从二氧化碳制备生物可降解塑料——机会与挑战

Opportunity and challenge in carbon dixoide based plastics

从CO2制备塑料成为目前化学化工领域备受关注的研发方向,其原因一方面在于CO2作为化工资源的规模化利用,另一方面则是所得到的塑料具有生物可降解性能,为解决长期制约生物降解塑料发展的性价比难题提供了难得的机遇。本报告介绍了二氧化碳基塑料研发方面的最新进展,指出生物降解只是二氧化碳基塑料的诸多性能之一,但不是实现其规模化应用的决定因素。不断提高其性价比,使其与普通塑料相比有竞争力,是二氧化碳基塑料面临的最大挑战。二氧化碳基塑料的性价比取决于其高效合成和性能改善的程度,一方面其高效制备受制于催化剂活性、聚合工艺、聚合后处理技术等因素,其中提高催化活性是降低其成本的核心。另一方面,二氧化碳基塑料的玻璃化温度较低(35℃左右)、且为无定型结构,存在尺寸稳定性差(40℃以上)和低温脆性(18℃以下)的问题,能否在保持生物降解性能的前提下,解决低成本的高温增强和低温增韧难题,是二氧化碳基塑料改性的关键。

Fixation of carbon dioxide into plastics is becoming a hot area, not only due to the utilization of carbon dioxide as raw material for chemical industry, but also the biodegradability of the obtained polymer. Though this plastics shows great opportunity as a solution for future biodegradable plastics industry, it faces harsh challenge of dramatically raising the performance/price value. The report will introduce the recent progress in R&D of carbon dioxide based plas-tics, an alternative high molecular weight copolymer of carbon dixoide and propylene oxide, focusing on how to raise per-formance/price value of this biodegradable plastics. In one side, developing catalyst of high efficient and good product se-lectivity is of great importance for reducing the cost of this plastics as well as controlling the metal ion content in the plas-tics. In another consideration, since this plastics shows low glass transition temperature(35℃) and amorpous structure, it is brittle below 18℃ while rapidly loses dimension stability above 40℃ , therefore, toughening at high temperature and plasticizing at low temperature are badly needed. It should be noted that the cost for modification should be concerned in addition to biodegradability, otherwise it is too far to compete with polyolefins in the market.