Synthesis and physical properties of poly(l‐lactic acid)‐poly(dimethyl siloxane) multiblock copolymers prepared by direct polycondensation. Issue 9 (30th November 2013)

• Record Type: Journal Article
• Authors: Fukae, Ryohei; Okada, Yoshiro; Kawatsuki, Nobuhiro
• Is Part Of: Journal of applied polymer science. Volume 131:Issue 9(2014:May 05)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2013-11-30
• Subjects: Polymers -- Periodicals; Polymerization -- Periodicals; 668.9
• DOI: 10.1002/app.40211
• Languages: English
• ISSNs: 0021-8995

Abstract

<abstract abstract-type="main"> <title>ABSTRACT</title> <p>Multiblock copolymers consisting of poly(<sc>l</sc>‐lactic acid) and poly(dimethyl siloxane) were prepared by the polycondensation of oligo(<sc>l</sc>‐lactic acid) (OLLA) with dihydroxyl‐terminated oligo(dimethyl siloxane) and dicarboxyl‐terminated oligo(dimethyl siloxane). Copolymers with number‐average molecular weights of 18, 000−33, 000 Da and various content ratios of oligo(dimethyl siloxane) (ODMS) unit were obtained by changing the feed ratio of these oligomers. A film prepared from the copolymer with an ODMS content ratio of 0.37 exhibited two independent peaks at −107°C and 37°C in the mechanical loss tangent for temperature dependence, suggesting the formation of microphase separation between the OLLA and ODMS segments. The film had a tensile strength of 3.2 MPa and a high elongation of 132%. The film also exhibited a high strain recovery even after repeated straining. The incorporation of dimethyl siloxane units as multiblock segments was confirmed to improve the flexibility of poly(<sc>l</sc>‐lactic acid). © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. <bold>2014</bold>, <italic>131</italic>, 40211.</p> </abstract>