| 摘要 |
<p>Vinyl monomer prepolymer prod. by block polymerisation of methacrylates, opt. mixed with acrylates or styrene, takes place at 90-160 degrees C under an opt. O2-enriched air atmos. or under an inert gas. An initiating system is used, consisting by wt. wrt 100 pts. wt. vinyl monomer, of (1) 0.05-0.3 parts peresters having formula RCOOOCMe3 (where R is aryl, alkyl, isoalkyl, Me-, Ph- or benzyl carbitol) and (2) are of following components: (a) 0.2-3 pts. divalent S present as S-contg. acids or their esters, (b) 0.3-2.5 parts mixt. of 4-20C mercaptans and S-contg. acids, where wt. ratio mercaptans: S-contg. acids is 0.1-0.5:0.2-2, or (c) 0.3-2.5 parts mixt. of 4-20C mercaptans and 14-22C fatty acids, where wT. ratio mercaptans: fatty acids is 0.1-0.5:0.2-2. The prepolymers can be used for impregnating glass fibres, wood in prodn. of constructional materials, for prodn. of organic flat glass by block polymerisation, and for prepn. of casting- and extrusion granulates. Initiator system for Me methacrylte preopolymerisation in air contained, by wt. 0.1% tert. bu perbenzoate, 0.3% lauryl mercaptan and 1% stearic acid.</p> |
