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Pureland

木虫之王 (知名作家)

[资源] 应用高分子前沿1——泡沫最新进展（英文版）

Introduction
Generally speaking, foams deliver low density and insulating properties, two features more and more appreciated in sectors as varied as aeronautics, automotive, transportation, packaging, building and others. Surprisingly, light foams are also commonly used as core materials for structural composites leading to high performance/weight ratios reducing fuel costs of automotive, transportation and aircraft applications. Insulation properties applied to building, transportation, aerospace, cryogenic sectors also generate high energy and cost savings.
Manufacturers continue to look for new potential weight and cost savings through innovative high performing materials taking advantage of collateral properties of polymer foams such as high temperature behavior, cryogenic temperature applications, solvent resistance, ageing resistance etc. As for the other materials, use of renewable resources replacing petroleum is more and more required to satisfy environment trends and to obviate possible scarcity of petroleum.
Obviously, ideal cases are biodegradable foams made out of renewable sources that can return to ground as carbon source after use. Starch-based foams, expanded aliphatic polyesters or PLA are proposed. Polyurethane foams partially made of natural polyols are of interest allowing to obtain properties of the same order as fossil polyurethane for a bio-carbon content of 20 up to 90%.
Foam innovation includes also new processing methods. So, a versatile Microcellular Foam technology, the Mucell process is developing that enables the production of high quality plastic parts with significantly higher performance/weight ratios, enhanced dimensional stability, and reduced cycle time. The thermal insulation performance of a polyurethane rigid foam depending chiefly on the size of the foam pores, researchers and producers study new processing methods leading to smaller and smaller cell diameters resulting in Polyurethane Nanofoams for the last evolution.
Hi-Tech advanced foams are another trend using engineering plastics, and advanced polymers including SAN, PET, PA, PVDF, polyimide, PEI, Pebax among others, combining the advantages (and also drawbacks) of foams and those of the used polymer. This paper deals with some innovative solutions but many other technologies are developing or emerging such as foamed composites including WPC, melamine foams, syntactic components etc.

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