Synthesis and characterization of cis-polybutadiene-block-syn-polystyrene copolymers with a cyclopentadienyl titanium trichloride/modified methylaluminoxane catalyst

被引:25
作者
Ban, HT
Tsunogae, Y
Shiono, T
机构
[1] Japan Chem Innovat Inst, Tsukuba, Ibaraki 3058565, Japan
[2] Zeon Corp, R&D Ctr, Kawasaki Ku, Kawasaki, Kanagawa 2109507, Japan
[3] Tokyo Inst Technol, Chem Resources Lab, Midori Ku, Yokohama, Kanagawa 2268503, Japan
关键词
butadiene-styrene; block copolymers; half-metallocene; aluminoxane; stereospecific living polymerization; catalysts; crystallization;
D O I
10.1002/pola.20144
中图分类号
O63 [高分子化学(高聚物)];
学科分类号
070305 ; 080501 ; 081704 ;
摘要
This article reports a practical method for preparing cis-polybutadiene-block-syn-polystyrene (cis-PB-b-syn-PS) copolymers with long crystallizable syndiotactic polystyrene (syn-PS) segments chemically bonded with high cis-1,4-polybutadiene segments through the addition of styrene (ST) to a cis-specific 1,1,3-butadiene (BD) living catalyst composed of cyclopentadienyl titanium trichloride (CpTiCl3) and modified methylaluminoxane (MMAO). The incorporation of ST into the living polybutadiene (PB) precursor remarkably depended on the polymerization temperature. A low temperature (-20 degreesC) suppressed the rate of ST incorporation, but a high temperature (50 degreesC) tended to decompose the livingness of the active species and enhance the rate of the aspecific ST polymerization initiated by MMAO. Consequently, temperatures of 0-25 degreesC seemed to be best for this copolymerization system. Because of the absence of ST livingness, the final products contained not only the block copolymer but also the homopolyrners. Attempts to isolate the block copolymer were carried out with common solvent fractionation techniques, but the results were not sufficient. Cross-fractionation chromatography was, therefore, used for the isolation of the cis-PB-b-syn-PS copolymer. The presence of long Syn-PS segments was confirmed by the observation of a strong endothermic peak at 260 degreesC in the differential scanning calorimetry curve. (C) 2004 Wiley Periodicals, Inc.
引用
收藏
页码:2698 / 2704
页数:7
相关论文
共 53 条
[1]  
BAN HT, 2002, POLYM PREPR JPN, V51, P1639
[2]   MICROSTRUCTURES OF POLYBUTADIENES PREPARED BY ANIONIC-POLYMERIZATION IN POLAR-SOLVENTS - ION-PAIR AND SOLVENT EFFECTS [J].
BYWATER, S ;
FIRAT, Y ;
BLACK, PE .
JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY, 1984, 22 (03) :669-672
[3]   Structural characterization of novel styrene-butadiene block copolymers containing syndiotactic styrene homosequences [J].
Caprio, M ;
Serra, MC ;
Bowen, DE ;
Grassi, A .
MACROMOLECULES, 2002, 35 (25) :9315-9322
[4]  
Coates GW, 2002, ANGEW CHEM INT EDIT, V41, P2236, DOI 10.1002/1521-3773(20020703)41:13<2236::AID-ANIE2236>3.0.CO
[5]  
2-3
[6]   Living polymerizations of propylene and syntheses of atactic polypropylene-block-poly(ethylene-co-propylene) using metallocene catalyst systems [J].
Fukui, Y ;
Murata, M .
APPLIED CATALYSIS A-GENERAL, 2002, 237 (1-2) :1-10
[7]  
Fukui Y, 2001, MACROMOL CHEM PHYS, V202, P1430, DOI 10.1002/1521-3935(20010501)202:8<1430::AID-MACP1430>3.0.CO
[8]  
2-T
[9]  
Fukui Y, 2001, MACROMOL CHEM PHYS, V202, P1473, DOI 10.1002/1521-3935(20010601)202:9<1473::AID-MACP1473>3.0.CO
[10]  
2-1