Polyvinylchloride cross-linking

In the United States high molecular weight polyethylene is used, and in the United Kingdom, cross-linked polyethylene with polyvinylchloride is used. 

Acrylic and allyfic compounds These have been reported to enhance cross-linking in polyvinylchloride [84], PE [85], PP [86], polyisobutylene, and EP copolymers [87], butadiene-styrene copolymers, and NR [88] each compounded with 50 phr of carbon black. 

When tested in other polymers, maleimides did not affect the rate of cross-linking in polydimethylsiloxane, polyisobutylene, and polyvinylchloride. In polyethylene, the addition of 5 wt.% of m-phenylene dimaleimide increased the G(X) from 1.8 to 7.2. In the polyvinylacetate the effect was even more pronounced the dose for gelation was reduced by about a factor of 50. Contrary to the cross-link enhancing effect found for m-phenylene dimaleimide, cross-linking was retarded in polyvinyl acetate by the addition of monomaleimides. When analyzing the mechanism of the reaction it was concluded that monomaleimides are not expected to affect cross-linking in saturated polymers. ... 

The largest volume of polymeric materials used for wire and cable insulation is thermoplastics, namely polyethylene (PE) and polyvinylchloride (PVC),4 and, to a lesser degree, elastomeric compounds. The main reason for the prevalence of the PE and PVC in wire and cable insulation is their easy processing and relatively low cost. However, their main disadvantage is that their physical properties, such as plastic flow at elevated temperatures, environmental stress cracking, poor solvent resistance and low softening temperatures,3 cannot always meet demands imposed on them by modern applications. Cross-linking of these materials improves their... 

Anthony, G. M. Kinetic and chemical studies of polymer cross-linking using thermal gravimetry and hyphenated methods. Degradation of polyvinylchloride. Polymer Degradation and Stability 1999 64 353. 

The rate of production of wire and cable insulated with radiation cross-linked polyvinylchloride is increasing steadily. Such insulation has better resistance to heat and chemical attack and increased cut-through resistance, and is more compact. The products are used in the automobile industry, telecommunications, the aerospace industry, and in home electrical appliances. 

Other areas of use are in the polyvinylchloride (PVC) industry as a stabilizer, in which the organotin acts as a Lewis acid to scavenge the HCl released during extrustion. Organotin species are also used as catalysts for polyurethane coatings. Si cross-linking. 

A number of manufactured products comprising thermoplastics (polyethylene, polyvinylchloride, polyamides,. ..) or elastomers (natural rubber, nitrile rubber, ethylene propylene rubber, silicones) are processed by cross-linking to improve their performances in insulated electric wires and cables, multilayered films for cooking pouches, shape memory tubes, pressure resistant water pipes, expandable foams, automotive parts exposed to motor... 

Yoshioka H, Mikami M, Mori Y, Tsuchida E (1993) Preparation of thermoresponsive surfaces using polyvinylchloride-graft-poly(A-isopropylacrylamide). Polym Adv Technol 4 519-521 Yu H, Grainger DW (1993) Thermosensitive swelling behavior in cross.linked N-isopropylacry-lamide networks-cationic, anionic, and ampholytic hydrogels. J Appl Polym Sci 49 1553-1563... 

Polymers can be divided into two main classes on the basis of their reactivity to NO [1]. Saturated polymers such as polyethylene (PE) and polypropylene (PP) belong to the first group, but Nylon 66 does not. The second group covers elastomers. Butyl rubber (BR) undergoes scissions of the main chain, and polybutadiene is extensively cross-linked under the action of NO. These elastomers have approximately the same reactivity to NO as to ozone. All films exposed to NO become yellow, and their infrared (IR) spectra show that nitro groups enter into macromolecules. In polyvinylchloride in the presence of NO, a decrease in the amount of chlorine, along with the appearance of nitro and nitrite groups, are observed from IR spectra. 

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