Polystyrene-b-polydimethyl siloxane (PDMS) multicomponent polymer networks: Styrene polymerization with macromonomeric initiators (macroinimers) having PDMS units

• Published in: Polymer (Guilford) 1997-06, Vol.38 (12), p.2981-2987
• Main Authors: Elif Hamurcu, E., Hazer, Baki, Baysal, B.M.
• Format: Article
• Language: English
• Subjects: Applied sciences; Chemical modifications; Exact sciences and technology; Inorganic and organomineral polymers; macroinimer; Physicochemistry of polymers; poly(dimethylsiloxane); poly(S-b-PDMS) polymer network
• ISSN: 0032-3861; 1873-2291
• DOI: 10.1016/S0032-3861(96)00864-6

A new macromonomeric initiator (macroinimer) was synthesized and evaluated for the bulk polymerization of styrene at 60 and 80°C. The macroinimer containing poly(dimethylsiloxane), PDMS, was synthesized via condensation reactions between 4,-4′-azobis-4-cyanopentanoyl chloride (ACPC), PDMS and methacryloyl chloride. The product (MIM I) was thermally homopolymerized and copolymerized with styrene in bulk. Kinetics of radical polymerization of styrene with MIM I at 60°C and at low conversion was studied. Rate constant K, k p( fk d/ k t) 1/2, was estimated from kinetic data as 1.15 × 10 −4 1 1/2 mol −1/2 s. Bulk polymerization of styrene with macroinimers at 80°C gave crosslinked block copolymers. D.s.c. measurements showed that crosslinked block copolymers had a glass transition temperature around 45°C. This is evidence of a plasticizing effect of flexible polysiloxane segments in copolymers. Crosslinked PDMS-b-PS block copolymers obtained using macroinimers may be an interesting group of thermoplastic elastomers.