| 摘要 |
Polymers are continuously produced from ethylenically-unsaturated compounds, which are solid or liquid at 18-22 DEG C., by polymerization in a tubular reactor with forced feed at 10-1000 atmospheres and 100-300 DEG C., the molten polymer being subjected to shear forces. The shearing reduces the molecular weight of the polymer and may be carried out in an extruder, which may also form the reactor. The monomers may be styrene together with acrylonitrile and/or methyl methacrylate, or acrylamide. Polymerization may be in bulk using a free radical forming catalyst, e.g. azo-diisobutyronitrile, benzoyl peroxide or cumene hydroperoxide. Monomers or oligomers may be removed from the polymer in a degassing zone. The polymer may be formed into a strand, which may be granulated, or into a transparent sheet. Apparatus for carrying out the above process is described and illustrated by Figs. 1 and 2 (not shown).
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