二醇
高分子化学
氢氧化物
化学
聚碳酸酯
摩尔质量
氧阴离子
开环聚合
分散性
共聚物
聚合
亲核细胞
亚甲基
铬
二胺
二聚体
氧化环己烯
药物化学
聚合物
有机化学
催化作用
作者
Kaijie Ni,Louise N. Dawe,Amy A. Sarjeant,Christopher M. Kozak
出处
期刊:Dalton Transactions
[The Royal Society of Chemistry]
日期:2023-01-01
卷期号:52 (46): 17249-17257
摘要
A diamine-bis(phenolate) chromium(III) complex, CrOH[L] ([L] = dimethylaminoethylamino-N,N-bis(2-methylene-4,6-tert-butylphenolate)), 2, in the presence of tetrabutylammonium hydroxide effectively copolymerizes CO2 and cyclohexene oxide (CHO) into a polycarbonate diol. The resultant low molar mass (6.3 kg mol-1) diol is used to initiate ring-opening polymerization of rac-lactide with 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) giving ABA-type block copolymers with good molar mass control through varying rac-LA-to-diol loadings and with narrow dispersities. As the degree of rac-LA incorporation increases, the glass transition temperatures (Tg) are found to decrease, whereas decomposition temperatures (Td) increase. (Diphenylphosphonimido)triphenylphosphorane (Ph2P(O)NPPh3) was used as a neutral nucleophilic cocatalyst with 2, giving phosphorus-containing polycarbonates with an Mn value of 28.5 kg mol-1, a dispersity of 1.13, a Tg value of 110 °C and a Td value of over 300 °C. A related Cr(III) complex (4) having a methoxyethyl pendent group rather than a dimethylaminoethyl group was structurally characterized as a hydroxide-bridged dimer.
科研通智能强力驱动
Strongly Powered by AbleSci AI