Indexed by:期刊论文

Date of Publication:2014-04-15

Journal:JOURNAL OF APPLIED POLYMER SCIENCE

Included Journals:SCIE、EI、Scopus

Volume:131

Issue:8

ISSN No.:0021-8995

Key Words:catalysts; rubber; addition polymerization

Abstract:The polymerization of isoprene was examined by using a novel binary catalyst system composed of neodymium chloride tributylphosphate (NdCl3 center dot 3TBP) and methylaluminoxane (MAO). The NdCl3 center dot 3TBP/MAO catalyst worked effectively in a low MAO level ([Al]/[Nd]=50) to afford polymers with high molecular weight (M-n approximate to 10(5)), narrow molecular weight distribution (M-w/M-n=1.4-1.6), and high cis-1,4 stereoregularity (> 96%). The catalytic activity increased with an increasing [Al]/[Nd] ratio from 30 to 100 and polymerization temperature from 0 to 50 degrees C, while the M-n of polymer decreased. The presence of free TBP resulted in low polymer yield. Polymerization solvent remarkably affected the polymerization behaviors; the polymerizations in aliphatic solvents (cyclohexane and hexane) gave polymer in higher yield than that in toluene. The M-w/M-n ratio of the producing polymer remained around 1.5 and the gel permeation chromatographic curve was always unimodal, indicating the presence of a single active site in the polymerization system. (c) 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40153.