In:
Polymer International, Wiley, Vol. 54, No. 2 ( 2005-02), p. 374-380
Abstract:
Polydimethylsiloxane‐ block ‐polystyrene‐ block ‐polydimethylsiloxane (PDMS‐ b ‐PS‐ b ‐PDMS) was synthesized by the radical polymerization of styrene using a polydimethylsiloxane‐based macroazoinitiator (PDMS MAI) in supercritical CO 2 . PDMS MAI was synthesized by reacting hydroxy‐terminated PDMS and 4,4′‐azobis(4‐cyanopentanoyl chloride) (ACPC) having a thermodegradable azo‐linkage at room temperature. The polymerization of styrene initiated by PDMS MAI was investigated in a batch system using supercritical CO 2 as the reaction medium. PDMS MAI was found to behave as a polyazoinitiator for radical block copolymerization of styrene, but not as a surfactant. The response surface methodology was used to design the experiments. The parameters used were pressure, temperature, PDMS MAI concentration and reaction time. These parameters were investigated at three levels (−1, 0 and 1). The dependent variable was taken as the polymerization yield of styrene. PDMS MAI and PDMS‐ b ‐PS‐ b ‐PDMS copolymers obtained were characterized by proton nuclear magnetic resonance and infrared spectroscopy. The number‐ and weight‐average molecular weights of block copolymers were determined by gel permeation chromatography. Copyright © 2004 Society of Chemical Industry
Type of Medium:
Online Resource
ISSN:
0959-8103
,
1097-0126
Language:
English
Publisher:
Wiley
Publication Date:
2005
detail.hit.zdb_id:
2004753-8
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