Synthesis of poly(L‐lactide)‐block‐polyisobutylene‐block‐poly(L‐lactide), a new biodegradable thermoplastic elastomer

Abstract

The anionic ring-opening polymerization of L-lactide was initiated by dipotassium-polyisobutylene-alcoholate telechelic polymer to yield poly(L-lactide)-block-polyisobutylene-block-poly(L-lactide) triblock copolymer, a partially biodegradable thermoplastic elastomer. The pure triblock copolymer was obtained by gradient column chromatography on silica gel. The molar mass and molar mass distribution of the block copolymer was ascertained by SEC and quantitative ' H NMR spectroscopy. It showed two glass transitions and microphase separation.

Synthesis of Polyisobutylene-Based Block Copolymers with Precisely Controlled Architecture by Living Cationic Polymerization

“…Although site-transformation has been utilized extensively for the synthesis of block copolymers, only a few PIB/crystalline block copolymers such as poly(L-lactide-b-IB-b-L-lactide) [92], poly(IB-b-e-caprolactone(e-CL)) [93] diblock and poly(e-CL-b-IB-b-e-CL) [94] triblock copolymers with relatively short PIB block segment (M n 10,000 g/mol) were reported. This is most likely due to difficulties in quantitative end-functionalization of high molecular weight PIB.…”

Living cationic sequential block copolymerization: synthesis and characterization of poly(4-(2-hydroxyethyl)styrene-b-isobutylene-b-4-(2-hydroxyethyl)styrene) triblock copolymers

“…However, many polar monomers do not undergo cationic polymerization. Although the combination of cationic polymerization with other living polymerization techniques has been successful for the synthesis of PIB block copolymers with, for example, poly(L-lactide) 18 and poly(e-caprolactone) 19 end segments, mechanistic transformation reactions are rather complicated. It is more useful to introduce (protected) polar functional groups to monomers that undergo cationic polymerization, as block copolymer synthesis may be accomplished in a relatively simple one-pot procedure using these monomers.…”

Quantitative syntheses of novel polyisobutylenes fitted with terminal primary Br, OH, NH2, and methacrylate termini

“…[1][2][3][4][5][6][7][8] The synthesis of these materials was summarized and reviewed in a 1991 book, 1 and since that time the field has steadily grown. [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] Regretfully, however, all the published procedures involve relatively expensive transformations and/or afford incomplete end-functionalization.…”