Partially Miscible Hybrids Made From Chlorinated Polyethylene and 2,2′-Methylene-Bis-(4-Methyl-6-Tert-Butyl Phenol)

2002 ◽  
Author(s):  
Jitao Liu ◽  
Jianyong Yu ◽  
Shanyuan Wang
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Damping Properties ◽  
Chlorinated Polyethylene ◽  
Damping Behavior ◽  
Wide Range ◽  
Partially Miscible ◽  
Butyl Phenol ◽  
Higher Temperature ◽  
Polar Polymer

Damping behaviors and miscibility between a polar polymer (CPE) and an organic small molecule (AO-18) are mainly discussed in this paper. It is well-known that mixing two partly compatible polymers can produce a material with a wide range of the glass transition temperature (Tg) and thus good damping behavior. In this paper, since CPE and AO-18 are partially miscible, adding AO-18 to CPE causes Tg of the mixture shifts to higher temperature, and the relaxation of AO-18 appears when AO-18 content is high in CPE/AO-18 alloy, similar to two partly compatible polymers. The damping properties around CPE glass transition are greatly improved compared with pure CPE, which can be attributed to the hydrogen bonds between CPE and AO-18 in CPE/AO-18 hybrids.

scholarly journals The Glass Transition Temperature and Temperature Dependence of Activation Energy of Viscous Flow of Ovalbumin

2016 ◽  
Vol 39 (1) ◽  
pp. 13-25
Author(s):  
Karol Monkos
Keyword(s):  
Activation Energy ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Viscous Flow ◽  
Solvent Interactions ◽  
Model Free ◽  
Free Volume Model ◽  
Wide Range ◽  
Different Temperatures

Abstract The paper presents the results of viscosity determinations on aqueous solutions of ovalbumin at a wide range of concentrations and at temperatures ranging from 5°C to 55°C. On the basis of these measurements and three models of viscosity for glass-forming liquids: Avramov’s model, free-volume model and power-law model, the activation energy of viscous flow for solutions and ovalbumin molecules, at different temperatures, was calculated. The obtained results show that activation energy monotonically decreases with increasing temperature both for solutions and ovalbumin molecules. The influence of the energy of translational heat motion, protein-protein and protein-solvent interactions, flexibility and hydrodynamic radius of ovalbumin on the rate of decrease in activation energy with temperature has been discussed. One of the parameters in the Avramov’s equation is the glass transition temperature Tg. It turns out that the Tg of ovalbumin solutions increases with increasing concentration. To obtain the glass transition temperature of the dry ovalbumin, a modified Gordon-Taylor equation is used. Thus determined the glass transition temperature for dry ovalbumin is equal to (231.8 ± 6.1) K.

Study of the Damping Properties of an CPE/ZKF/BPSR Organic Nanocomposites

2013 ◽  
Vol 278-280 ◽  
pp. 479-482
Author(s):  
Xin Bo Ding ◽  
Tao Liu ◽  
Bao Cheng Fu ◽  
Jian Han
Keyword(s):  
Critical Concentration ◽  
Three Dimensional ◽  
Peak Position ◽  
Loss Peak ◽  
Damping Properties ◽  
Chlorinated Polyethylene ◽  
High Loss ◽  
Hydrogen Bonding Interactions ◽  
Large Particles ◽  
Butyl Phenol

A novel organic nanocomposite consisting of chlorinated polyethylene (CPE), 2, 2’-methylene-bis-(4-methyl-6-cyclohexylphenol) (ZKF) and 4, 4’-thio-bis-(3-methyl-6-6tert-butyl- phenol) (BPSR) was prepared in this article. It was found that the presence of three-dimensional supra-molecular intermolecular hydrogen-bonding interactions was useful to not only compress and aggregate the molecularly dispersed ZKF and BPSR into nano-scaled particles, but also partially block the generated nanoparticles and effectively prevent them from over aggregation into large particles. The DMA results showed that there was a critical concentration for BPSR. When BPSR content was beyond the critical value, a novel loss peak was observed because of the formation of ZKF-BPSR-rich phase. These may imply that CPE/ZKF/BPSR nanocomposites possessing both high loss peak and controllable loss peak position can be more efficient in damping performance.

scholarly journals Predicting the influence of particle size on the glass transition temperature and viscosity of secondary organic material

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Markus Petters ◽  
Sabin Kasparoglu
Keyword(s):  
Particle Size ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Melting Point ◽  
Critical Role ◽  
Particle Diameter ◽  
Cloud Formation ◽  
Melting Point Depression ◽  
Wide Range

Abstract Atmospheric aerosols can assume liquid, amorphous semi-solid or glassy, and crystalline phase states. Particle phase state plays a critical role in understanding and predicting aerosol impacts on human health, visibility, cloud formation, and climate. Melting point depression increases with decreasing particle diameter and is predicted by the Gibbs–Thompson relationship. This work reviews existing data on the melting point depression to constrain a simple parameterization of the process. The parameter $$\xi $$ ξ describes the degree to which particle size lowers the melting point and is found to vary between 300 and 1800 K nm for a wide range of particle compositions. The parameterization is used together with existing frameworks for modeling the temperature and RH dependence of viscosity to predict the influence of particle size on the glass transition temperature and viscosity of secondary organic aerosol formed from the oxidation of $$\alpha $$ α -pinene. Literature data are broadly consistent with the predictions. The model predicts a sharp decrease in viscosity for particles less than 100 nm in diameter. It is computationally efficient and suitable for inclusion in models to evaluate the potential influence of the phase change on atmospheric processes. New experimental data of the size-dependence of particle viscosity for atmospheric aerosol mimics are needed to thoroughly validate the predictions.

