Transition Behavior and Phase Structure of Cellulose/Poly(iV-vinylpyrrolidone) Composites Prepared hy a Solution Coagulation/Bulk Polymerization Method

Abstract

Cellulose/poly(N-vinylpyrrolidone) (CELL/PVP) composites were synthesized via photo-initiated polymerization in a gel state of cellulose swollen in N-vinylpyrrolidone (VP) monomer containing a small amount of cross-linking agent, ethylene glycol dimethacrylate. The cellulose gels were formed from solutions in dimethylacetamide-lithium chloride by coagulation with ethanol, followed by exchange of the coagulant into VP monomer as reactive impregnant. The thermal transition behavior and phase construction of the CELL/PVP composites obtained over a wide composition range were characterized mainly through DSC and dynamic mechanical analysis. For compositions rich in PVP (CELL< 15 wt%), it was resonably assumed from swellig and viscoelastic data that an original structure of cellulose gels was successfully fixed into the polymerized bulks, resulting in the formation of an interpenetrating network (IPN) type organization. However, these PVP-rich samples gave a Tt value lower than that of PVP alone. Some potential effects due to a specific interaction between cellulose hydroxyls and VP carbonyls in the process of photopolymerization are discussed. © 1994, The Society of Polymer Science, Japan. All rights reserved.