Vinyl caprolactam → Vcl VP

Participants

Reaction Steps

630 g. of isopropanol was charged into a 1-liter resin kettle fitted with a propeller agitator, a reflux condenser, a nitrogen inlet tube, and a thermowatch. The reactor was heated to 82° C. and maintained at this temperature throughout the experiment. A monomer premix was prepared by mixing 52.50 g of vinyl caprolactam, 17.50 g of vinyl pyrrolidone and 1.40 g of t-amyl peroxy-2-ethylhexanoate initiator (Lupersol 575, 95% liquid; Elf Atochem) in a 250-ml beaker. The monomer pre-mix was pumped into the kettle over a period of 2 hours. The reaction then was held at 82° C. for 1 hour. Thereafter 0.50 g of t-amyl peroxy-2-ethylhexanoate was added and the reaction was held 82° C. for 1 hour. The step was repeated twice. At the end of the reaction, a 10% light-brown, viscous poly(vinyl caprolactam) in isopropanol was obtained after cooling to room temperature. Residual vinyl caprolactam was 0.21% by GC analysis. The polymer had a relative viscosity of 1.084 (1% in isopropanol), a GPC molecular weight of 2,640 (polyethylene glycol standard). Dry VCL/VP (75/25) copolymer powder was obtained by vacuum stripping.

Provenance & Evidence