Statistical analysis and simulation of pentad distributions of stereoblock polypropylenes

被引：47

作者：

Bruce, MD ^{[1
]}

Waymouth, RM ^{[1
]}

机构：

[1] Stanford Univ, Stanford, CA 94305 USA

来源：

MACROMOLECULES | 1998年 / 31卷 / 09期

关键词：

D O I：

10.1021/ma970942x

中图分类号：

O63 [高分子化学（高聚物）];

学科分类号：

070305 ; 080501 ; 081704 ;

摘要：

A method for simulating the microstructure of atactic-isotactic stereoblock polypropylene is presented. This method uses a computer program to generate stereosequences based on alternating blocks of isotactic and atactic stereosequences. Trends in observable stereochemical pentad distributions are examined, revealing that the pentad distributions become invariant above block lengths of 50 monomer units. These simulations reveal that two polymers with identical observable isotactic pentad distributions may have very different microstructures and thus different physical properties. The spectrum of an actual polymer is compared to the simulations, and it is revealed that many possible block lengths give reasonable fits but that similar values for weight fractions are obtained for each fit.

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页码：2707 / 2715

页数：9

相关论文

共 39 条

[1] MICROSTRUCTURE OF ELASTOMERIC POLYPROPYLENES OBTAINED WITH NONSYMMETRIC ANSA-TITANOCENE CATALYSTS [J].

BABU, GN ;

NEWMARK, RA ;

CHENG, HN ;

LLINAS, GH ;

CHIEN, JCW .

MACROMOLECULES, 1992, 25 (26) :7400-7402

[2]

BOVEY FA, 1972, HIGH RESOLUTION NMR

[3] Effect of metal on the stereospecificity of 2-arylindene catalysts for elastomeric polypropylene [J].

Bruce, MD ;

Coates, GW ;

Hauptman, E ;

Waymouth, RM ;

Ziller, JW .

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1997, 119 (46) :11174-11182

[4] Full assignment of the C-13 NMR spectra of regioregular polypropylenes: Methyl and methylene region [J].

Busico, V ;

Cipullo, R ;

Monaco, G ;

Vacatello, M ;

Segre, AL .

MACROMOLECULES, 1997, 30 (20) :6251-6263

[5] C-13 NMR EVIDENCE OF THE COPRESENCE OF M-RICH AND R-RICH SEQUENCES (STEREOBLOCKS) IN POLYPROPENE MOLECULES [J].

BUSICO, V ;

CORRADINI, P ;

DEBIASIO, R ;

LANDRIANI, L ;

SEGRE, AL .

MACROMOLECULES, 1994, 27 (16) :4521-4524

[6] New evidence on the nature of the active sites in heterogeneous Ziegler-Natta catalysts for propene polymerization [J].

Busico, V ;

Cipullo, R ;

Talarico, G ;

Segre, AL ;

Chadwick, JC .

MACROMOLECULES, 1997, 30 (16) :4786-4790

[7] ADVANCES IN THE C-13 NMR MICROSTRUCTURAL CHARACTERIZATION OF PROPENE POLYMERS [J].

BUSICO, V ;

CIPULLO, R ;

CORRADINI, P ;

LANDRIANI, L ;

VACATELLO, M ;

SEGRE, AL .

MACROMOLECULES, 1995, 28 (06) :1887-1892

[8] CONSECUTIVE 2-STATE STATISTICAL POLYMERIZATION MODELS [J].

CHENG, HN ;

BABU, GN ;

NEWMARK, RA ;

CHIEN, JCW .

MACROMOLECULES, 1992, 25 (25) :6980-6987

[9] 2-STATE PROPAGATION MECHANISM FOR PROPYLENE POLYMERIZATION CATALYZED BY RAC-[ANTI-ETHYLIDENE(1-ETA-5-TETRAMETHYLCYCLOPENTADIENYL)(1-ETA-5-INDENYL)]DIMETHYLTITANIUM [J].

CHIEN, JCW ;

LLINAS, GH ;

RAUSCH, MD ;

LIN, GY ;

WINTER, HH .

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1991, 113 (22) :8569-8570

[10] SERIES ON HOMOGENOUS ZIEGLER-NATTA CATALYSTS .11. KINETICS AND STEREOCHEMICAL CONTROL OF PROPYLENE POLYMERIZATION INITIATED BY ETHYLENE BIS(4,5,6,7-TETRAHYDRO-1-INDENYL) ZIRCONIUM DICHLORIDE METHYL ALUMINOXANE CATALYST [J].

CHIEN, JCW ;

SUGIMOTO, R .

JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY, 1991, 29 (04) :459-470

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