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31.
Tadatomi Nishikubo Takashi Iizawa Akira Takahashi Tsutomu Shimokawa 《Journal of polymer science. Part A, Polymer chemistry》1990,28(1):105-117
Poly[4-(4-nitrobenzyloxy)styrene] was synthesized with a high degree of etherification by the reaction of poly(4-hydroxystyrene) (PHST) with p-bromomethylnitrobenzene (p-BMNB) using 1,8-diazabicyclo-[5,4,0]-7-undecene (DBU) in hexamethylphosphoramide (HMPA). Poly[4-(3-nitrobenzyloxy)styrene] and poly[4-(2-nitrobenzyloxy)styrene] were also prepared with a high degree of etherification by the corresponding reaction with m- or o-BMNBs. However, the degrees of etherification of PHST with these BMNBs were relatively low when the reactions were carried out in other aprotic polar solvents such as DMF, DMSO, and N-methyl-2-pyrrolidone. On the other hand, poly(4-introbenzyl methacrylate) (PPNBMA), poly(3-nitrobenzyl methacrylate) (PMNBMA), and poly(2-nitrobenzyl methacrylate) (PONBMA) were synthesized with a high degree of esterification by the reaction of poly(methacrylic acid) with the corresponding BMNBs using DBU in DMSO at 30°C. The photochemical properties of the resulting poly(nitrobenzyl methacrylate)s were examined, and it was found that the rates of photodecomposition of PPNBMA and PMNBMA were promoted by the addition of tributylamine and trifluoromethanesulfonic acid, respectively. However, the rate of photodecomposition of PONBMA was not affected by addition of the base or the acid. 相似文献
32.
Bao‐Quan Chen Atsushi Kameyama Tadatomi Nishikubo 《Journal of polymer science. Part A, Polymer chemistry》1999,37(7):1009-1016
The polyaddition of bisphenol A diglycidyl ether with bis[4‐(P,P‐diphenylphosphinyloxy)phenyl] sulfone catalyzed by quaternary onium salt, such as tetrabutylammonium chloride afforded a new phosphorus‐containing polyether with good solubility in common organic solvents. Having studied various factors affecting the reaction, such as temperature, catalyst concentration, reaction time, etc., an appropriate polyaddition condition was suggested as using 5 mol % of suitable quaternary ammonium or phosphonium salt in polar solvent at 150°C within 25 h in an ampule for producing high molecular weight polymer. A number of polyethers bearing pendent phosphinate ester groups from the polyaddition of certain bis(epoxide)s and bis(phosphinate)s were synthesized under the above condition and characterized by GPC, IR, and NMR. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 1009–1016, 1999 相似文献
33.
Synthesis and thermal crosslinking reaction of polymers containing pendant carboxyl and epoxy groups
Tsutomu Shimokawa Yuichi Shinmoto Atsushi Kameyama Tadatomi Nishikubo 《Journal of polymer science. Part A, Polymer chemistry》1996,34(10):1951-1957
Polymers containing both pendant carboxyl and epoxy groups were synthesized by the radical copolymerization of p-vinylbenzyl glycidyl ether (VBGE) and itaconic acid monomethyl ester (IAME). The copolymerization proceeded smoothly under various conditions, and polymer soluble in 1,4-dioxane with no gel fraction was obtained. However, the carboxyl-epoxy addition reaction between VBGE and IAME was observed, when DMSO or DMF were used as polymerization solvents. The IR and 1H-NMR spectrum of copolymers of VBGE and IAME showed the corresponding structure. The thermal crosslinking reaction of the resulting copolymers was examined under various conditions. Tetrabutylammonium bromide (TBAB) showed catalytic activity for the reaction. However, a 100% gel fraction of polymer was achieved after only 15 min without any catalyst, when the crosslinking reaction was performed at 150°C. © 1996 John Wiley & Sons, Inc. 相似文献
34.
Tadatomi Nishikubo Atsushi Kameyama Youji Yamada Yuichi Yoshida 《Journal of polymer science. Part A, Polymer chemistry》1996,34(17):3531-3537
A convenient esterification reaction of poly(methacrylic acid) (PMAA) with certain alkyl halides was performed using 1,8-diazabicyclo-[5.4.0]-7-undecene (DBU) as a base in aqueous solution or in water. The esterification reaction of PMAA with propargyl bromide (PB) proceeded very smoothly and quantitatively at 30°C to give corresponding poly(propargyl methacrylate), although the rate of the reaction decreased with increasing water. The reaction of PMAA with benzyl bromide, o-nitrobenzyl bromide, and p-nitrobenzyl bromide gave corresponding poly(methacrylic ester) using DBU under suitable reaction conditions in water. The esterification reactions of PMAA with PB were carried out using certain organic bases such as triethylamine, 4(N,N-dimethylamino)pyridine and pyridine. Inorganic bases such as sodium carbonate, sodium hydroxide, potassium carbonate, and potassium hydroxide were also tried under the same conditions as with DBU. However, the degrees of estrification with all these bases was much lower than that with DBU. © 1996 John Wiley & Sons, Inc. 相似文献
35.
