| 摘要 |
<p>1310442 Polypyrrolidone RADIATION RESEARCH CORP 6 April 1970 [7 April 1969] 16108/70 Heading C3R A process for producing solid polymers of 2- pyrrolidone comprises heating 2-pyrrolidone with an alkali metal bicarbonate polymerization catalyst at 120‹ to 200‹ C. for 30 to 180 minutes, cooling the heated mixture to a polymerization temperature not exceeding 100‹ C., and polymerizing it at this temperature after removal of water formed from reaction of the monomer and bicarbonate and any other water. Use of a co-catalyst is stated not to be necessary and it is preferred that the bicarbonate is the sole catalyst to ensure a narrow molecular weight distribution. It is also possible to use CO 2 as a co-catalyst; it may be bubbled through the monomer/bicarbonate mixture before, during or after the heat activation step. Polymerization may be effected in bulk or in dispersion and the monomer is desirably purified; suitable purication techniques are described. In examples K, Na, Rb and Cs bicarbonates are used while comparative examples illustrate the use of K pyrrolidonate and acetyl pyrrolidone or CO 2 as catalyst and also KHCO 3 with heat activation at only 114‹ C. for 15 minutes. The products of the invention are white and may be melt extruded, e.g. as fibres, films or rods.</p> |
