ISOSPECIFIC POLYMERIZATION OF METHYL-METHACRYLATE INITIATED BY CHIRAL ZIRCONOCENEDIMETHYL/PH(3)CB(C6F5)(4) IN THE PRESENCE OF LEWIS-ACID

被引：121

作者：

DENG, H ^{[1
]}

SHIONO, T ^{[1
]}

SOGA, K ^{[1
]}

机构：

[1] TOKYO INST TECHNOL,RESOURCES UTILIZAT RES LAB,MIDORI KU,YOKOHAMA,KANAGAWA 227,JAPAN

来源：

MACROMOLECULES | 1995年 / 28卷 / 09期

关键词：

D O I：

10.1021/ma00113a008

中图分类号：

O63 [高分子化学（高聚物）];

学科分类号：

070305 ; 080501 ; 081704 ;

摘要：

Polymerization of methyl methacrylate (MMA) was conducted with the catalyst systems of rac-Et(Ind)(2)Zr(CH3)(2)/Ph(3)CB(C6F5)(4), rac-Et(IndH(4))(2)Zr(CH3)(2)/Ph(3)CB(C6F5)(4), and rac-Me(2)Si(Ind)(2)Zr(CH3)(2)/Ph(3)CB(C6F5)(4). These catalysts only were found to be inactive. However, the addition of suitable Lewis acids like alkylzinc and alkylaluminum compounds gave highly isotactic PMMA. The isotactic pentad [mmmm] in PMMA as well as the propagation rate constant (k(p)) depended significantly upon the zirconocene compounds. Both the microstructure ([mmmm]) and propagation rate constant (k(p)) increased in the following order: Me(2)Si(Ind)(2) < Et(IndH(4))(2) < Et(Ind)(2). The microstructure of PMMA was also affected slightly by alkylzinc compounds: (CH2)(2)CH=CH2 < CH2CH3 > (CH2)(3)CH3. When the polymerization was initiated by the rac-Et(Ind)(2)Zr(CH3)(2)/Ph(3)CB(C6F5)(4)/Zn(C2H4CH=CH2)(2) catalyst system at 0 degrees C in toluene, the molecular weight of PMMA increased in proportion to the conversion of MMA. The increase of temperature from 0 to 80 degrees C caused a decrease in isotactic pentad content by approximately 10%. The isotactic polymerization of MMA was revealed to proceed by an enantiomorphic site-controlled mechanism.

引用

页码：3067 / 3073

页数：7

共 14 条

[1] Yasuda H., Yamamoto H., Yokota K., Miyake S., Nakamura A., J. Am. Chem. Soc., 114, (1992)
[2] Yasuda H., Yamamoto H., Yamashita M., Macromolecules, 26, (1993)
[3] Bovey F.A., Tiers G.V.D., J. Polym. Sci., 44, (1960)
[4] Hatada K., Kitayama T., Ute K., Prog. Polym. Sci., 13, (1988)
[5] Chien J.C.W., Tsai W.M., Rausch M.D., J. Am. Chem. Soc., 113, (1991)
[6] Shelden R.A., Fueno T., Tsunetsugu T., frukawa J., J. Polym. Sci., Polym. Lett., 3, (1962)
[7] Soga K., Deng H., Yano T., Shiono T., Macromolecules, 27, (1994)
[8] Deng H., Shiono T., Soga K., Macromol. Chem. Phys.
[9] Kaminsky W., Kulper K., Brintzinger H.H., Wild F.R.W.P., Angew. Chem., 97, (1985)
[10] Herrmann W.A., Rohrmann J., Herdtweck E., Spaleck W., Winter A., Angew. Chem., 101, (1989)

← 1 2 →