Longfei Li,Hong Zhai,Tao Wang,Xibo Qiu,Na Qiang,Peng Dong,Ying Bai,Ai-Yun Peng,Daping Quan
The ring-opening copolymerization of lactide with carbonate is an available strategy to incorporate reactive groups to the pendent sites of copolymer for further functional modification. A series of random and block copolymers were synthesized from l -lactide ( L -LA) and 2-bromomethyl-2-methyltrimethylene carbonate (BMTC) using dodecanol as initiator and stannous octoate as catalyst. The structures of the copolymers were characterized by nuclear magnetic resonance ( 1 H NMR, 13 C NMR), gel permeation chromatography (GPC) and differential scanning calorimetry (DSC). The composition of the copolymers can be controlled through changing the feed ratios of n BMTC / n L -LA . It was found the random P(BMTC- co - L LA) copolymers had the semicrystalline characteristic due to the relative long block-like segments of P L LA ( L L , P L LA = 5.3–7.3) and the polar interactions from bromo groups , but their crystallinity ( X c, P L LA ) and melting temperature ( T m, P L LA ) decreased when the BMTC content increased. The X c, P L LA and T m, P L LA of P(BMTC- b -P L LA) block copolymers were relatively higher than the corresponding random copolymers, and approached gradually to the pure P L LA with the increase of the molecular weight of P L LA block. Finally, the pendent bromo groups of P(BMTC- co - L LA) were easily transformed into azides , which could proceed the azide-alkyne click reaction smoothly and quantitatively at room temperature .
危险品化学品经营许可证（带存储）