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Syndiospecific styrene polymerization with CpTiCl 3 /MAO: Effects of the order of reactant addition on polymerization and polymer properties
Author(s) -
Huang Bill,
Cao Kun,
Li BoGeng,
Zhu Shiping
Publication year - 2004
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.21050
Subject(s) - polymerization , methylaluminoxane , polymer chemistry , polystyrene , styrene , tacticity , materials science , differential scanning calorimetry , monomer , polymer , molar mass distribution , copolymer , catalysis , bulk polymerization , radical polymerization , chemistry , metallocene , organic chemistry , composite material , thermodynamics , physics
Abstract Syndiospecific styrene (St) polymerization, catalyzed by the CpTiCl 3 /methylaluminoxane (MAO) system, was investigated using two different activation procedures. The polymerization parameters included polymerization time, temperature (∼25–100°C), ratio of [Al]/[Ti] (∼100–1000), and catalyst precursor concentration (∼0.5–10.0 × 10 −4 mol Ti/L). It was found that adding reactants in the order of (CpTiCl 3 + MAO) + St (Injection of Styrene mode) gave much higher monomer conversion rates, higher weight‐average molecular weights, and narrower molecular weight distributions than for the (St + MAO) + CpTiCl 3 (Injection of Catalyst mode). The former also yielded significantly higher syndiotacticity fractions. Differential scanning calorimetry measurements showed multiple peaks exhibiting polymorphism in crystalline syndiotactic polystyrene samples. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1449–1455, 2004