插层条件对蒙脱土／偶氮二甲酰胺复合发泡剂的影响及应用

Effect of Intercalation Conditions on Montmorillonite/Azodicarbonamide Composite Foaming Agent and Its Applications

以超临界二氧化碳(scCO_2)为介质,将偶氮二甲酰胺(AC)发泡剂插层到蒙脱土(MMT)中,制备MMT/AC复合发泡剂;通过红外光谱、热失重、X射线衍射和扫描电子显微镜分析方法对复合发泡剂进行表征;探究了插层条件对复合发泡剂中AC插层效果及MMT形貌的影响,以得到最优插层条件;结果表明,40℃、20 MPa、100 r/min为最优插层条件,且在此条件下最有利于改善MMT的团状结构;MMT/AC复合发泡剂在聚丙烯中注塑发泡无需添加发泡助剂,当注塑温度为190℃时,泡孔尺寸较均匀,泡孔孔径约为250μm。

A composite foaming agent composed of montmorillonite （MMT） and azodicarbonamide （AC） was prepared by intercalating AC into MMT in supercritical CO2 medium, and then was characterized by Fourier-transform infrared spectroscopy, thermogravimetric analysis, powder X- ray diffraction and scanning electron microscopy. An optimum condition of 40℃, 20 MPa and 100 r/min for the supercritical intercalation was obtained on the basis ＂of the investigation of intercalating effect and morphology of the AC-intercalated MMT. The agglomeration structure of MMT was improved at this condition. The MMT/AC composite foaming agent could be directly used for the foaming process of polypropylene （PP） without any other additives. PP foams achieved a cell size of about 25μm and a uniform size distribution at an injection molding temperature of 190℃.