Glass transition temperatures in the system calcium chloride-water-dimethylsulphoxide

1983 ◽  
Vol 48 (6) ◽  
pp. 1558-1563
Author(s):  
Jarmila Malá ◽  
Ivo Sláma
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Mole Fraction ◽  
Mixed Solvent ◽  
Transition Temperatures ◽  
Composition Region ◽  
Glass Transition Temperatures ◽  
Glass Forming ◽  
Dmso System ◽  
Chloride Water

The glass-forming composition region of the CaCl2-H2O-DMSO system has been established, and the glass transition temperatures of the mixtures have been determined as a function of the CaCl2 content at a constant DMSO mole fraction in the mixed solvent. The dependence of the glass transition temperature on the CaCl2 mole fraction at a constant mole fraction of DMSO in the mixed solvent can be described by a linear relationship.

Glass transition temperatures and glass-forming region of the system lithium chloride-dimethyl sulphoxide-water

1985 ◽  
Vol 50 (5) ◽  
pp. 1161-1167
Author(s):  
Jarmila Malá ◽  
Ivo Sláma
Keyword(s):  
Glass Transition ◽  
Mixed Solvent ◽  
Solid Phase ◽  
Aqueous System ◽  
Transition Temperatures ◽  
Constant Composition ◽  
Glass Transition Temperatures ◽  
Glass Forming ◽  
Complicated Pattern ◽  
Phase Nucleation

Glass transition temperatures (Tg) of the system LiCl-DMSO-H2O have been measured. A small addition of DMSO to the binary aqueous system removes its unusual variation of Tg with salt concentration. The concentration dependence of Tg of the ternary system at a constant composition of the mixed solvent can be described by a linear equation. The variation in Tg with the mixed solvent composition at constant LiCl concentration follows a complicated pattern which cannot be described by commonly used relations. The boundaries of glass-forming region are discussed in terms of the effect of a change in solution composition on the induction period of equilibrium solid phase nucleation.

Properties and Structure of Elastomers

1966 ◽  
Vol 39 (4) ◽  
pp. 881-896 ◽  
Author(s):  
Joginder Lal ◽  
Kenneth W. Scott
Keyword(s):  
Tensile Strength ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Alkyl Group ◽  
Side Chain ◽  
Transition Temperatures ◽  
Glass Transition Temperatures ◽  
Dynamic Mechanical ◽  
Alkyl Ethers

Abstract The glass transition temperatures of high molecular weight poly (vinyl n-alkyl ethers) decrease with increasing length of the n-alkyl group. On lengthening the n-alkyl group, 14 per cent of the specific volume increase is free volume. Branching or substitution in the alkyl group of the polymer increases the Tg value. A comparison of poly (vinyl n-alkyl ethers) and polymers of normal α-olefins shows that an ether group and a methylene group in the side chain are equivalent in influencing the glass transition temperature. We have varied systematically the side chain alkyl group in poly (vinyl alkyl ethers) and evaluated at 3 different temperatures the influence of these variations on the dynamic properties of the vulcanizates of these polymers. The relative position of the curves, relating dynamic resilience to dynamic modulus of these polymers, is generally in the order of their glass transition temperatures. The dynamic mechanical property data on poly (vinyl n-pentyl ether) and poly (vinyl 2-ethylhexyl ether), which have the same glass transition temperature, fall on a common curve characteristic of the temperature of measurement. Apparently, the Tg is a major factor in correlating the dynamic mechanical behavior of these elastomers. The size and shape of the alkyl group appear to be reflected primarily in their effect on the Tg. Polysulfidic crosslinks are not essential for the attainment of high tensile strength in natural rubber vulcanizates cured with a sulfur-diphenylguanidine system. Data for the samples which had lost significant amounts of polysulfidic crosslinks by reaction with triphenylphosphine fitted a curve of tensile strength as a function of 300 per cent modulus for the control samples.

