Dynamic properties of concentrated solutions above the glass transition temperature

1992 ◽  
Vol 96 (8) ◽  
pp. 6274-6280 ◽  
Author(s):  
Wyn Brown ◽  
Robert M. Johnsen ◽  
Cestmir Konak ◽  
Ladislav Dvoranek
2016 ◽  
Vol 113 (19) ◽  
pp. 5195-5200 ◽  
Author(s):  
Davide Michieletto ◽  
Matthew S. Turner

The static and dynamic properties of ring polymers in concentrated solutions remains one of the last deep unsolved questions in polymer physics. At the same time, the nature of the glass transition in polymeric systems is also not well understood. In this work, we study a novel glass transition in systems made of circular polymers by exploiting the topological constraints that are conjectured to populate concentrated solutions of rings. We show that such rings strongly interpenetrate through one another, generating an extensive network of topological interactions that dramatically affects their dynamics. We show that a kinetically arrested state can be induced by randomly pinning a small fraction of the rings. This occurs well above the classical glass transition temperature at which microscopic mobility is lost. Our work both demonstrates the existence of long-lived inter-ring penetrations and realizes a novel, topologically induced, glass transition.


2018 ◽  
Vol 928 ◽  
pp. 9-13
Author(s):  
Wen Fei Wang ◽  
Chang Fei Hu ◽  
Chun Qing Zhang ◽  
Wei Cheng ◽  
Bing Wang

A new type of viscoelastic vibration damping rubber matrix, styrene-butadiene block copolymer with designed molecular weight, unit sequence, mass ratio of styrene/butadiene and content of bound styrene synthesized through anionic solution polymerization method with more excellent damping properties than the current commercialized SBR is exhibited. In addition, the glass transition temperature (Tg) of the new type of SBR can be tunable to the suitable temperature region according to the application requirements. In this paper, we put the emphasis on the synthesis and properties characterization of this new type material, and try to provide a new method to fabricate a viscoelastic damping material (VDM) with tunable Tg and excellent dynamic mechanical properties usable for applications in the field of vibration reduction industry.


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