Conformation of polymethyl methacrylate stereochemical isomers in non-interacting media

Autor:	Ichiro Sakurada, Osamu Yoshizaki, Akio Nakajima, Katsuhiko Nakamae
Rok vydání:	1962
Předmět:	Solvent system Colloid and Surface Chemistry Materials science Polymers and Plastics Polymethyl methacrylate Molecular dimensions Tacticity Polymer chemistry Materials Chemistry Thermodynamics Physical and Theoretical Chemistry
Zdroj:	Kolloid-Zeitschrift & Zeitschrift für Polymere. 186:41-50
ISSN:	1435-1536 0303-402X
DOI:	10.1007/bf01797952
Popis:	Isotactic, syndiotactic and atactic polymethyl methacrylate were prepared by proper methods and fractionated. With these fractions, the theta temperatures and the entropy parameters,ψ 1, were determined in four solvent systems from the precipitation measurements, and the intrinsic viscosities were compared between isotactic and atactic modifications at the theta temperatures. It was pointed out that the unperturbed dimension and the entropy parameter of the isotactic species, respectively, are larger than those of the atactic species. Also, it was found that the temperature dependence of the unperturbed dimensions is quite different for both isomeric forms. The molecular dimensions of the isotactic modification in non-interacting media were interpreted in accordance with the semi-flexible chain treatment ofFlory.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::25cf1b51d978b28937287530cfc2ae36 https://doi.org/10.1007/bf01797952 Zobrazit plný text záznamu Full text from SpringerLink