scholarly journals Competition between Scission and Cross-linking Processes in the Thermal Degradation of a Polycarbonate

Nature ◽  
1965 ◽  
Vol 206 (4982) ◽  
pp. 397-397 ◽  
Author(s):  
A. DAVIS ◽  
J. H. GOLDEN
Keyword(s):  
Thermal Degradation ◽  
Cross Linking

scholarly journals Effect of neutralization and cross-linking on the thermal degradation of chitosan electrospun membranes

2014 ◽  
Vol 117 (1) ◽  
pp. 123-130 ◽  
Author(s):  
D. M. Correia ◽  
M. A. Gámiz-González ◽  
G. Botelho ◽  
A. Vidaurre ◽  
J. L. Gomez Ribelles ◽  
...  
Keyword(s):  
Thermal Degradation ◽  
Cross Linking ◽  
Electrospun Membranes

Preventing thermal degradation of PVC insulation by mixtures of cross‐linking agents and antioxidants

2019 ◽  
Vol 137 (24) ◽  
pp. 48816 ◽  
Author(s):  
Witold Brostow ◽  
Nathalie Hnatchuk ◽  
Taehwan Kim
Keyword(s):  
Thermal Degradation ◽  
Cross Linking

Smearing of Vulcanized Rubber

1955 ◽  
Vol 28 (2) ◽  
pp. 508-518 ◽  
Author(s):  
S. D. Gehman ◽  
C. S. Wilkinson ◽  
R. D. Daniels
Keyword(s):  
Melting Point ◽  
Thermal Degradation ◽  
Natural Rubber ◽  
Sulfur Compound ◽  
Important Variable ◽  
Cross Linking ◽  
Curing Agent ◽  
Point Bar ◽  
Tetramethylthiuram Disulfide ◽  
Vulcanized Rubber

Abstract The surface heating which occurs at the interface of rubber sliding under a load may be part of the mechanism of abrasion, especially under severe conditions. Removal of rubber by thermal degradation and a smearing process occurs if the rubber attains sufficiently high localized temperatures. A procedure, using a melting point bar, was developed for measuring the temperature at which smearing occurred for rubber vulcanizates. Smear points reproducible to about ±2° F were measured. The effect of compounding variables on the smear point was investigated. The most important variable in this category was the vulcanization system, probably inasmuch as it determined the type of cross-linking. The presence of free sulfur within the rubber also tended to increase the smear temperature. Highest smear points were obtained with mercaptobenzothiazole-tetramethylthiuram disulfide mixtures, and for a non-sulfur compound using p-quinone-dioxime as the curing agent. The highest smear point observed for natural rubber was 475° F, obtained with this system. GR-S tread compounds showed no smearing even at 560° F, which was as high as could be obtained with the apparatus used. The resistance to smearing of GR-S may be an important factor in explaining its superiority in road wear under severe conditions. Laboratory abrasion experiments were performed to illustrate the effect of smearing on the relative abrasion loss of GR-S and natural-rubber tread compounds.

PILCs as Water-Transmitting Material and Application in Planting Trees in Drought Areas

2011 ◽  
Vol 685 ◽  
pp. 239-245
Author(s):  
Zeng Zhi Zhang ◽  
Bo Tao Wang ◽  
Shuang Zhou
Keyword(s):  
Survival Rate ◽  
Thermal Degradation ◽  
Soil Layer ◽  
Cross Linking ◽  
Capillary Water ◽  
Water Conductivity ◽  
Conductivity Property ◽  
Dry Soil ◽  
Porosity Analysis ◽  
Structural Aspects

Clay-based water-transmitting materials were proposed in order to solve the problems of dry soil layer and watering during forest planting in drought areas. The pillared interlayered clay was prepared in the presence of primary bentonite. The conductivity property was investigated under various conditions of cross-linking agent ratio. The structural aspects and thermal degradation of composites were also studied by means of XRD, TG and porosity analysis. The results indicated that pillared clays modified by Al cross-linking agent exhibit higher water conductivity properties remarkably. Larger specific surface area, more pores and complicated pore structures play vital roles in the enhancement of the conductivity property. This kind of material can obviously elevate capillary water upward from subsurface aquifer to the roots of saplings in drought areas so as to improve the survival rate of the saplings.

