Stereoblock-like Brush Copolymers Consisting of Poly(L-lactide) and Poly(D-lactide) Side Chains along Poly(norbornene) Backbone: Synthesis, Stereocomplex Formation, and Structure-Property Relationship

作者：Isono Takuya; Kondo Yohei; Ozawa Shun; Chen Yougen; Sakai Ryosuke; Sato Shin ichiro; Tajima Kenji; Kakuchi Toyoji; Satoh Toshifumi^*

来源：Macromolecules, 2014, 47(20): 7118-7128.

DOI：10.1021/ma501647m

Random and block copolymerizations of poly(l-lactide) (PLLA) and poly(d-lactide) (PDLA) macromonomers having an exo-norbornene group at the alpha- or pi-chain end (D/L ratio = 1/1, M-n = ca. 5000 g mol(-1)) were performed via ring-opening metathesis polymerization to produce the brush random and block copolymers consisting of parallel or antiparallel aligned PLLA and PDLA side chains on a poly(norbornene) backbone. The molecular weight and polydispersity index of the brush copolymers were in the range of 40 300-458 000 g mol(-1) and 1.031.14, respectively. Despite such high molecular weights, these brush copolymers formed a stereocomplex without homochiral crystallization. The melting temperature (T-m) and crystallinity (X) of the resulting stereocomplex varied depending on the backbone length, relative chain direction, and distribution of the PLLA/PDLA side chains. The parallel brush copolymers showed significantly higher T-m and X values than the antiparallel ones.

• 出版日期2014-10-28