| 摘要 |
A foamable body is made from a polymerizable material comprising (a) monomeric mono- or a dichlorostyrene, a dibromostyrene or methyl methacrylate, the halostyrenes being nuclearly substituted, (b) mixtures of said monomers, (c) mixtures of one or more of said monomers with up to 30% by weight of styrene based on the weight of polymerizable material or (d) the polymerizable material (a), (b) or (c) containing from 0.035 to 1 weight per cent of a difunctional copolymerizable monomer, and a blowing agent which process comprises polymerizing the polymerizable material at a temperature from 0-80 DEG C. under atmospheric pressure while the polymerizable material and the expanding agent are restrained in a mold having the form of the desired body. Typical blowing agents are trichlorofluoromethane, dichlorotetrafluoroethane, trifluorotrichloroethane, pentanes, hexanes and other hydrocarbons, or solids such as a ,a 1 azobis isobutyronitrile, p,p1-oxybis-benzene sulphonyl hydrazide and sodium carbonate or a trace amount of p,p1-oxybis-benzene sulphonyl hydrazide with a volatile organic liquid polymerization may be catalysed by such catalysts as di-isopropyl perocxy dicarbonate, dimethyl aniline activated benzoyl peroxide and cobalt activated methyl ethyl ketone-peroxide or by using high energy ionizing radiation. Fillers, dyes and pigments can be incorporated in the reaction mixture. Preformed polymer may also be added to the monomer. In Example 5, the polymerizable mixture consists of orthochlorostyrene, a butadiene - acrylonitrile copolymer rubber, acrylonitrile, trichlorofluoromethane, oxybis-(benzene sulphonyl hydrazide), 1 : 1-divinyl benzene-ethylvinyl benzene mixture and di-isopropylperoxydicarbonate. The foamable bodies are expanded by heating in an air oven. |