Well-defined high refractive index poly(monothiocarbonate) with tunable Abbe's numbers and glass-transition temperatures via terpolymerization

2015 ◽  
Vol 6 (27) ◽  
pp. 4978-4983 ◽  
Author(s):  
Ming Luo ◽  
Xing-Hong Zhang ◽  
Bin-Yang Du ◽  
Qi Wang ◽  
Zhi-Qiang Fan
Keyword(s):  
Refractive Index ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Propylene Oxide ◽  
High Refractive Index ◽  
Transition Temperatures ◽  
Cyclohexene Oxide ◽  
Glass Transition Temperatures

Poly(monothiocarbonate) with tunable Abbe's number and glass-transition temperature is synthesized via terpolymerization of COS with propylene oxide and cyclohexene oxide.

Naphthalene-based poly(aryl ether)s. II. Synthesis and characterization of poly(ether ketone)s containing two 1,4-naphthylene moieties in the repeat unit

1997 ◽  
Vol 75 (10) ◽  
pp. 1346-1353 ◽  
Author(s):  
Zhi Yuan Wang ◽  
Peter W. Broughton
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Repeat Unit ◽  
Synthesis And Characterization ◽  
Transition Temperatures ◽  
Aryl Ether ◽  
Glass Transition Temperatures ◽  
Phenyl Sulfone ◽  
Ether Ketone

Two new monomers, 4-chloro-1-(4′-fluoro-1-naphthoyl)naphthalene and 1,4-bis(4′-fluoro-1′-naphthoyl)benzene, have been synthesized and polymerized with four different bisphenols to give two series of the naphthalene-based poly(ether ketone)s that are analogous to commercial PEEK and PEEKK. The effect of the introduction of one or two 1,4-naphthylene moieties, in the backbone of the repeat unit, on the glass transition temperatures has been studied. The glass transition temperatures usually increased by 20–45 °C upon replacing one 1,4-phenylene with one 1,4-naphthylene moiety. All new poly (ether ketone)s prepared in tetramethylene sulfone were amorphous, with the glass transition temperatures in a range of 212–273 °C. The polymer produced from 1,4-bis(4′-fluoro-1′-naphthoyl)benzene and 1,4-hydroquinone in phenyl sulfone as a solvent at 300 °C showed semicrystalline properties with a melting temperature of 310 °C. Keywords: naphthalene, poly(ether ketone)s, synthesis, characterization, glass transition temperature.

scholarly journals High Glass Transition Temperature Fluoropolymers for Hydrophobic Surface Coatings via RAFT Copolymerization

2016 ◽  
Vol 69 (7) ◽  
pp. 725 ◽  
Author(s):  
Molly Rowe ◽  
Guo Hui Teo ◽  
James Horne ◽  
Omar Al-Khayat ◽  
Chiara Neto ◽  
...  
Keyword(s):  
Thin Films ◽  
Contact Angle ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Surface Coatings ◽  
Transition Temperatures ◽  
High Glass Transition Temperature ◽  
Glass Transition Temperatures ◽  
Hydrophobic Polymers

The preparation of polymer thin films or surface coatings that display a static water contact angle >95° often requires hierarchical roughness features or surface functionalization steps. In addition, inherently hydrophobic polymers such as fluoropolymers often possess low glass transition temperatures, reducing their application where thermal stability is required. Herein, the first reported synthesis of 2,3,4,5,6-pentafluorostyrene (PFS) and N-phenylmaleimide (NMI) via reversible addition–fragmentation chain-transfer (RAFT)-mediated free radical polymerization is presented, with a view towards the preparation of inherently hydrophobic polymers with a high glass transition temperature. A suite of copolymers were prepared and characterized, and owing to the inherent rigidity of the maleimide group in the polymer backbone and π–π interactions between adjacent PFS and NMI groups, very high glass transition temperatures were achieved (up to 180°C). The copolymerization of N-pentafluorophenylmaleimide was also performed, also resulting in extremely high glass transition temperature copolymers; however, these polymers did not exhibit characteristics of being under RAFT control. Thin films of PFS-NMI copolymers exhibited a static contact angle ~100°, essentially independent of the amount of NMI incorporated into the polymer.

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