Premium
Synthesis of ultra‐high molecular weight polystyrene with rare earth–magnesium alkyl catalyst system: general features of bulk polymerization
Author(s) -
Jiang Liming,
Shen Zhiquan,
Yang Yuhui,
Zhang Yifeng
Publication year - 2001
Publication title -
polymer international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.592
H-Index - 105
eISSN - 1097-0126
pISSN - 0959-8103
DOI - 10.1002/1097-0126(200101)50:1<63::aid-pi561>3.0.co;2-l
Subject(s) - polystyrene , styrene , polymerization , catalysis , molar mass distribution , alkyl , polymer chemistry , materials science , magnesium , nuclear chemistry , chemistry , polymer , copolymer , organic chemistry , metallurgy
Bulk polymerization of styrene (St) with an in‐situ‐activated Ziegler‐catalyst containing neodymium 2‐ethylhexyl phosphonate [Nd(P 204 ) 3 ], magnesium–aluminum alkyls $(\hbox{MgBu}_{2}^{n}\hbox to 6pt{\hrulefill} \hbox{AlEt}_{3})$ and hexamethyl phosphoramide (HMPA) was studied. The new rare‐earth catalyst exhibited high activity for polymerization of styrene, and its catalytic efficiency reached 14 730 g PSt/g Nd. The influence of reaction parameters, such as Mg/Nd, Mg/Al, St/Nd molar ratios, temperature, etc, on the catalyst performance was examined in detail. The molecular weight of the resulting polystyrene is ultra‐high ( M W = 40 × 10 4 ∼ 120 × 10 4 g mol −1 ) and the distribution of molecular weight is broad ( M W / M n = 2.1 ∼ 2.8). The microstructure of the polystyrene was characterized by IR and 13 C NMR spectroscopies and found to be atactic. © 2001 Society of Chemical Industry