Silane cross-linking

Durand, M. L., and Dietrich, A. M. (2007). Contributions of silane cross-linked PEX pipe to chemical/solvent odours in drinking water. Water Sci. Technol. 55(5), 153-160. 

Plasma-polymerized materials differ significantly from those polymerized by conventional methods in their surface properties, and surface tension values do not correspond. This difference may be due to the highly cross-linked nature of plasma polymers or to the incorporation of other entities from the carrier gas. These effects are more important than the intrinsic differences in backbone fiexibility. Wrobel (88) presents ATR-IR (attenuated total reflection infrared) spectroscopic data indicating that silazanes and silanes cross-link more readily than do siloxanes under plasma conditions. Wrobel and his co-workers (89) have also used contact angles to study the thermal decomposition of plasma-polymerized organosilicon polymers. 

Many commercial polymer matrices can be processed into single-component, moisture-curable systems by means of silane cross-linking (Scheme 1) [3]. 

A silane—the method is called cross-linking via silane or moisture-based vinyl silane cross-linking. The resulting PE is also called PEX-C in the European standards. 

Cross-linking polyethylene enhances its heat resistance (in terms of resistance to melt flow) since the network persists even about the crystalline melting point of the uncross-linked material. Cross-Knked polyethylene thus finds application in the cable industry as a dielectric and as a sheathing material. Three main approaches used for cross-linking polyethylene are (1) radiation cross-linking, (2) peroxide cross-linking, and (3) vinyl silane cross-linking. 

In the vinyl silane cross-linking process Sioplas process) developed by Dow, an easily hydrolysable trialkoxy vinyl silane, CH2=CHSi(OR)3, is grafted onto the polyethylene chain, the site activation having been achieved with the aid of a small amount of peroxide. The material is then extruded onto the wire. When exposed to hot water or low-pressure steam, the alkoxy groups hydrolyze and then condense to form a siloxane cross-link ... 

The cross-linking reaction is facilitated by the use of a cross-linking catalyst, which is typically an organotin compound. There are several variations of the silane cross-linking process. In one process, compounding, grafting, and extrusion onto wire are carried out in the same extruder. 

BP Chemicals have introduced a new technology for silane cross-linking in low-voltage cable insulations to produce more uniform cross-linking and greater shelf-life. The new silane-linked polyethylene compounds can be run on conventional extrusion equipment. The company has also produced a strippable double layer cable shield in cross-linkable polyethylene for medium voltage cables. 

Goto T. Material recycling of silane cross-linked polyethylene insulated cable using supercritical alcohol. Electrical Insulation News in Asia [trade journal— Institute of Electrical Engineers of Japan] October 2006. 

Silane cross-linking Multifunctional silanes Silieone robbers, PE... 

Atkinson J.R., and R.Z. Cicek. 1983. Silane cross-linked polyethylene for prosthetic applications. Part I. Certain physical and mechanical properties related to the nature of the material. Biomaterials 4 267-275. 

Thermal degradation kinetics of LLDPE and TGA was employed to study the degradation Silane cross-linked LLDPE was found to be Zong et al. 2005... 

Silane cross-linked mechanisms thermally more stable ... 

Silane cross-linking - specifically the one-shot system - employs a three-component mix (of peroxide, silane, and tin catalyst, either in the form of liquid of dry masterbatch) that is added separately to the compound during extrusion. The reaction is in two stages, the temperature of extrusion being used to decompose the peroxide in order to react the silane molecule onto the polymer backbone. 

Wang S, Zhao C, Ma W et al (2013) Silane-cross-linked polybenzimidazole with improved conductivity for high temperature proton exchange membrane fuel cells. J Mater Chem A 1 621-629... 

Durand, D., Dietrich, A. (2007). Contributions of Silane Cross-Linked PEX Pip>e to Chemical/Solvent Odors in Drinking Water, Water Science and Technology 55(5), pp. 153-160, ISSN 0273-1223. 

Silane adhesion promoters have been studied for the corrosion protechon of metal surfaces. The use of a silane in combinahon with a silane cross-linking addi-hve (Table 25.6) and with sulfur silanes (Table 25.14) have yielded very promising coating systems to replace the toxic chromates in steel [22]. Similar corrosion protection was realized on cold-rolled steel, iron, aluminum, and aluminum alloy surfaces by treatment with the same cross-linker system but in combination with aminosilanes in the admixture [23]. 

There are three main cross-linking chemical methods azo, peroxide, and silane cross-linking. There is... 

With silane cross-linking processes, the cross-linking reactions occur while the polymer is in the solid state. As such, the polyethylene material exists with both crystalline and amorphous regions being present. There will be differences in the degree of... 

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