scholarly journals Glass transition temperatures and structures of multicomponent borate glasses: Influence of modifier cation field strengths

2016 ◽  
Vol 438 ◽  
pp. 1-6 ◽  
Author(s):  
Tsvetan Vassilev ◽  
Ivan Penkov ◽  
Christina Tzvetkova ◽  
Radost Pascova
Keyword(s):  
Glass Transition ◽  
Borate Glasses ◽  
Transition Temperatures ◽  
Glass Transition Temperatures ◽  
Modifier Cation ◽  
Field Strengths

scholarly journals Effect of Cooling Rate on the Structure of Sodium Borate Glasses

1993 ◽  
Vol 48 (4) ◽  
pp. 599-604 ◽  
Author(s):  
G. Ennas ◽  
A. Musinu ◽  
G. Piccaluga ◽  
G. Pinna
Keyword(s):  
Glass Transition ◽  
Coordination Shell ◽  
Distribution Functions ◽  
Sodium Borate ◽  
Borate Glasses ◽  
Transition Temperatures ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Glass Transition Temperatures ◽  
Density Values

Abstract Sodium borate glasses with two different compositions have been prepared using cooling rates in the range 7 • 10-3 ◦C/s-2 • 102 °C/s. Structural characterization has been carried out by X-ray diffraction, and glass transition temperatures have been measured by Differential Scanning Calorimetry. The samples exhibit slightly different density values and glass transition temperatures. However, radial distribution functions appear extremely similar and the sodium coordination shell does not change in going from fast to slowly quenched glasses, showing that the short and medium range order is not affected by thermal treatment.

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.

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