摘要
利用差示扫描量热法结合Avrami方程研究了苯乙烯-乙烯．丁烯．苯乙烯嵌段共聚物接枝马来酸酐fSEBS．g-MAH）对线型低密度聚乙烯（LLDPE）等温及非等温结晶动力学的影响。结果表明，热塑性弹性体SEBS及其接枝物的加入阻碍了LLDPE分子链的规则排列，影响了链段在结晶扩散迁移规整排列的速度，使得结晶速率变慢，对LLDPE晶体生长起了抑制作用；LLDPE／SEBS．g．MAH共混体系的半结晶时间t1/12和结晶活化能AE明显增大，Avrami指数，t对结晶温度有依赖性，k值随温度的升高而减小。通过Jeziomy法对非等温结晶过程进行处理，试样的Avrami指数n值均在1．1～1．5，表明LLDPE的结晶成核机理和生长方式没有改变。
The influence of SEBS-g-MAH addition on isothermal and nonisothermal crystallization kinetics of LLDPE was studied with differential scanning calorimentry combined with the Avrami equation. The results show that, due to partial destruction of crystal region, the crystallization rate of LLDPE decreases with adding SEBS and its grafts. Addition of elastomer plays a inhibition for crystal growth of LLDPE. The isothermal crystallization process was described by Avrami equation and the Avrami exponent n is related with the crystallization temperature. It was found that the half crystallization time （t1/2） of LLDPE/SEBS-g-MAH is much longer than that of pure LLDPE, the activation energy of crystallization （△E） increases and the value of kn decreases with increasing crystallization temperature. The methods of Jeziorny for non-isothermal crystallization kinetics was used to analyze the crystallization characteristics, the results demonstrate that all samples have Avrami exponents in the range of 1.1- 1.5, it implies that the nucleation mechanism and geometry of crystal growth of LLDPE have no change.
出处
《高校化学工程学报》
EI
CAS
CSCD
北大核心
2012年第2期235-240,共6页
Journal of Chemical Engineering of Chinese Universities
关键词
LLDPE
SEBS-G-MAH
差示扫描量热法
等温结晶动力学
非等温结晶动力学
LLDPE （linear low density polyethylene）
SEBS-g-MAH （styrene-ethylene-butene-styrene block copolyiners grafted maleic anlydride）
DSC
isothermal crystallization kinetics
non-isothermal crystallization kinetics
