Synthesis and thermal properties of poly(2,2-dimethyltrimethylene carbonate)-block-poly(tetrahydrofuran)-block-poly(2,2-dimethyltrimethylene carbonate)

✍ Scribed by Achim Josef Müller; Helmut Keul; Hartwig Höcker

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 509 KB
• Volume: 29
• Category: Article
• ISSN: 0014-3057
• DOI: 10.1016/0014-3057(93)90145-6

✦ Synopsis

Almtract--Alkalimetal salts (Li +, K +) and metal-free salts ([(CH3)2N]3S +, Bu4N + ) of hydroxytelechelic poly(THF) were used as initiators for the anionic ring-opening polymerization of 2,2-dimethyltrimethylene carbonate (DTC). With both systems triblock copolymers were obtained with a monomodal distribution of molecular weights, with one exception. Copolymers with equal length of the poly(DTC) block and increasing molecular weight of the initiating block show the following features: (i) no influence at low molecular weights of the initiator (Jr/,--650); (ii) plasticizing effect in the range 1000 < M, < 2600; (iii) two phase systems at K/, > 2600. The triblock structure of the copolymers was established by degradation of the POly(THF) middle block under acidic conditions with subsequent IH-NMR and GPC analysis.