Cross-linking and gel formation in the thermal degradation of PVC

1976 ◽  
Vol 5 (3) ◽  
pp. 309-315 ◽  
Author(s):  
T. T. Nagy ◽  
B. Turcsányi ◽  
T. Kelen ◽  
F. Tüdős
Keyword(s):  
Thermal Degradation ◽  
Cross Linking ◽  
Gel Formation

scholarly journals Degradation Studies Realized on Natural Rubber and Plasticized Potato Starch Based Eco-Composites Obtained by Peroxide Cross-Linking

2018 ◽  
Vol 19 (10) ◽  
pp. 2862 ◽  
Author(s):  
Elena Manaila ◽  
Maria Stelescu ◽  
Gabriela Craciun
Keyword(s):  
Thermal Degradation ◽  
Mechanical Characteristics ◽  
Temperate Climate ◽  
Cross Linking ◽  
Natural Ageing ◽  
Cross Link ◽  
Link Density ◽  
Cross Link Density ◽  
Plasticized Starch ◽  
One Year

The obtaining and characterization of some environmental-friendly composites that are based on natural rubber and plasticized starch, as filler, are presented. These were obtained by peroxide cross-linking in the presence of a polyfunctional monomer used here as cross-linking co-agent, trimethylolpropane trimethacrylate. The influence of plasticized starch amount on the composites physical and mechanical characteristics, gel fraction and cross-link density, water uptake, structure and morphology before and after accelerated (thermal) degradation, and natural (for one year in temperate climate) ageing, was studied. Differences of two orders of magnitude between the degradation/aging methods were registered in the case of some mechanical characteristics, by increasing the plasticized starch amount. The cross-link density, water uptake and mass loss were also significant affected by the plasticized starch amount increasing and exposing for one year to natural ageing in temperate climate. Based on the results of Fourier Transform Infrared Spectroscopy (FTIR) and cross-link density measurements, reaction mechanisms attributed to degradation induced by accelerated and natural ageing were done. SEM micrographs have confirmed in addition that by incorporating a quantity of hydrophilic starch amount over 20 phr and by exposing the composites to natural ageing, and then degradability can be enhanced by comparing with thermal degradation.

Development of technology of polysulfone production for 3D printing

2017 ◽  
Vol 29 (6) ◽  
pp. 724-729 ◽  
Author(s):  
Azamat A Zhansitov ◽  
Svetlana Y Khashirova ◽  
Azamat L Slonov ◽  
Zhanna I Kurdanova ◽  
Albert S Shabaev ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
3D Printing ◽  
Thermal Degradation ◽  
Strength Properties ◽  
Cross Linking ◽  
Molten Polymer ◽  
Chain Rigidity

This article discusses the results of experimental research on the synthesis of polyether sulfones and the molten polymer filament layering 3-D printing technology. The regularities of influence of the polycondensation conditions in the synthesis of polyphenylene sulfone on the processes of cross-linking, thermal degradation of the polymer at processing temperatures, and 3-D printing were revealed. It is shown that introduction of cardo fragments increases the glass transition temperature and heat resistance of the copolymers, and the elastic-strength properties, due to the increased chain rigidity. It determined the influence of technological modes of 3-D printing by layering molten polymer filaments on the physico-mechanical properties of polyether sulfones.

Retarded Cross-linking in ZnO-low-density Polyethylene Nanocomposites

2002 ◽  
Vol 17 (5) ◽  
pp. 940-943 ◽  
Author(s):  
J.I. Hong ◽  
K. S. Cho ◽  
C. I. Chung ◽  
L. S. Schadler ◽  
R. W. Siegel
Keyword(s):  
Thermal Stability ◽  
Thermal Properties ◽  
Thermal Degradation ◽  
Surface Properties ◽  
Zno Nanoparticles ◽  
Low Density Polyethylene ◽  
Cross Linking ◽  
Low Density ◽  
Zno Particles ◽  
Thermal Stability Of

ZnO nanoparticles were mixed with branched low-density polyethylene and were found to increase the resistance of the polymer to thermal degradation without changing other thermal properties. Submicron-size ZnO particles were mixed with low-density polyethylene for comparison, and it was found that the increased thermal stability of the nanocomposite was due to the surface properties of nanoparticles smaller than approximately 100 nm in diameter.

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