Free-radical polymerization of styrene withp-nitrobenzyl triphenyl phosphonium ylide as an initiator

Autor:	Kiran Prajapati, Anuradha Varshney
Rok vydání:	2005
Předmět:	chemistry.chemical_classification Polymers and Plastics Organic Chemistry Radical polymerization Solution polymerization Carbon-13 NMR Styrene chemistry.chemical_compound chemistry Polymerization Ylide Tacticity Polymer chemistry Materials Chemistry Proton NMR
Zdroj:	Journal of Polymer Science Part A: Polymer Chemistry. 43:6524-6533
ISSN:	1099-0518 0887-624X
DOI:	10.1002/pola.20708
Popis:	The free-radical polymerization of styrene with p-nitrobenzyl triphenyl phosphonium ylide as an initiator in dioxane at 80 ± 1 °C in a dilatometer under a nitrogen atmosphere for 150 min resulted in a syndiotactic polymer, as evidenced by IR, 1H NMR, and 13C NMR spectroscopy. A 1H NMR spectrum showed methylene protons as triplets; 13C NMR signals of the phenyl ipso carbons were used for the determination of the tacticity. The system followed ideal kinetics. Gel permeation chromatography data were used evaluate the weight-average molecular weight. The overall activation energy was 47 kJ/mol. Electron spin resonance spectroscopy confirmed the initiation by the phenyl radical obtained by the dissociation of the ylide and the free-radical mode of polymerization. Differential scanning calorimetry studies showed the glass-transition temperature of the polymer to be 342 K. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 6524–6533, 2005
Databáze:	OpenAIRE
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