Polymerization of styrene to high degrees of conversion (up to 99.8%) was carried out. The obtained polystyrene was fractionated by distribution between two liquid phases and also by fractionating precipitation. Molecular weights of the fractions were determined and the molecular weight distribution
Molecular weights in polymerization as a function of conversion
โ Scribed by Litt, Morton
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 1970
- Tongue
- English
- Weight
- 405 KB
- Volume
- 8
- Category
- Article
- ISSN
- 0449-2978
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โฆ Synopsis
Abstract
A relatively novel method of calculating molecular weight changes and broadening during a polymerization is proposed. It differs from others in that the distribution is considered implicitly rather than explicitly. This allows direct use of kinetic rate equations in the derivation of weightโaverage and numberโaverage degree of polymerization etc.; the mathematics simplifies to simple integration rather than sums of complicated series. The method is illustrated by applying it to several cases. These range from various models where only monomer concentration changes, to where both monomer and initiator or monomer and chain transfer agent are changing. Cases previously unsolvable can now be handled.
๐ SIMILAR VOLUMES
## Abstract The copolymer compositions as a function of molecular weight for three poly(styreneโcoโvinyl stearate) copolymers of widely varying conversion were determined. A combined gel permeation chromatographyโinfrared spectroscopy method was used. Theoretical changes in copolymer composition we