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601.
602.
Takahide Mizawa Katsuhiko Takenaka Tomoo Shiomi 《Journal of polymer science. Part A, Polymer chemistry》1999,37(17):3464-3472
In order to synthesize end-functionalized polymers with conjugated dienyl groups, living polymeric anions of polystyrene and polyisoprene were allowed to react with 5-bromo-1,3-pentadiene, 1, and 7-bromo-1,3-heptadiene, 2. The reaction of polystyryl anion and/or polyisoprenyl anion with 1 gave polymers whose end-functionalities were 65–80% regardless of the reaction conditions. On the other hand, almost quantitative functionalization was achieved when a large excess amount of 2 was used as a terminator. When 1,1-diphenylalkyl anion and enolate anion derived from t-butyl methacrylate were used, the degree of end-functionality were 70–80% at best. The resulting end-functionalized polymers were characterized by size exclusion chromatography (SEC), 1H and 13C-NMR and thin layer chromatography coupled with a flame ionization detector (TLC-FID). © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 3464–3472, 1999 相似文献
603.
Yoshinori Kamiya Yasutoshi Naito Keishin Mizoguchi Katsuhiko Terada Johann Moreau 《Journal of Polymer Science.Polymer Physics》1997,35(7):1049-1053
The Flory–Huggins interaction parameters χ for 23 gases (He, Ne, Ar, Kr, Xe, H2, N2, O2, N2O, CO2, CH4, C2H4, C2H6, C3H6, C3H8, 1,3-C4H6, four C4H8's, n-C4H10, iso-C4H10, and n-C5H12) in five rubbery polymers (1,2-polybutadiene (PB), poly(ethylene-co-vinyl acetate)) (EVAc), polyethylene (PE), polypropylene (PP), and poly(dimethyl siloxane) (PDMS) were determined from either literature data on Henry's law coefficient and partial molar volume or those on sorptive dilation for each polymer/gas system. Values of χ for the gases increased in the order of PDMS < PP ≡ PB < EVAc ≡ PE. Among the gases except He and H2 whose χ values are not reliable, Ne and Xe have respectively the highest and the lowest values of χ for the polyolefins. The χ values of the hydrocarbons were compared together with previously reported χ values of n-alkanes C3-C10. The dependencies of χ upon concentration and temperature were discussed on the basis of the literature data. © 1997 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 35 : 1049–1053, 1997 相似文献
604.
Kanji Suyama Katsuhiko Ito Masahiro Tsunooka 《Journal of polymer science. Part A, Polymer chemistry》1996,34(11):2181-2187
Photochemical reactions of copolymers of O-acryloyl acetophenone oxime (AAPO) and phenyl vinyl ketone (PVK) in the solid phase were investigated. The decrease of molecular weight of these copolymers in the photolysis was limited compared to that of PVK homopolymer. Results of IR and elemental analyses showed that pendant acyloxyimino (AOI) groups were phototransformed into the pendant amino groups. This behavior suggests that PVK units in this copolymer worked as a sensitizer for the photolysis of AOI groups. The energy transfer from PVK units to AOI groups was confirmed to proceed via an excited triplet state by the quenching study of phosphorescence of a PVK homopolymer by a model compound, O-cyclohexanecarbonyl acetophenone oxime. Dissolution alteration of AAPO copolymers before and after irradiation was also investigated. © 1996 John Wiley & Sons, Inc. 相似文献
605.
Chikara Tsutsumi Nobuki Hayase Katsuhiko Nakagawa Suminori Tanaka Yasushi Miyahara 《Macromolecular Symposia》2003,197(1):431-442
Biodegradable polyesters, poly(butylene succinate adipate) (PBSA), poly(butylene succinate) (PBS), poly(ethylene succinate) (PES), poly(butylene succinate)/poly(caprolactone) blend (HB02B) and poly(butylene adipate terephthalate) (PBAT), were evaluated about degradability for enzymatic degradation by lipases and chemical degradation in sodium hydroxide solution. In enzymatic degradation, PBSA was the most degradable by lipase PS, on the other hand, PBAT containing aromatic ring was little degraded by eleven kinds of lipases. In 1N NaOH solution, degradation rate of PES with ethylene unit was extremely fast, in comparison with other polyesters. Interestingly the degradation rate of PBSA in enzymatic degradation by lipase PS was faster than in chemical degradation. 相似文献
606.
607.