The concept of effective crosslinking density proposed by Scanlan is extended to heterogeneously crosslinking polymer. A kinetic-statistical model of effective crosslinking density of the gel is developed in free-radical heterogeneously crosslinking polymerization. The model is applied to the vinyl
Modelling of crosslinking and cyclization in free-radical copolymerization of vinyl/divinyl monomers
β Scribed by Zhu, S. ;Hamielec, A. E. ;Pelton, R. H.
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 1993
- Weight
- 919 KB
- Volume
- 2
- Category
- Article
- ISSN
- 1018-5054
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β¦ Synopsis
Abstract
The TobitaβHamielec kinetic model of the crosslink density distribution is further elaborated and extended to incorporate divinyl loop formation. Divinyl loop formation, primary and secondary cyclization, and their effects on the elastically effective crosslink density distribution are extensively examined as a function of cyclization parameters and double bond reactivities. Under conditions of equal double bond rectivity and negligible cyclization, primary chains born at different conversions have the same crosslink density. The variance of the crosslink density distribution is mainly due to unequal reactivities of double bonds and secondary cyclization. Divinyl loop formation and primary cyclization contribute neither to gelation nor to network elasticity and have an insignificant effect on the variance of the crosslink density distribution.
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Republic of China ## SYNOPSIS A general model of the gel/sol partition in the free-radical copolymerization of vinyl/divinyl monomers was developed, combining the statistical and kinetic modeling. It is emphasized that properties of the primary chains born at some conversion are effected by their
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