Facile synthesis of stereoregular carbon fiber precursor polymers by template assisted solid phase polymerization

Krishnan, GS and Burkanudeen, A and Murali, N and Phadnis, H (2012) Facile synthesis of stereoregular carbon fiber precursor polymers by template assisted solid phase polymerization. eXPRESS Polymer Letters, 6 (9). pp. 729-738. ISSN 1788-618X

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Abstract

Predominantly isotactic stereoregular polyacrylonitrile copolymers (PAC) were prepared by solid phase polymerization techniques using hexagonal crystalline metal salts as template compounds. Stereoregular distributions of the prepared polymer were studied using high resolution 13C nuclear magnetic resonance spectroscopy (13C NMR) spectra. The extent of isotacticity was directly determined from the peak intensity of the methine carbon (CH). The triad tacticity from the intensities of methine carbon peaks were examined by statistical methods. It was found that the PAC was predominantly isotactic in stereoregularity, and its sequence distribution obeys Bernoulli statistics. The optimum polymerization conditions ensuring isotactic content over 50% were disclosed experimentally. The chemical composition of PAC was confirmed with 1H NMR data. The obtained polyacrylonitrile copolymers were also characterized for molecular parameters such as viscosity average molecular weight (Mv), number average molecular weight (Mn), weight average molecular weight (Mw) and polydispersity index.

Item Type:	Article
Additional Information:	Copyright to this article belongs to M/s. eXPRESS Polymer
Uncontrolled Keywords:	Polymer synthesis;Polyacrylonitrile copolymer;NMR; Stereoregularity;Molecular weight distribution
Subjects:	CHEMISTRY AND MATERIALS > Chemistry and Materials (General)
Depositing User:	Ms. Alphones Mary
Date Deposited:	16 Sep 2013 04:35
Last Modified:	16 Sep 2013 04:35
URI:	http://nal-ir.nal.res.in/id/eprint/11763

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