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The glass transition temperature for non-gaussian network polymers

 

作者: JohnM. Charlesworth,  

 

期刊: Journal of Macromolecular Science, Part B  (Taylor Available online 1987)
卷期: Volume 26, issue 1  

页码: 105-133

 

ISSN:0022-2348

 

年代: 1987

 

DOI:10.1080/00222348708248061

 

出版商: Taylor & Francis Group

 

数据来源: Taylor

 

摘要:

The influence of crosslinking and copolymerization on the glass transition temperature, Tg, of a range of diepoxide-diamine network polymers is examined. It is established that existing theories relating Tgto the level of crosslinking are inexact above a crosslink concentration of approximately 0.5 mole dm−3. To account for this deviation, the thermodynamic treatment of the glass transition is modified to take into consideration a non-Gaussian spatial distribution of chain segments and the steric restrictions upon movement of segments in the vicinity of junctions. The resulting equation-involving two empirical parameters, and the number of rotatable bonds between junctions—is shown to adequately explain data for the diglycidylethers of bisphenol A and butanediol, crosslinked with benzidine/aniline and 1,8-oc-tanediamine/n-butylamine mixtures. The behavior of networks prepared from α, ω-alkyldiamines containing from 2 to 36 methylene units can be predicted provided it is assumed that

 

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