苯乙烯-乙烯-丁二烯-苯乙烯嵌段共聚物的功能化与反应共混的研究

采用3-异丙烯基-α,α′-二甲基苄基异氰酸酯(TMI)对苯乙烯-乙烯-丁二烯-苯乙烯嵌段共聚物(SEBS)进行自由基溶液接枝功能化。纯化后的接枝产物(SEBS-g-TMI)的傅里叶变换红外光谱分析表明,异氰酸酯单体已经接枝到SEBS上。异氰酸酯功能团间强烈的相互作用使得SEBS-g-TMI的表观黏度高于SEBS且随接枝率的增加而增加,在同样的剪切应力下,SEBS-g-TMI的表观黏度比SEBS高约2个数量级。与相应的SEBS/PA6相比,SEBS-g-TMI/PA6反应共混体系的冲击强度随着接枝率的提高而增加,可以作为PA6有效的增韧剂。

PREPARATION OF ISOCYANATE FUNCTIONALIZED STYRENE-ETHYLENE-BUTADIENE-STYRENE COPOLYMER AND ITS BLENDING WITH POLYAMIDE 6

Styrene-ethylene-butadiene-styrene copolymer(SEBS) was radically functionalized with 3-isopropenyl -alpha,alpha-dimethylbenzyl isocyanate(TMI) in solution.FTIR analysis confirmed the formation of SEBS-g-TMI.The peak at 2 256 cm~(-1),characteristic of—NCO groups in SEBS-g-TMI, revealed the evidence of grafting occurrence.Due to the intensive interaction between—NCO groups, the apparent viscosity of SEBS-g-TMI is much higher than that of SEBS and increased with increasing the grafting degree of TMI.The apparent viscosity of SEBS-g-TMI is approximately increased by two orders of magnitude,compared with that of SEBS under the same shear stress.Comparison with the blends obtained from ungrafted SEBS and PA6 shows that impact strength of SEBS-g-TMI/PA6 is dramatically enhanced,which is strongly dependent upon the grafting degree of TMI,indicating that isocyanate functionalized SEBS can act as potential compatibilizer for PA6.