DMDBX对聚乙烯结晶结构及性能的影响

Effect of DMDBX on crystal structures and crystallization behaviors of polyethylene

以木糖醇和3,4-二甲基苯甲醛为原料,利用缩醛反应机理,合成二(3,4-二甲基二苄叉)木糖醇(DMDBX),并对化学结构进行了表征.使用溶液沉淀法制备多种PE粉末样品,DMDBX添加量分别为PE质量分数的0.1%、0.3%、0.5%、0.7%和0.9%.采用X衍射仪、红外光谱仪、偏光显微镜和差示扫描量热仪研究样品结构与性能的关系.结果表明,DMDBX能够促进PE异相成核,减小PE球晶尺寸,提高PE结晶度,可以作为PE结晶成核剂.根据Avrami模型及Kissinger方程计算了PE结晶动力学数据.该成核剂能提高PE结晶速率,降低活化能,在DMDBX添加量为PE质量分数的0.3%时,成核结晶效果最明显.

1,3-2,4-di-(3,4-dimethyl-benzylidene)xylitol(DMDBX)was synthesized by xylitol and 3,4-dimethyl-benzaldehyde by acetalization.A series of PE samples was prepare using solution-precipitation method with DMDBX mass fractions of 0.1%,0.3%,0.5%,0.7%,and 0.9%.The crystal structures and crystallization behaviors of these PE samples were investigated by X-ray diffractometer,FT-IR,polarized light microscope,and differential scanning calorimeter.The results show that DMDBX can promote the heterogeneous nucleation,kee...