Protection and polymerization of functional monomers, 26. Synthesis of well-defined poly[4-(3′-butynyl)styrene] by means of anionic polymerization of 4-(4′-trimethylsilyl-3′-butynyl)styrene

✍ Scribed by Takashi Ishizone; Akira Hirao; Seiichi Nakahama; Katsuyuki Tsuda

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 599 KB
• Volume: 197
• Category: Article
• ISSN: 1022-1352
• DOI: 10.1002/macp.1996.021970517

✦ Synopsis

Abstract

Anionic polymerization of 4‐(4′‐trimethylsilyl‐3′‐butynyl)styrene (2) was carried out in THF at −78°C for 0.5 h with oligo(α‐methylstyryl)lithium, ‐dilithium, and ‐dipotassium. Poly(2)s possessing predicted molecular weights and narrow molecular weight distributions (M̄~w~/M̄~n~ < 1.11) were quantitatively obtained in all cases. By sequential anionic copolymerization of 2 and styrene, novel block copolymers, polystyrene‐block‐poly(2) starting either from living polystyrene or living poly(2), were synthesized. After completion of the polymerization, there occurred some gradual deactivation of the propagating carbanion of poly(2) at −78°C. This deactivation reaction could be almost completely suppressed at −95°C. The deprotection of poly(2) was performed by treating with Bu~4~NF in THF at 0°C for 1 h. The trimethylsilyl protecting group of poly(2) was completely removed to afford a poly[4‐(3′‐butynyl)styrene] of a controlled molecular structure.