SYNTHESIS AND APPLICATIONS OF PHOTOCROSSLINKABLE POLY(SILOXANES)

This survey concerns the synthesis and curing of poly(siloxanes) by UV radiation and electron beams. Three main kinds of products are descri bed; firstly, those formed by an applied radical mechanism and constit uting acrylated poly(siloxanes) linked by either Si - OC bonds or Si - C bonds, or by urethane acrylated poly(siloxanes) or by the thiol-ene s system; secondly, those using a cationic mechanism and listed the ep oxy grafted poly(siloxanes); the vinyl; and the styrenic corresponding compounds; and thirdly one which is a special type of poly(siloxane) cured by a noble metal or SiH-Si vinyl. In each case, the mechanism, p hotosensitizers, additives, reactive diluents and apparatus for curing formulations are given. Finally some applications and properties of t hese products, mainly in the field of coating such as release papers a re described. An attempt has been made to relate the structure of thes e kinds of poly(dimethylsiloxanes) (PDMS) to their properties.