ISSN:
0021-8995
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
Copolymerization of elemental sulfur with styrene in the presence and absence of metallic sodium was studied at 120°C and 138°C. Propagation of the reaction was followed by gel permeation chromatography (GPC). Glass transition temperatures of all samples were obtained by differential scanning calorimetry (DSC). Reaction products were fractionated with a preparative-type GPC, and each fraction was characterized by DSC, vapor pressure osmometry, infrared spectrophotometry, and both proton and carbon-13 nuclear magnetic resonance spectrometry. Results indicate that the product is a true copolymer of styrene and sulfur. Kinetics of the copolymerization were studied using GPC to monitor styrene and sulfur concentrations. The initial rate of copolymerization (as followed by the consumption of styrene and sulfur) decreases with increasing initial styrene to sulfur ratio. From kinetic analyses, ratios of the rate constants of homo- and copolymerization were determined. Copolymerization of the reactants is more spontaneous than homopolymerization. The reactivity ratios obtained are 0.2 for styrene and 0.6 for sulfur.
Additional Material:
10 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/app.1984.070290418
