| 摘要 |
<p>A biodegradable packing, filling and cushioning material, opt. as a loose filler, with low density, based on foamed polymers, comprises a basic compsn. expanded by action of its own moisture from a re-solidified gel melt with a large number of small hollow spaces and 5-20 wt.% water content, which has been plasticised under raised temp. and pressure, and (a) contg. starch or plant material contg. starch, pref. unmodified, partic. parts of plants, contg. at least 50% (at least 60%) of starch, and (b) 1-40% (5-25%) of a thermoplastic elastomer. Pref. (a) the melt gel is based on a native starch-contg. cereal, grain, root, tuber and/or stem, esp. a legume, maize, rice potatoes and/or cassava. (b) The elastomer is based on styrene and a polyene or diene, esp. a linear copolymer of styrene and/or methylstyrene and butadiene and/or isoprene. The compsn. contains 0.5-20 (0.8-10) wt.% of glycol, glycerol, (poly)ethylene glycol, (poly)-propylene glycol and/or a low-mol. polyol, as moisture-retaining agent, 0.1-5% of a natural and/or mineral and/or synthetic dye, and/or 0.02-0.5% of a biocide, esp. a rodenticide, and as expansion aid, a water-miscible solvent with b.pt. 70-130 deg.C. and/or a salt which splits off a gas.</p> |
