The temperature and concentration dependence of viscosity and the concentration dependence of glass transition temperature for the system calcium nitrate-potassium nitrate-water

1981 ◽  
Vol 46 (9) ◽  
pp. 2149-2157 ◽  
Author(s):  
Mojmír Skokánek ◽  
Jarmila Malá ◽  
Ivo Sláma
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Concentration Dependence ◽  
Mole Fraction ◽  
Potassium Salt ◽  
Calcium Nitrate ◽  
Potassium Nitrate ◽  
Empirical Equations ◽  
Temperature Range

The temperature and concentration dependence of viscosity of the system calcium nitrate-potassium nitrate-water was studied in the temperature range -20 to +75 °C for concentrations given by ionic fractions of the potassium salt of 0.1, 0.2, 0.3, 0.4, and 0.5. The mole fraction of the salts was within the range 0.047 to 0.238. The temperature and concentration dependence of viscosity has been correlated with empirical equations. An equation describing the temperature and concentration dependence of viscosity has been proposed on the basis of the variation of glass transition temperature with concentration.

Glass transition temperature of calcium nitrate-potassium nitrate-water system

1980 ◽  
Vol 45 (7) ◽  
pp. 1896-1902 ◽  
Author(s):  
Jarmila Malá ◽  
Ivo Sláma
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Linear Function ◽  
Calcium Nitrate ◽  
Water System ◽  
Potassium Nitrate ◽  
Concentration Region ◽  
Hydrated Calcium ◽  
Nitrate Solutions

The glass-formig concentration region of the calcium nitrate-potassium nitrate-water system was determined. The glass transition temperature can be in the studied region approximated by a linear function of the salt concentrations. A comparison of the properties of the studied system with the hydrated calcium nitrate and chloride mixture revealed important differences in the effect of different salts on the undercoolability of aqueous calcium nitrate solutions.

Study on the Crystallization Activation Energy of Poly (L-lactic acid) Nucleated with P-tert-butylcalix[8]arene

2018 ◽  
Vol 26 (2) ◽  
pp. 169-175
Author(s):  
Yaoqi Shi ◽  
Liang Wen ◽  
Zhong Xin
Keyword(s):  
Activation Energy ◽  
Lactic Acid ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Crystallization Temperature ◽  
Nucleating Agent ◽  
Crystallization Activation Energy ◽  
Temperature Range ◽  
Chain Mobility

The crystallization activation energy (Δ E) of a polymer comprises the nucleation activation energy Δ F and the transport activation energy Δ E*. In this paper, the Δ E of poly (L-lactic acid) (PLLA) nucleated with nucleating agent p- tert-butylcalix[8]arene (tBC8) was calculated. The results showed that the Δ E of nucleated PLLA was 165.97 kJ/mol, which is higher than that of pure PLLA. The reason why Δ E of PLLA increased when incorporating nucleating agent was studied. The increment of glass transition temperature ( Tg) for nucleated PLLA revealed that the polymer chain mobility was restricted by tBC8, which was considered as the reason for the increase of Δ E*. Further, polyethylene glycol (PEG) was added to improve the chain mobility, thus eliminated the variation of the transport activation energy Δ E* caused by tBC8. Then the effect of the increment of crystallization temperature range on the increase of Δ F was also taken into consideration. It was concluded that both decreasing the mobility of chain segments and increasing the crystallization temperature range caused an increase of Δ E for PLLA/tBC8.

The Effect of Thermal History on Porcelain Expansion Behavior

1989 ◽  
Vol 68 (9) ◽  
pp. 1313-1315 ◽  
Author(s):  
C.W. Fairhurst ◽  
D.T. Hashinger ◽  
S.W. Twiggs
Keyword(s):  
Thermal Expansion ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Heating Rate ◽  
Room Temperature ◽  
Heating Rates ◽  
Thermal Expansion Data ◽  
Temperature Range ◽  
Expansion Behavior

Porcelain-fused-to-metal restorations are fired several hundred degrees above the glass-transition temperature and cooled rapidly through the glass-transition temperature range. Thermal expansion data from room temperature to above the glass-transition temperature range are important for the thermal expansion of the porcelain to be matched to the alloy. The effect of heating rate during measurement of thermal expansion was determined for NBS SRM 710 glass and four commercial opaque and body porcelain products. Thermal expansion data were obtained at heating rates of from 3 to 30°C/min after the porcelain was cooled at the same rate. By use of the Moynihan equation (where Tg systematically increases in temperature with an increase in cooling/heating rate), the glass-transition temperatures (Tg) derived from these data were shown to be related to the heating rate.

Salt-Concentration Dependence of the Glass Transition Temperature in PEO–NaI and PEO–LiTFSI Polymer Electrolytes

2013 ◽  
Vol 46 (21) ◽  
pp. 8580-8588 ◽  
Author(s):  
Nicolaas A. Stolwijk ◽  
Christian Heddier ◽  
Manuel Reschke ◽  
Manfred Wiencierz ◽  
Joachim Bokeloh ◽  
...  
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Concentration Dependence ◽  
Salt Concentration ◽  
Polymer Electrolytes
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