Impact of cyclic topology: odd–even glass transition temperatures and fluorescence quantum yields in molecularly-defined macrocycles

2017 ◽  
Vol 8 (17) ◽  
pp. 2686-2692 ◽  
Author(s):  
Kun Li ◽  
Ganquan Jiang ◽  
Feng Zhou ◽  
Lishan Li ◽  
Zhengbiao Zhang ◽  
...  
Keyword(s):  
Glass Transition ◽  
Intermolecular Interactions ◽  
Topological Structure ◽  
Quantum Yields ◽  
Transition Temperatures ◽  
Glass Transition Temperatures ◽  
Fluorescence Quantum Yields

The topological structure of cyclic-TPEn+1 (n = 1–6) induces odd–even effects on the Tg and AIE behavior, arising from the alternation of intermolecular interactions.

Properties of Random PSF/PES Copolymers as High-Performance Polymers

2011 ◽  
Vol 217-218 ◽  
pp. 1606-1610
Author(s):  
Dong Jiang ◽  
Xiao Ran Zhang ◽  
Yan Mei Ma ◽  
Cheng You Ma
Keyword(s):  
Weight Loss ◽  
Tensile Strength ◽  
Glass Transition ◽  
High Performance ◽  
Molar Ratio ◽  
Transition Temperatures ◽  
Elongation At Break ◽  
Glass Transition Temperatures ◽  
High Performance Polymers ◽  
Diphenyl Sulfone

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.

Influence de la structure du prépolymère sur la température de transition vitreuse de polyuréthanes réticulés

1969 ◽  
Vol 47 (24) ◽  
pp. 4515-4520 ◽  
Author(s):  
Guy Perrault
Keyword(s):  
Glass Transition ◽  
Tertiary Amine ◽  
Polymeric Chain ◽  
Side Chains ◽  
Transition Temperatures ◽  
Glass Transition Temperatures

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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