聚烯烃弹性体发泡材料的研究进展OA

Polyolefin elastomer(POE)is a class of elastomeric material resulting from the copolymerization of ethylene/propylene and a-olefin,which is known for high elasticity,good strength,excellent low-temperature resistance,and favorable processability.It has therefore been widely used in automotive parts,protective packaging,footwear,and sports products.In the automotive field,especially in the field of new energy vehicles,lightweighting of automobiles can effectively reduce their energy consumption,and thus it is important to use lightweight materials.In the field of sports shoes,lightweight shoes can effectively reduce the physical consumption of athletes and reduce the risk of sports damage.As a result,enough attention has been paid to the study of material lightweighting.To achieve this goal,chemical foaming and physical foaming of POEs have become common and effective means.Against this backdrop,this paper presents a comprehensive review of recent advances in POE foam materials.The review is organized around two main technical routes:chemical foaming and physical foaming,which differ fundamentally in their foaming mechanisms.For chemical foaming,there is a chemical reaction in the foaming process.In contrast,physical foaming has no chemical reaction during foaming,thereby being more environmentally friendly.For each route,the effects of various foaming systems on cell morphology,expansion ratio,and overall material performance are systematically discussed.For the chemical foaming of POE,the matching of the amounts of foaming agent and crosslinking agent with the foaming temperature is very important,which determines the cell size and mechanical properties of the foam material.For the physical foaming of POE,the foaming process parameters,such as temperature,pressure,and crosslinking or branching structure of the polymer,can influence the cell size and cell density of the foam material.In addition,several critical challenges currently facing the field are addressed,including the dynamic balance between cell growth and melt strength,the marked decline in mechanical properties at high expansion ratios,and the difficulty in ensuring uniform cell structure in continuous industrial production.To tackle these issues,several promising directions for future research are proposed.The dynamic mechanism of cell nucleation,growth,and stabilization needs to be deeply revealed.Overall,this work is intended to provide a systematic theoretical basis and technical guidance for the structural design,process optimization,and expanded lightweighting applications of POE foams in the automotive and footwear sectors.This is of great significance for the industrialization of POE foam materials.