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Ring‐Opening Metathesis Polymerization of endo‐ and exo‐Norbornene Lactones
Macromolecular Rapid Communications ( IF 4.2 ) Pub Date : 2020-08-18 , DOI: 10.1002/marc.202000326
Narumi Miyasako 1 , Shin-Ichi Matsuoka 1 , Masato Suzuki 1
Affiliation  

New ester‐functionalized bicyclic aliphatic polymers are synthesized through the ring‐opening metathesis polymerization (ROMP) of endo‐ and exo‐norbornene lactones (endo‐NBL and exo‐NBL) and their oxa‐norbornene analogue (exo‐oxa‐NBL) followed by hydrogenation. The polymerizability between endo‐ and exo‐NBLs, and the thermal properties between the six types of polymers before and after hydrogenation are compared and discussed. The ROMP of all three monomers proceeded in a living fashion under optimized conditions, which is confirmed by chain extension experiments. Endo‐NBL shows a much lower homo‐ and copolymerizability than exo‐NBL probably owing to six‐membered chelation to the Ru center and steric hindrance in the ruthenacyclobutane intermediate. Stereo‐block and stereo‐gradient copolymers of poly(endo‐NBL) and poly(exo‐NBL) are also synthesized. The hydrogenation catalyzed by RuHCl(CO)(PPh3)3 in the mixed solvents of o‐xylene and N,N‐dimethyl acetamide (DMAc) results in more than 95% conversion. The obtained hydrogenated polymers, H‐poly(endo‐NBL) and H‐poly(exo‐NBL), are amorphous, soluble in chlorinated aliphatic solvents, and thermally stable until 400 °C without a weight loss. Their glass transition temperatures are 163 and 131 °C, respectively; the values are appropriate in terms of both thermal stability and processing deformation for the application of transparent resin materials.

中文翻译:

内-和外-降冰片烯内酯的开环易位聚合

新酯官能化的脂族双环聚合物通过开环易位聚合的(ROMP)中合成内切和-外型降冰片烯内酯(内切-NBL和-NBL)和它们的氧杂-降冰片烯类似物(接着氧杂NBL)通过氢化。之间的聚合性内切-和外切-NBLs和六种类型的氢化前后聚合物的之间的热性能进行了比较和讨论。在优化的条件下,所有三种单体的ROMP均以活泼的方式进行,这已通过扩链实验得到证实。Endo‐ NBL的均聚物和共聚性比exo- NBL可能是由于六元碳原子与Ru中心的螯合以及钌烷基环丁烷中间体的空间位阻所致。还合成了poly(endo- NBL)和poly(exo- NBL)的立体嵌段共聚物和立体梯度共聚物。Ru-HCl(CO)(PPh 33二甲苯和NN-二甲基乙酰胺(DMAc)的混合溶剂中催化的氢化反应可实现95%以上的转化率。获得的氢化聚合物H-poly(endo - NBL)和H-poly(exo‐NBL)是无定形的,溶于氯化脂族溶剂中,在不降低重量的情况下直至400°C都具有热稳定性。它们的玻璃化转变温度分别为163和131°C。对于透明树脂材料的应用,该值在热稳定性和加工变形方面都合适。
更新日期:2020-08-18
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