Strain Dependence of the Glass Transition Point in Chlorinated Polyethylene Vulcanizates

1975 ◽  
Vol 48 (4) ◽  
pp. 623-630
Author(s):  
M. Naoki ◽  
T. Nose
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Physical Quantity ◽  
Inflection Point ◽  
Transition Point ◽  
Glass Transition Point ◽  
Chlorinated Polyethylene ◽  
Experimental Glass ◽  
Glass Forming ◽  
Direct Reflection

Abstract The experimental glass transition temperature observed as the inflection point in a certain physical quantity, Tgapp, changes not only with glass-forming conditions but also with the variables observed. Moreover the change of Tgapp with extension largely depends on the variables observed. These results indicate that Tgapp as determined by measurement of a certain physical quantity is not necessarily a direct reflection of the molecular mobility.

scholarly journals THERMAL STABILITY AND DAMPING PROPERTIES OF POLYURETHANE HYBRID MATERIAL BASED ON CASTOR OIL

2014 ◽  
Vol 5 (1) ◽  
Author(s):  
Jaroslava Budinski Simendić ◽  
Zoran Bjelović ◽  
Suzana Samaržija Jovanović ◽  
Vojislav Aleksić ◽  
Helena Valentova ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Castor Oil ◽  
Toluene Diisocyanate ◽  
Damping Capacity ◽  
Damping Properties ◽  
Degradation Temperature ◽  
Reactive Groups

This study reports the fabrication of environmentally friendly polyurethane materials using either 2,4-toluene diisocyanate or isophorone diisocyanate, castor oil as a polyol component, and TiO2 nanoparticles. Samples were prepared with stoichiometric balance of reactive groups. Dynamic viscoelastic properties of prepared samples were studied. The ratio of the loss component to the storage component (tanδ) was used as a measure of the material damping properties. The glass transition temperature was determined as a position of the tanδ curve maximum. The temperature range with tanδ > 0.3 was used to evaluate damping capacity of elastomers. Thermal stability of prepared samples was estimated by TGA method. It was assessed that PU based on aliphatic diisocyanate have higher thermal stability. Obtained values of the glass transition temperature and the starting degradation temperature are important for the application window of novel materials.

A study on the progress of mutarotation above and below the Tg and the relationship between constant rates and structural relaxation times

2017 ◽  
Vol 19 (31) ◽  
pp. 20949-20958 ◽  
Author(s):  
K. Wolnica ◽  
M. Dulski ◽  
E. Kaminska ◽  
A. Cecotka ◽  
M. Tarnacka ◽  
...  
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Structural Relaxation ◽  
Relaxation Times ◽  
Ftir Studies ◽  
Wide Range ◽  
The Relationship

Comprehensive FTIR studies on the progress of mutarotation in d-fructose mixed with maltitol have been carried out over a wide range of temperatures, both above and below the glass transition temperature Tg.

The damping properties of dealloyed porous copper and its PMMA composite

1994 ◽  
Vol 9 (11) ◽  
pp. 2884-2890
Author(s):  
Un-Sig Min ◽  
James C.M. Li
Keyword(s):  
Activation Energy ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Apparent Activation Energy ◽  
Volume Fraction ◽  
Pure Copper ◽  
Damping Properties ◽  
Young’S Moduli ◽  
Porous Copper

Incramute Cu-Mn alloys were dealloyed to remove Mn by selective electrolytic separation. The porous dealloyed specimens were compressed at 0.17-14 GPa, resulting in densities of 55-88% of the density of pure copper. Some porous copper specimens before compression were soaked in a mixture of monomer (MMA) and the initiator (AIBN), compressed, and then polymerized by heating. Young's moduli of both the dealloyed porous copper and its PMMA composite were found to decrease exponentially with porosity and volume fraction of PMMA, respectively. The apparent activation energy for damping of Cu-PMMA composite near the glass transition temperature of PMMA was found to increase with decreasing volume fraction of PMMA.

Melt-Processable Acrylonitrile-Methacrylate-Dimethyl Maleate Terpolymers and Fibers

2014 ◽  
Vol 487 ◽  
pp. 121-126 ◽  
Author(s):  
Tian Yu Wang ◽  
Xing Xiang Zhang ◽  
Na Han
Keyword(s):  
Weight Loss ◽  
Tensile Strength ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Cross Sections ◽  
Molar Ratio ◽  
Molar Ratios ◽  
Dimethyl Maleate ◽  
Higher Temperature

A series of acrylonitrile (AN)-methacrylate (MA)-dimethyl maleate (DMM) terpolymers with different molar ratios were fabricated by emulsion polymerization. The feeding ratio agrees well with the composition of AN-MA-DMM terpolymer. With increasing the molar ratio of DMM in terpolymer, glass transition temperature (Tg) increases to higher temperature at first and then decreases. Tgdrops to the lowest value-78.6 °C when the feeding ratio is 85/13/2 mol%. The melting temperature (Tm) of 85/11/4 AN-MA-DMM terpolymer is the lowest at-137.2 °C, while its resistant temperature (5 wt% weight loss, T0.05) rises up to the highest value, -314.9 °C. DMM plays an important role in improving the melt flowability of PAN based copolymer. The cross sections of 85/14/1 AN-MA-DMM fiber are compact and the outer surfaces of the fiber are smooth. Tensile strength of AN-MA-DMM fiber is 3.4 cN/dtex.

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