| 摘要 |
industrial organic synthesis. SUBSTANCE: invention relates to polycarbonate production technology, in particular to isolation of polycarbonate from solution in chloroalkane formed in the process of phosgenation of diphenylolpropane disodium salt in heterogeneous methylene chloride-water system in presence of catalyst. Polycarbonate is isolated from solution in methylene dichloride, dichloroethane, or chloroform by adding acetic acid to precipitate polycarbonate. Solution of polycarbonate in chloroalkane is mixed with acetic acid at weight ratio of polycarbonate, chloroalkane, and acetic acid 1:(8.93- 9.36)L(4.02-6.03), respectively. Chloroalkane is distilled off before solid polycarbonate-acetic acid-chloroalkane complex is formed, which is further separated. Polycarbonate is recovered in the form of spherical granules having high apparent density (at least 0.35-0.40 g/cu.cm) and thermal stability by treating solid complex with hot water at temperature above boiling temperature of chloroalkane, while simultaneously distilling off chloroalkane. EFFECT: increased apparent density and thermal stability of polycarbonate, and simplified its isolation technology. 8 ex
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