| 摘要 |
Unsaturated polyesters are made by polycondensing (a) an a ,b -unsaturated dicarboxylic or anhydride (e.g. maleic, fumaric, itaconic, citraconic or mesuconic acids) and (h) 2,2-dimethyl - 4 - methyl - hexane - 1,6 - diol and/or 3,3 - dimethyl - 5 - methyl - hexane - 1,6 - diol. Part of the unsaturated dicarboxylic component may be replaced by a saturated dicarboxylic acid or an anhydride or dimethyl ester thereof (e.g. succinic, sebacic, adipic, phthalic, isophthalic or terephthalic acids). The polyesters may be stabilized with hydroquinone or p-tertiary butylcatechol and latter dissolved in polymerizable monomers (e.g. styrene, vinyl toluene, divinyl benzene, dialkyl isophthalate, diallyl terephthalate, triallyl cyanurate, methyl methacrylate butyl methacrylate acrylamide, a mixture of vinyl toluene and triallyl cyanurate, or a mixture of styrene and diallyl terephthalate). Hardening may then be effected by addition of organic peroxides, organic hydroperoxides or azo compounds and, possibly, a heavy metal compound or a tertiary amine. Fillers (e.g. a mixture of silicon carbide, powdered quartz and asbestine) may be added. The polymerizable compositions may be used to impregnate glass fibre mats. |
