Unravelling Sequence Effect on Glass Transition Temperatures of Discrete Unconjugated Oligomers

2021 ◽  
pp. 2100666
Author(s):  
Ruizhe Liu ◽  
Chao Yang ◽  
Zixuan Huang ◽  
Rohan French ◽  
Zi Gu ◽  
...  
2011 ◽  
Vol 217-218 ◽  
pp. 1606-1610
Author(s):  
Dong Jiang ◽  
Xiao Ran Zhang ◽  
Yan Mei Ma ◽  
Cheng You Ma

A series of random polysulfone/polyethersulfone (PSF/PES) copolymers were synthesized by the polycondensation of 4, 4'-isopropylidendiphenol, 4, 4΄-dihyolroxy diphenyl sulfone and 4, 4'-dichlorodiphenyl sulfone in the presence of K2CO3. We obtained a series of copolymers by changing the molar ratio of 4, 4΄-dihyolroxy diphenyl sulfone and 4, 4'-isopropylidendiphenol (it was marked as the ratio of S:A). The copolymers have the similar solubility with polyethersulfone. They also have high glass transition temperatures (Tg: 199°C~229°C) and 5% weight loss temperatures (4, 4'-isopropylidendiphenol: 4, 4΄-dihyolroxy diphenyl sulfone=1:1, Td5=497°C). At the same time the elongation at break is much higher than that of PES, while the tensile strength is a little lower than that of PES.


1969 ◽  
Vol 47 (24) ◽  
pp. 4515-4520 ◽  
Author(s):  
Guy Perrault

The influence of prepolymer structure on glass transition temperatures (Tg) of cross-linked polyurethanes has been studied with polysebacates from a homologous family of N-substituted bis(2-hydroxyalkyl)amines. The tertiary amine segments have made it possible to study the effect of lengthening the side chains (C1–C18) and inserting gauche interactions in the polymeric chain. The results show that in this system, adding gauche interactions has more effect on Tg than lengthening the side chains. Each time a gauche interaction is introduced in the diol segments, Tg increases by 9 °C. Comparisons with other systems are also presented.


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