RELAXATION STUDIES ON MODEL COMPOUNDS OF CYCLOHEXYL-BASED POLYACRYLATES

被引:11
作者
DIAZCALLEJA, R
RIANDE, E
ROMAN, JS
机构
[1] CSIC,INST CIENCIA & TECNOL POLIMEROS,E-28006 MADRID,SPAIN
[2] UNIV POLITECN VALENCIA,ESCUELA TECH SUPER INGN IND,TERMODINAM LAB,E-46071 VALENCIA,SPAIN
关键词
D O I
10.1021/j100181a073
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
The equilibrium and dynamic dielectric properties of cyclohexyl isobutyrate (CI) and cyclohexyl 2,4-dimethylglutarate (CG), model compounds of the repeating unit and the dimer of poly(cyclohexyl acrylate) (PCA), respectively, are determined. The results show that the dipole moment at 30-degrees-C of cyclohexyl 2,4-dimethylglutarate (2.84 D) is significantly higher than the value of this quantity (2.09 D) for its aromatic counterpart, phenyl 2,4-dimethylglutarate (PG), as a consequence of the strong preference for the high polarity t-pi,t-pi conformation in the racemic diad of the former compound. The dielectric relaxation spectrum of CI presents a relatively strong secondary relaxation, in comparison with that of the compounds with higher conformational versatility CG. Other esters such as PG and m-chlorophenyl 2,4-dimethylglutarate (MCPG) also exhibit weak secondary relaxations in their dielectric spectra. Attempts are made to explain at the molecular level the weak subglass absorptions of the esters based on 2,4-dimethylglutaric acid. The alpha relaxations in the model compounds are interpreted in terms of the coupling model.
引用
收藏
页码:931 / 936
页数:6
相关论文
共 31 条
[1]   CONFORMATIONAL ENERGIES AND RANDOM-COIL DIMENSIONS AND DIPOLE-MOMENTS OF POLYOXIDES CH3O[(CH2)YO]XCH3 [J].
ABE, A ;
MARK, JE .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1976, 98 (21) :6468-6476
[2]   RELAXATION PROCESSES IN CRYSTALLINE POLYMERS - MOLECULAR INTERPRETATION - A REVIEW [J].
BOYD, RH .
POLYMER, 1985, 26 (08) :1123-1133
[3]   SUBGLASS RELAXATION PROCESSES - DIELECTRIC-RELAXATION IN METHYL ACRYLATE ETHYLENE COPOLYMERS [J].
BUERGER, DE ;
BOYD, RH .
MACROMOLECULES, 1989, 22 (06) :2694-2699
[4]   SUBGLASS RELAXATION PROCESSES - DIELECTRIC-RELAXATION IN VINYL-ACETATE ETHYLENE COPOLYMERS [J].
BUERGER, DE ;
BOYD, RH .
MACROMOLECULES, 1989, 22 (06) :2699-2705
[5]   Dispersion and absorption in dielectrics I. Alternating current characteristics [J].
Cole, KS ;
Cole, RH .
JOURNAL OF CHEMICAL PHYSICS, 1941, 9 (04) :341-351
[6]   DIELECTRIC-RELAXATION STUDIES ON PHENYL AND CHLOROPHENYL ESTERS OF POLY(ACRYLIC ACID) [J].
DIAZCALLEJA, R ;
RIANDE, E ;
SANROMAN, J .
MACROMOLECULES, 1991, 24 (01) :264-269
[7]  
Frohlich H., 1959, THEORY DIELECTRICS
[8]  
GOLDSTEIN M, GLASS TRANSITION NAT
[9]   A PROPOSED SIMPLIFICATION IN THE PROCEDURE FOR COMPUTING ELECTRIC DIPOLE MOMENTS [J].
GUGGENHEIM, EA .
TRANSACTIONS OF THE FARADAY SOCIETY, 1949, 45 (08) :714-720
[10]   A COMPLEX PLANE REPRESENTATION OF DIELECTRIC AND MECHANICAL RELAXATION PROCESSES IN SOME POLYMERS [J].
HAVRILIA.S ;
NEGAMI, S .
POLYMER, 1967, 8 (04) :161-&