醋酸纤维素/PET接枝共聚物的制备及性能

以低数均分子量的聚对苯二甲酸乙二醇酯(PET)、二醋酸纤维素(CDA)为原料,异孚尔酮二异氰酸酯(IPDI)为接枝剂,二月桂酸二丁基锡(DBTDL)和离子液体1-丁基-3-甲基咪唑氯盐为催化剂制备得到新型的接枝共聚物CDA-g-PET。对接枝过程进行了优化,研究了催化剂种类与接枝剂用量对接枝过程的影响,利用红外分析和广角X射线衍射分析探究了接枝机理。同时对CDA-g-PET膜进行力学性能测试,探讨了PET的加入量对CDA-g-PET膜力学性能的影响。结果表明:PET通过化学键连接接枝到CDA上,接入的PET降低了CDA的结晶性;采用DBTDL与离子液体作为联合催化剂,接枝时间由7d缩短至8h;当接枝剂IPDI的加入量,即n(IPDI)/n(PET)为1.05~1.10时CDA-g-PET无交联;随着PET含量的增加,CDA-g-PET膜与CDA膜相比拉伸强度仅降低6.55%~27.24%,断裂伸长率增加149.89%~177.81%。

Preparation and Properties of Cellulose Acetate Grafted PET

A new grafting product CDA-g-PET was synthesized using polyethylene terephthalate (PET) with low molecular weight and cellulose diacetate (CDA) as raw materials, isophorone diisocyanate (IPDI) as grafting agent and dibutyltin dilaurate (DBTDL),1-butyl-3-methylimidazolium chloride as grafting promoter.The grafting process was optimized via exploring the type of catalyst and the amount of grafting agent.The mechanism of grafting was explored by Fourier infrared spectroscopy and wide angle X-Ray Diffraction (XRD) analysis.Furthermore, the mechanical property of CDA-g-PET film was influenced by the content of PET.The results show that PET is grafted onto CDA by chemical bond linking, and reduces the crystalline of CDA.Grafting time decreases to 8 h from 7 d due to DBTDL and ionic liquids as combined catalyst.When the amount of grafting agent for n(IPDI)/n(PET) is 1.05~1.10, there is no crosslinked CDA-g-PET found.With the increase of PET content, the tensile strength of CDA-g-PET film decreases by 6.55%~27.24% and the elongation at break increases by 149.89%~177.81% compared with CDA film.