Mixtures of an acid-functionalized mesogen with poly(4-vinylpyridine)

被引:60
作者
Brandys, FA
Bazuin, CG
机构
[1] Ctr. Rech. Sci. Ingenierie M., Département de Chimie, Université Laval, Qué.
关键词
D O I
10.1021/cm950240r
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
A thermotropic dialkoxy biphenyl liquid crystal, functionalized by a carboxylic acid group at one extremity, is mixed to varying proportions with poly(4-vinylpyridine) (P4VP). The liquid crystal, LC-4,6A, is characterized by a monotropic smectic A phase and a highly ordered or crystalline lamellar phase formed primarily of acid dimers. In the mixtures with P4VP (studied up to acid/pyridine molar ratios of 1.0), the fluid mesophase is suppressed. A solid-isotropic phase transition is present above a molar ratio of about 0.2, whereas for lower LC-4,6A contents the mixtures form an apparently miscible, amorphous material. The glass transition temperature, T-g, of the latter is strongly depressed, at a rate of 7 degrees C/mol % LC-4,6A up to a molar ratio of 0.1, after which the T-g remains essentially constant. As supported by infrared analysis, the plasticization behavior is attributed to strong hydrogen bonding between the acid and pyridine moieties, which solubilizes the LC-4,6A molecules within the polymer matrix. When the solubility limit is reached, the excess small molecule solidifies into an ordered phase that is essentially identical to that of neat LC-4,6A. This phase can be modified by quenching from the melt, which freezes in a greater proportion of the acid-pyridine interactions and leads to incorporation into this phase of significant amounts of P4VP.
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页码:83 / 92
页数:10
相关论文
共 32 条
[1]  
ALEXANDER C, 1993, AM CHEM SOC POLYM PR, V34, P168
[2]  
[Anonymous], J PHYS ORSAY
[3]  
BAZUIN CG, 1994, MACROMOL SYMP, V84, P183
[4]   NOVEL LIQUID-CRYSTALLINE POLYMERIC MATERIALS VIA NONCOVALENT GRAFTING [J].
BAZUIN, CG ;
BRANDYS, FA .
CHEMISTRY OF MATERIALS, 1992, 4 (05) :970-972
[5]   TRANSITION-METAL COORDINATION IN POLYMER BLENDS AND MODEL SYSTEMS [J].
BELFIORE, LA ;
PIRES, ATN ;
WANG, YH ;
GRAHAM, H ;
UEDA, E .
MACROMOLECULES, 1992, 25 (05) :1411-1419
[6]   SELF-ASSEMBLY IN LIVING NEMATICS [J].
BLADON, P ;
GRIFFIN, AC .
MACROMOLECULES, 1993, 26 (24) :6604-6610
[7]  
BRANDRUP J, 1975, POLYM HDB, pCH3
[8]  
BRANDYS FA, 1993, ACS POLYM PREPR, V34, P186
[9]   PHASE-BEHAVIOR OF SOME ALPHA,OMEGA-DICARBOXYLIC ACIDS CONTAINING A MESOGENIC CORE [J].
CENTORE, R ;
ROVIELLO, A ;
SIRIGU, A .
LIQUID CRYSTALS, 1989, 6 (02) :175-183
[10]   LIQUID-CRYSTALLINE BEHAVIOR OF 4-(OMEGA-AMINOALKYLOXY)-4'-CYANOBIPHENYLS AND THEIR SIDE-CHAIN EPOXY POLYMERS [J].
CHIEN, LC ;
CADA, LG ;
XIE, L .
LIQUID CRYSTALS, 1992, 12 (05) :853-861