丙烯酸固相接枝制备高稳定性改性聚乙烯蜡微乳液

Preparation of modified polyethylene wax micro-emulsion with high stability by solid phase grafting of acrylic acid

旨在对低密度聚乙烯蜡进行化学接枝改性,改善其可乳化性能,从而制备高稳定性改性聚乙烯蜡微乳液。首先以丙烯酸作为接枝单体,采用悬浮溶胀接枝法对低密度聚乙烯蜡进行化学接枝改性;然后,通过选取适当的阴离子乳化剂和非离子乳化剂的复配体系,对接枝改性的聚乙烯蜡产物进行乳化。结果表明：采用SDS和Tween80等比例复配,控制乳化温度为90~95℃,乳化剂用量为聚乙烯蜡的10%、乳化时间为30min时,采用相转变乳化法可制得高稳定性的聚乙烯蜡微乳液。采用FTIR对改性聚乙烯蜡进行了结构表征,证明了丙烯酸被成功地接枝到了聚乙烯蜡分子上,并通过DSC分析研究了其熔点和结晶情况的变化：聚乙烯蜡的熔点为102.41℃,丙烯酸接枝改性聚乙烯蜡的熔点为102.85℃;改性聚乙烯蜡与未改性的聚乙烯蜡的比结晶度为77.7%。

In order to improve the emulsifying property of low density polyethylene wax,we prepared modified polyethylene wax micro-emulsion with high stability via chemical grafting modification. First,chemical grafting of low density polyethylene was successfully realized by the suspension-swelling graft method using acrylic acid as grafting monomer. Then,with selected reconstituted anionic and non-ionic emulsifier,and under the conditions of emulsion temperature between 90~95 ℃,emulsifier dosage of 10% polyethylene wax and emulsification for 30 min,micro-emulsion of polyethylene wax with high stability was prepared by a phase change emulsion method. Structure of the modified polyethylene wax was characterized by FTIR,which identified that acrylic acid was successfully grafted to the polyethylene wax molecules. Its melting point and crystallization behaviors were also studied via DSC technology. The melting points of the modified polyethylene wax and the original polyethylene wax are 102.85℃ and 102.41℃,respectively,and their crystallinity ratio was 77.7%.