SYNTHESIS AND CHARACTERIZATION OF STARCH-BASED POLYURETHANE FOAMS

Starch-based polyurethane foams were synthesized by reacting a mixture of starch and polycaprolactone triol with an aliphatic diisocyanate, in the presence of water as blowing agent. Some foams were also prepar ed by adding a certain amount of polyethyleneglycol. The reaction kine tics is affected by the presence of starch due to the higher viscosity related to the presence of the high molecular weight polysaccharide. Starch-based polyurethanes show higher glass transition temperatures a nd lower thermal stability. Cellular materials with different mechanic al properties can be obtained by varying the amount of starch and by c ontrolling the relative amount of polycaprolactone triol and polyethyl eneglycol in the composition. (C) 1998 John Wiley & Sons, Inc.