MOLECULAR-ORIENTATION IN DEFORMED BIMODAL NETWORKS .1. THEORY

被引:15
作者
BAHAR, I
ERMAN, B
BOKOBZA, L
MONNERIE, L
机构
[1] BOGAZICI UNIV,SCH ENGN,BEBEK 80815,TURKEY
[2] ECOLE SUPER PHYS & CHIM IND VILLE PARIS,PHYSICOCHIM STRUCT & MACROMOLEC LAB,F-75231 PARIS 05,FRANCE
[3] TUBITAK,ADV POLYMER MAT RES CTR,BEBEK 80815,TURKEY
关键词
D O I
10.1021/ma00105a029
中图分类号
O63 [高分子化学(高聚物)];
学科分类号
070305 ; 080501 ; 081704 ;
摘要
Expressions for the molecular orientation of long and short chains in bimodal networks, SL and Ss, are derived based on the theory developed by Kloczkowski et al. (Macromolecules 1991, 24, 3266) for regular bimodal phantom networks and compared with those (S-L degrees and S-S degrees) occurring in,corresponding unimodal networks. The changes in segmental orientation of the respective chains in bimodal networks relative to their unimodal counterparts, expressed as the ratio S-L/S-L degrees or S-S/S-S degrees, are shown to be independent of macroscopic strain and intrinsic chain configurational characteristics but depend essentially on network topology and composition. The latter are accounted for by two variables: the ratio xi of the molecular weights of short chains to that of long chains, and the number phi(S) and phi(L) of short and long chains at each junction. Results of the formulation show that the long (short) chains in the bimodal network orient more (less) than those in the corresponding unimodal network. These differences in the orientation behavior of the two chains arise from differences in fluctuations of chain dimensions that, in turn, affect the microscopic strain of each component. Predictions of the theory are compared in the following paper with results of Fourier transform infrared measurements on well-defined poly(dimethylsiloxane) networks.
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页码:225 / 230
页数:6
相关论文
共 14 条
[1]   MOLECULAR-ORIENTATION IN DEFORMED BIMODAL NETWORKS .2. FOURIER-TRANSFORM INFRARED MEASUREMENTS ON POLY(DIMETHYLSILOXANE) NETWORKS AND COMPARISON WITH THEORY [J].
BESBES, S ;
BOKOBZA, L ;
MONNERIE, L ;
BAHAR, I ;
ERMAN, B .
MACROMOLECULES, 1995, 28 (01) :231-235
[2]  
CHAPELLIER B, 1993, J PHYS II, V3, P1619, DOI 10.1051/jp2:1993222
[3]   EFFECTS OF CHAIN STRUCTURE AND NETWORK CONSTITUTION ON SEGMENTAL ORIENTATION IN DEFORMED AMORPHOUS NETWORKS [J].
ERMAN, B ;
BAHAR, I .
MACROMOLECULES, 1988, 21 (02) :452-457
[4]   THEORY OF STRAIN BIREFRINGENCE OF AMORPHOUS POLYMER NETWORKS [J].
ERMAN, B ;
FLORY, PJ .
MACROMOLECULES, 1983, 16 (10) :1601-1606
[5]   EXPERIMENTAL RESULTS RELATING STRESS AND BIREFRINGENCE TO STRAIN IN POLY(DIMETHYLSILOXANE) NETWORKS - COMPARISONS WITH THEORY [J].
ERMAN, B ;
FLORY, PJ .
MACROMOLECULES, 1983, 16 (10) :1607-1613
[6]   THEORY OF SEGMENTAL ORIENTATION IN AMORPHOUS POLYMER NETWORKS [J].
ERMAN, B ;
MONNERIE, L .
MACROMOLECULES, 1985, 18 (10) :1985-1991
[7]  
ERMAN B, 1991, MACROMOLECULES, V24, P901, DOI 10.1021/ma00004a015
[8]   STATISTICAL THERMODYNAMICS OF RANDOM NETWORKS [J].
FLORY, PJ .
PROCEEDINGS OF THE ROYAL SOCIETY OF LONDON SERIES A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES, 1976, 351 (1666) :351-380
[9]   SEGMENTAL ORIENTATION AND INFRARED DICHROISM OF MODEL BIMODAL ELASTOMERIC NETWORKS [J].
HANYU, A ;
STEIN, RS .
MAKROMOLEKULARE CHEMIE-MACROMOLECULAR SYMPOSIA, 1991, 45 :189-203
[10]   POLYDISPERSE POLYMER NETWORKS - ELASTICITY, ORIENTATIONAL PROPERTIES, AND SMALL-ANGLE NEUTRON-SCATTERING [J].
HIGGS, PG ;
BALL, RC .
JOURNAL DE PHYSIQUE, 1988, 49 (10) :1785-1811