木糖醇醛类化合物对聚乙烯结晶结构及性能的影响  

Effects of Xylitol-aldehyde Compounds on Crystalline Structures and Crystallization Behaviors of Polyethylene

作　　者：倪卓[1] 习雯影[1] 杨松峰[1] 

机构地区：[1]深圳大学化学与化工学院,广东深圳518060

出　　处：《塑料工业》2009年第9期67-71,81,共6页China Plastics Industry

基　　金：广东省科技计划资助项目(2007B010600037)

摘　　要：分别以木糖醇与对甲基苯甲醛、3,4-二甲基苯甲醛、对乙基苯甲醛为合成原料,利用缩醛反应机理,合成了3种不同的木糖醇醛类化合物,包括1,3-2,4-二亚(对甲基)苄基木糖醇(MDBX)、1,3-2,4-二亚(对乙基)苄基木糖醇(EDBX)、二(3,4-二甲基二苄叉)木糖醇(DMDBX)。使用溶液沉淀法制备含有0.3%(质量分数)DMDBX、EDBX、MDBX的聚乙烯(PE)粉末样品。采用X衍射仪、红外光谱仪、偏光显微镜、差示扫描量热仪研究样品的结晶结构和结晶性质。结果表明该类木糖醇醛化合物能够促进PE的异相成核,减小PE球晶尺寸,提高PE结晶度,可以作为PE的结晶成核剂。根据Avram i模型,采用K issinger方程计算了动力学数据。该类成核剂能提高PE的结晶速率,降低活化能。DMDBX成核结晶效果最明显,EDBX其次,MDBX最小。（1, 3-2, 4）-di-（p-methyl-benzylidene） xylitol （MDBX）, （1, 3-2, 4）-di-（p-ethy- benzylidene） xylitol （EDBX） and 1, 3-2, 4-di-（3, 4-dimethyl-benzylidene） xylitol （DMDBX） were synthesized by xylitol and p-methyl-benzaldehyde, 3, 4-dimethyl-benzaldehyde, p-ethyl-benzaldehyde respectively by aldol condensation reation. DMDBX, EDBX and MDBX were introduced into polyethylene （PE） by a solution-precipitation method at a content of 0. 3 % and got PE powder sample. The crystal structures and behaviors of the PE samples were respectively investigated by X-Ray diffractometer, Fourier transform infrared spectrometer （FTIR）, polarized light microscopy, and differential scanning calorimeter. The results showed that xylitol-aldehyde compounds could significantly promote the heterogeneous nucleation of PE, reduce the spherulite size and improve the crystallinity of PE as effective nucleating agents for PE. The crystallization kinetics was then analyzed by using Avrami model and Kissinger equation. The results revealed that this nucleating agent could increase the crystallization rate and reduce the activation energy. The crystal nucleation efficiency was most significant for DMDBX, then EDBX, and the least for MDBX.

关 键 词：木糖醇醛类化合物 聚乙烯 结晶性质 结晶动力学 成核剂 

分 类 号：TQ325.12[化学工程—合成树脂塑料工业]