterization and biodegradability, 5Part 4: cf. ref. 59 (1995)
    Weinheim : Wiley-Blackwell
    Macromolecular Chemistry and Physics 196 (1995), S. 1129-1151 
    Details
    ISSN: 1022-1352
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Novel series of biodegradable copolyamides were synthesized via melt copolymerization. The statistical copolymides were produced by reaction of the salt of adipic acid (AA) and bis(para-aminocyclohexyl)methane (PACM) or isophoronediamine (IPD)/α-amino acids at 250°C. Elemental analyses, density, viscosity, differential thermal analysis (DTA) and gelpermeation chromatography (GPC) measurements and FT-IR spectroscopy were employed for the characterization of these copolyamides. The semicrystalline (AA/PACM/α-amino acids) or amorphous (AA/IPD/α-amino acids) nature of these copolyamides was shown with DTA and wide angle X-ray diffraction patterns. Several methods were used in order to investigate and assess their biodegradability such as alkaline hydrolysis (10% w/v NaOH, 80°C), burial in soil (microbial and bacterial attack) and enzymatic hydrolysis (α-trypsin and α-chymotrypsin). The degradation of the copolyamides was evaluated with the aid of GPC and DTA measurements and correlated to the α-amino acid content. These copolyamides could eventually find applications in the field of food packaging and agriculture (disposable plastics) and medicine (sutures).
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1995.021960414
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  • 9
    Electronic Resource
    Electronic Resource
    Composites of novel biodegradable copolyamides based on adipic acid, 1,6-hexane diamine, and L-glycine with short E-glass fibers. II. Preparation and properties (1995)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 56 (1995), S. 1045-1058 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: A study was conducted on the preparation of composite materials based on novel biodegradable copolyamides reinforced with E glass fibers by using the hand lay-up technique. Differential thermal analysis (DTA) and wide angle x-ray diffraction patterns were employed for investigating the effect of transcrystallinity on percentage crystallinity of composites. The thermal properties of composites (Tg and Tm) were determined with DTA and dynamic mechanical thermal analyzer (DMTA) measurements. Void fractions were evaluated from density measurements and correlated to glass fiber contents. The stress-strain curves and compression strength measurements were recorded and correlated with the glass fiber content, void content, and the percentage amino acid content of the copolymers. Although high α-amino acid contents caused a decrease in Tg and Tm and the tensile strength of copolyamides, the introduction of glass fibers was found to counterbalance this effect by initiating an increase in the percentage crystallinity. © 1995 John Wiley & Sons, Inc.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1995.070560904
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  • 10
    Electronic Resource
    Electronic Resource
    Synthesis of a new biodegradable copolyesteramide: poly(L-lactic acid-co-ε-caprolactam) (1998)
    Weinheim : Wiley-Blackwell
    Macromolecular Chemistry and Physics 199 (1998), S. 2445-2451 
    Details
    ISSN: 1022-1352
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Novel copolyesteramides were synthesized by reacting L-lactic acid (LLA) with ε-caprolactam (CLM) in the presence of Fe, Sn or Zn powder as a catalyst. The molecular weight of the copolymers was 3.7 × 103 when using tin as a catalyst. For the purpose of increasing the molecular weight of the copolymer, azeotropic removal of water from the reaction mixture was performed; the molecular weight increased to 8.4 × 103. The biodegradability of the copolymers was evaluated by using a standard activated sludge. One of the copolyesteramides (mole ratio LLA/CLM = 45/55, Mn = 8.4 × 103) was degraded up to 50% after 33 d in contact with an activated sludge.
    Additional Material: 5 Ill.
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