Effect of Disyndiotacticity on the Glass Transition Temperature of Poly(ethyl crotonate)s Synthesized by Group-Transfer Polymerization Catalyzed by Organic Acids
Effect of Disyndiotacticity on the Glass Transition Temperature of Poly(ethyl crotonate)s Synthesized by Group-Transfer Polymerization Catalyzed by Organic Acids
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二间同立构规整度对有机酸基团转移聚合聚巴豆酸乙酯玻璃化转变温度的影响
DOI：
10.1021/acs.macromol.0c01122
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发表时间：
2020
期刊：
影响因子：
5.5
通讯作者：
Abe Hideki
中科院分区：
文献类型：
--
作者：
Imada Motosuke;Takenaka Yasumasa;Tsuge Takeharu;Abe Hideki
摘要以三烷基硅基、三乙基硅基、叔丁基二甲基硅基和三异丙基硅基为引发剂，采用基团转移聚合的方法合成了具有多种双双活性的聚巴东酸乙酯（PECs）。催化剂和引发剂的硅基部分的空间位阻以及较低的聚合温度大大增强了聚羧酸乙酯的双聚性。动态力学分析表明，高的非溶性提高了PECs的耐热性。DMA测定的玻璃化转变温度（Tg）分别为201℃和82℃，分别为92%和53%。与双规聚甲基丙烯酸甲酯相比，高战术强度下的增强足够大。这是由于聚合物链的规则排列源于高度控制的二偶性，正如偏光显微照片和x射线衍射图分析所支持的那样。
Poly(ethyl crotonate)s (PECs), possessing various disyndiotacticities, were synthesized by group-transfer polymerization using several silicon Lewis acid catalysts likeN-(trialkylsilyl)bis(trifluoromethanesulfonyl)imides (trialkylsilyl = trimethylsilyl, triethylsilyl,tert-butyldimethylsilyl, and triisopropylsilyl) and silyl ketene acetals with a corresponding trialkylsilyl moiety as an initiator. Disyndiotacticity of PECs was greatly enhanced by steric hindrance from the silyl moiety of the catalyst and initiator and also by low polymerization temperature. Dynamic mechanical analysis of the obtained PECs revealed that high disyndiotacticity improves heat resistance. The glass transition temperature (Tg) measured by DMA was 201 °C at 92% disyndiotacticity and 82 °C at 53% disyndiotacticity. TheTgenhancement at high tacticity was sufficiently large when compared to syndiotactic poly(methyl methacrylate). This is attributed to the regular arrangement of polymer chains derived from highly controlled ditacticity, as supported by analysis of polarizing optical micrographs and X-ray diffraction patterns.
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影响因子：
2.8
作者：
K. Ute;Toshiyuki Tarao;T. Kitayama
通讯作者：
K. Ute;Toshiyuki Tarao;T. Kitayama
DOI：
10.1080/00222348608248039
发表时间：
1986-01-01
期刊：
JOURNAL OF MACROMOLECULAR SCIENCE-PHYSICS
影响因子：
--
作者：
DENNY, LR;BOYER, RF;ELIAS, HG
通讯作者：
ELIAS, HG
影响因子：
5.5
作者：
R. Kakuchi;K. Chiba;Keita Fuchise;R. Sakai;T. Satoh;T. Kakuchi
通讯作者：
R. Kakuchi;K. Chiba;Keita Fuchise;R. Sakai;T. Satoh;T. Kakuchi
影响因子：
5.9
作者：
Imada, Motosuke;Takenaka, Yasumasa;Abe, Hideki
通讯作者：
Abe, Hideki
聚甲基丙烯醚的双全同立构规整度和阳离子聚合中甲基丙烯醚的双键开环
DOI：
10.1002/pol.1967.150051204
发表时间：
1967
期刊：
Journal of Polymer Science Part A
影响因子：
--
作者：
Y. Ohsumi;T. Higashimura;S. Okamura;R. Chǔjǒ;T. Kuroda
通讯作者：
T. Kuroda