反应挤出制备CDP/PA6共混物:相容性改善及其机理研究

Extruded benzene sulfonate modified poly(ethylene terephthalate)/polyamide 6 blends:An insight into the mechanism of compatibility improvement

针对聚对苯二甲酸乙二醇酯(PET)和聚酰胺6(PA6)共混后相容性差的问题,提出了以苯磺酸盐改性PET(CDP)和PA6为原料,在双螺杆挤出机中制备CDP/PA6共混物。结果表明,所得到的共混物分散相尺寸小、形状不规则,两相相容性远好于PET/PA6共混物。相容性改善机理为:CDP链中引入的苯磺酸基团是酯-酰胺交换反应的有效催化剂,其与PA6的酰胺键一步反应,快速生成聚酯/聚酰胺接枝共聚物,在短短几分钟内大大提高了聚酯与聚酰胺的相容性。当CDP/PA6共混物中CDP与PA6的质量分数相近时,聚酯与聚酰胺互相渗透程度大大提高,并形成双连续相。

In order to solve the problem of poor compatibility of polyethylene terephthalate(PET)and polyamide 6(PA6)blends,the blends were prepared in a twin-screw extruder using benzene sulfonate modified PET(CDP)and PA6 as raw materials.The results show that the CDP/PA6 blend has a dispersed phase with small size and irregular shape.Its compatibility is far better than that of PET/PA6 blends.The mechanism of the increased compatibility is revealed as follows:the benzenesulfonate group incorporated in the CDP chain is an efficient catalyst for ester-amide exchange,and its one-step reaction with the amide link in PA6 can rapidly produce polyester/polyamide graft copolymers,which greatly improves the compatibility between polyester and polyamide in a few minutes.When the contents of CDP and PA6 in the CDP/PA6 blend was similar,the degree of mutual penetration between polyester and polyamide can be greatly improved that lead to a co-continuous morphology.