Humid- and age-tolerant starch-based sponge for loose-fill packaging.

摘要

Loose-fill packaging sponges were extruded from mixtures of 54-62% hydroxypropylated (HP {dollar}approx{dollar} 5%) amylomaize V (50% amylose) and wheal starches, 17-24% of synthetic polymer, {dollar}sim{dollar}13% water, 7% of blowing agent, and 0.5% of nucleating agent. One product, made from 28% HP wheat starch, 28% HP amylomaize V starch, 12% ethylene vinyl alcohol copolymer (EVOH), 8% polystyrene (PS) and 3% polystyrene maleic anhydride copolymer (PSMA), plus the other raw materials, had compressibility and resilience that matched expanded polystyrene (EPS), although its bulk density was 4 times higher. The starchy sponge showed only 16% shrinkage in volume at 90% relative humidity and was 2% soluble in excess water, both at 25{dollar}spcirc{dollar}C. After aging 18 months near 25{dollar}spcirc{dollar}C, the HP starchy sponge gave a trace of fines in a simulated shipping test compared to 20% for a biodegradable starch-based loose-fill of commerce.