Abstract: A method for purifying N-vinyl-2-pyrrolidone (NVP) is disclosed. The method comprises crystallizing NVP in the presence of added water to produce purified NVP crystals and a mother liquor, and then isolating the purified crystals. In a preferred method, 0.5 to 4 wt. % of water based on the amount of NVP to be purified is added, and the NVP crystals are washed with additional pure NVP, preferably NVP crystal melt, to give crystals having a purity greater than 99.99%. The method provides a fast, effective way to generate and isolate pure NVP in a single-stage crystallization.

Abstract: A process for purifying grafted polyolefins by extraction is disclosed. The purified grafted polyolefins have improved color and adhesion properties. The extraction is performed with an azeotropic solvent that is strong enough to extract impurities but does not cause sticking of the grafted polyolefin. The azeotropic solvent can be easily recycled.