聚丙烯微孔发泡材料的研究进展

Progress of preparation of polypropylene microcellular foam

聚丙烯(PP)发泡材料具有优异的力学性能和热性能,PP属于结晶型聚合物,在温度低于熔点时,存在结晶区,相态为固态,难以发泡;而温度达到熔点时,熔体强度急剧下降,导致泡孔聚并和破裂。目前,关于超临界二氧化碳制备PP微孔发泡材料的研究主要聚焦于改善PP的发泡行为,通过添加纳米颗粒或聚合物来调控PP的结晶方式,采用直接合成、共混改性和辐照交联等手段提高PP熔体强度,以及改进发泡方法来获得PP微孔发泡材料。

Polypropylene（PP） foam has excellent mechanical and thermal properties. However, it is very difficult to foam for PP. PP is as a crystalline polymer when the foaming temperature is lower than PP melting temperature, PP is solid, so that it can not be expanded; when the foaming temperature is above the melting temperature, the melting strength of PP decreases dramatically and the cells will coalesce and rupture. Therefore, the current researches on the preparation of PP microcllular foam via supercritical carbon dioxide mainly focus on how to improve its foaming behavior. The methods to obtain the PP microcellular foam include： adding nanoparticle and/or polymer to adjust crystallization behavior, enhancing the melting strength of PP through direct synthesis, polymer blending, and/or radiation crosslinking, and modifying the foaming process.