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Titolo:
EFFECT OF THE LENGTH OF N-ALKYL SIDE GROUPS ON THE MICROSTRUCTURE ANDSTEREOCHEMISTRY OF METHACRYLONITRILE ALKYL METHACRYLATE COPOLYMERS SYNTHESIZED BY FREE-RADICAL POLYMERIZATION
Autore:
VAZQUEZ B; VALERO M; GUZMAN GM; ROMAN JS;
Indirizzi:
CSIC,INST CIENCIA & TECHNOL POLIMEROS,JUAN DELACIERVA 3 E-28006 MADRID SPAIN CSIC,INST CIENCIA & TECHNOL POLIMEROS,JUAN DELACIERVA 3 E-28006 MADRID SPAIN UNIV PAIS VASCO,FAC QUIM,DPTO CIENCIA & TECNOL POLIMEROS SAN SEBASTIAN SPAIN
Titolo Testata:
Polymer
fascicolo: 8, volume: 34, anno: 1993,
pagine: 1755 - 1760
SICI:
0032-3861(1993)34:8<1755:EOTLON>2.0.ZU;2-4
Fonte:
ISI
Lingua:
ENG
Keywords:
NMR SPECTROSCOPY; SYNTHESIS; RADICAL POLYMERIZATION;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
16
Recensione:
Indirizzi per estratti:
Citazione:
B. Vazquez et al., "EFFECT OF THE LENGTH OF N-ALKYL SIDE GROUPS ON THE MICROSTRUCTURE ANDSTEREOCHEMISTRY OF METHACRYLONITRILE ALKYL METHACRYLATE COPOLYMERS SYNTHESIZED BY FREE-RADICAL POLYMERIZATION", Polymer, 34(8), 1993, pp. 1755-1760

Abstract

The microstructure of free-radical polymerized methacrylonitrile (N)-ethyl methacrylate (E) and N-butyl methacrylate (B) copolymers was studied by C-13 n.m.r. spectroscopy, and the results obtained were compared with those of N-methyl methacrylate (M) copolymers synthesized in similar experimental conditions. The distribution of monomer sequences and the stereochemical configuration of N-E and N-B copolymers were slightly different from that of N-M copolymers. The analysis of n.m.r. resonance signals provided a coisotacticity parameter sigma(ij) = sigma(ji) = sigma = 0.98 for both N-E and N-B systems, somewhat higher than that of the N-M copolymers (sigma = 0.87). This result was interpreted on the basis of strong dipolar interactions between the nitrile and carbonyl ester side groups of both kinds of monomeric units. It indicated the selectivity of a meso-meso relative stereochemical configuration for N or n-alkyl methacrylate centred sequences with two neighbouring comonomeric units of the second monomer, independently from the steric hindrance associated with the volume of the side alkyl substituent.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 06/07/20 alle ore 05:57:39