| 摘要 |
An advanced method comprises (i) homogeneously mixing (a) polymer 100 wt.% (av. mol. wt. 100,000-350,000 g/mol, obtd. from polymg. alkenyl aromatic monomer 99-70 wt.% and olefinically unsatd. acid 1-30 wt.% selected from a gp. of acrylic acid, methacrylic acid, itaconic acid or these mixt.) and (b) foaming agent i.e. carbonate, carbonate hydrate or bicarbonate of Na, Mg, Zn, NH4+ and these mixt. 0.5-20 wt.%, (ii) thermoplasticizing under pressure enough to prevent from foaming and at high temp. enough to dissociate and (iii) passing into lower pressure zone to prepare foams (d.=8-128 kg/m3 (0.5-8 lb/ft3), cell size=0.1-5 mm).
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