Katsumi Inomata Shigeo Kawasaki Atsushi Kameyama Tadatomi Nishikubo 《Journal of polymer science. Part A, Polymer chemistry》2001,39(4):530-538
Novel multifunctional photopolymers with both pendant epoxy groups and phenacyl ester groups were synthesized by the one‐pot method for the reaction of poly(methacrylic acid) with epibromohydrin; this was followed by a reaction with phenacylbromide with 1,8‐diazabicyclo‐[5.4.0]undecene‐7 as a condensation reagent. These esterification reactions proceeded smoothly and quantitatively under mild conditions. Moreover, the photochemical reactions of the resulting polymers were evaluated by UV and IR spectroscopy. The pendant phenacyl ester groups were photocleaved to give corresponding carboxyl groups, and then the produced carboxyl groups reacted with pendant epoxy groups. Furthermore, the baking process promoted a crosslinking reaction because of the addition reaction of epoxy groups with carboxyl groups after irradiation. It was also proven that the photochemical reactivity of the resulting polymers was affected by the structure of the phenacyl ester group. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 530–538, 2001 相似文献
36.
Nobuhito Ito Hiroto Kudo Atsushi Kameyama Tadatomi Nishikubo Tetsuo Anada 《Journal of polymer science. Part A, Polymer chemistry》2003,41(1):213-222
The synthesis and optical properties of polyesters with pendant fluorinated phenoxy groups were examined. The polyaddition of bisphenol AF diglycidyl ether ( 1 ) with fluorine‐containing terephtalates ( 2a–f ) was carried out with tetrabutylphosphonium chloride (TBPC) as the catalyst in chlorobenzene to afford the corresponding polyesters with number‐average molecular weights (Mn's) ranging from 15,200 to 30,000 in 88–96% yields. Furthermore, the polyaddition of 1 with isophthalate 2g and phthalate 2h also produced high‐molecular‐weight polyesters with Mn's = 22,700 and 22,600 in 88 and 84% yields, respectively. The linear relationship was observed between the fluorine contents and refractive indices of the obtained polyesters. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 213–222, 2003 相似文献
37.
Takao Yashiro Takashi Saithou Atsushi Kameyama Tadatomi Nishikubo 《Journal of polymer science. Part A, Polymer chemistry》2003,41(15):2304-2311
The polyaddition of 1,4‐bis[(3‐ethyl‐3‐oxetanyl)methoxymethyl]benzene with 2,2′‐bis[(4‐chloroformyl)oxyphenyl]propane was examined with quaternary onium salts as catalysts. When the polyaddition was carried out with tetrabutylphosphonium bromide in chlorobenzene at 120 °C for 24 h, the corresponding poly(alkyl aryl carbonate) with a high molecular weight (number‐average molecular weight = 16,700) was obtained in an almost quantitative yield. It was found from the 1H NMR and 13C NMR spectra of the obtained polymer that the addition reaction proceeded without any side reactions, providing the polycarbonate with pendant chloromethyl groups in the side chain. The polyaddition of bis{[3‐(3‐ethyloxetanyl)]methyl}terephthalate also proceeded smoothly and gave the corresponding polycarbonate with high molecular weight in a good yield. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 2304–2311, 2003 相似文献
38.
Two-magnon Raman scattering in the helical spin system at finite temperatures is studied by the two-time Green function method. The interaction between two magnons excited simultaneously by the incident light and the interaction between these magnons and other magnons excited thermally are included by use of a decoupling approximation similar to that of Callen. The temperature dependence of the line shape is calculated for the Γ+4 and Γ+5 modes in MnO2 and VF2. 相似文献
39.
Shouji Minegishi Tetsurou Otsuka Atsushi Kameyama Tadatomi Nishikubo 《Journal of polymer science. Part A, Polymer chemistry》2005,43(14):3105-3115
Phosphorus‐containing vinyl ether monomers and 1‐propenyl ether monomers were prepared by the regioselective addition reaction of glycidyl vinyl ether (GVE) or 1‐propenyl glycidyl ether with diaryl phosphonates with quaternary onium salts as catalysts. The reaction of GVE with bis(4‐chlorophenyl) phenylphosphonate gave bis[1‐(4‐chlorophenoxy methyl)‐2‐(vinyloxy)ethyl]phenylphosphonate in a 68% yield. The structures of the resulting phosphorus‐containing vinyl ether monomers and 1‐propenyl ether monomers were confirmed by IR and 1H NMR spectra and elemental analysis. Photoinitiated cationic polymerizations of the resulting phosphorus‐containing vinyl ether monomers and 1‐propenyl ether monomers were investigated with photoacid generators. The polymerization of vinyl ether groups and 1‐propenyl ether groups of the obtained monomers proceeded very smoothly with a sulfonium‐type cationic photoinitiator, bis[4‐(diphenylsulfonio)phenyl]sulfide‐bis(hexafluorophosphate), upon UV irradiation. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3105–3115, 2005 相似文献
40.
Tadatomi Nishikubo Takashi Iizawa Kazuo Kobayashi Makoto Okawara 《Tetrahedron letters》1981,22(39):3873-3874
Phase transfer catalyzed elimination reactions of -(2-bromoethyl)-benzylchloride with potassium hydroxide gave -chloromethylated styrene in high yield. 相似文献