| 摘要 |
FIELD: polymer production. SUBSTANCE: low-density porous cross-linked polymer materials are produced via polymerization of water-in-oil emulsion with high content of internal phase. Emulsion contains mixture of reactive monomers with at least one vinyl monomer, at least 90 wt % (based on emulsion) of water as internal phase, 2 to 4 wt % (based on monomers) of surfactant, and polymerization catalyst. Emulsion is heated to polymerize and cross-link monomers. The latter contain from 2 to 55% bifunctional unsaturated monomer capable of forming cross links. Above-mentioned surfactant contains (i) sorbitan monoester with at least 6 carbon atoms in fatty acid moiety and (ii) at least one other sorbitan ester with at least one fatty acid moiety other than in (i). More specifically, fatty acid moiety of component (i) contains 6 to 30 carbon atoms, so (i) can be, for instance, $$$, $$$, or $$$-fatty acid ester of sorbitan, whereas (ii) includes sorbitan ester with at least one fatty acid moiety other than that with at least 6 carbon atoms. In particular, component (i) is selected from following esters: sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, and sorbitan monooleate; and component (ii) is sorbitan monopalmitate. Besides components (i) and (ii), surfactant contains component (iii): at least one sorbitan ester other than esters (i) and (ii). Content of component (i) in surfactant ranges from 5 to 95 wt %. Emulsion is heated until at least 85% of monomers is converted. According to invention, vinyl monomer includes at least one monoalkenyl aromatic hydrocarbon, or acrylic or methacrylic acid ester. Bifunctional unsaturated monomer capable of forming cross links between molecules is at least one compound from the following group: divinylbenzene, diethylene glycol dimethacrylate, 3-butylene methacrylate, and allylmethacrylate. Emulsion also contains electrolyte. Content of catalyst ranges from 0.005 to 15 wt. % relative to monomers. Emulsion is hardened at temperature from 25 to 90 C. EFFECT: expande
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