【作者】 强薇； 胡冬冬； 刘涛； 赵玲；

【Author】 Qiang Wei;Hu Dong-dong;Liu Tao;Zhao Ling;State Key Laboratory of Chemical Engineering,East China University of Science and Technology;

【机构】 化学工程联合国家重点实验室华东理工大学；

【摘要】 气体在聚合物中的溶解扩散行为对于聚合物发泡过程及泡孔结构控制影响显著。CO₂在聚合物中溶解度较低、泡孔生长过程中扩散较快,导致超临界CO₂发泡过程难以控制。本文研究了亲CO₂添加剂的分子量（M_w）对超临界CO₂在聚苯乙烯（PS）中扩散和解析的影响,并且利用超临界CO₂间歇发泡验证了亲CO₂添加剂对PS发泡结果的影响。结果表明,低分子量的亲CO₂添加剂可以增加CO₂在PS的扩散系数从而缩短发泡饱和时间。低分子量的亲CO₂添加剂可以减缓CO₂的解析速度从而使PS中保留的CO₂含量较高。因此,在PS基体中加入低分子量的亲CO₂添加剂进行超临界CO₂发泡可以得到较小的泡孔和较高的发泡密度的泡孔结构。更多还原

【Abstract】 The solubility and diffusivity of gas in polymer matrix play crucial roles in controlling the CO₂ foaming process and foam structure.The low solubility and the high diffusion coefficient（D）of CO₂ in polymers lead to the difficulty of controlling the CO₂ foaming.In this work,the effect of molecular weight（M_w）of CO₂-philic additives on the diffusion of supercritical CO₂ into and out of polystyrene（PS）was investigated via experiments.The batch foaming process was carried out to testify the effect of CO₂-philic additives on PS foaming results.The saturation time of foams was shortened as low M_w CO₂-philic additives increased the D of CO₂ in PS.The slow CO₂ desorption rate in PS with low M_w CO₂-philic additives enabled higher amount of CO₂ retained in the PS.Hence,PS with low M_w CO₂-philic additives foams presented smaller cell size and larger cell density.更多还原