聚氨酯与聚丙烯酸酯混合乳液(PU+PA)共聚氯乙烯复合树脂的性能研究

Study on properties of the(PU+PA)/PVC composite resins prepared via copolymerization of polyurethane-polyacrylate hybrid emulsion and vinyl chloride

采用预聚体分散法,以甲苯2,4-二异氰酸酯(TDI)、聚醚(PPG)和二羟甲基丙酸(DMPA)为主要原料,用三乙胺(TEA)为中和剂合成了阴离子水性聚氨酯(PU);以丙烯酸丁酯(BA)为原料,采用乳液聚合的方法制备聚丙烯酸酯乳液(PA),并与PU共混形成(PU+PA)混合乳液。在高压釜中以混合乳液为种子进行氯乙烯(VC)原位共聚,制备了(PU+PA)/PVC复合乳液树脂。通过电子万能试验机、冲击试验机、扫描电子显微镜(SEM)、TA-2000热分析仪和维卡软化点温度测定仪等手段对(PU+PA)/PVC复合树脂进行了测试和表征。结果表明:耐热性较好的PA的加入,不但提高了材料的耐热性能,还能有效地改善复合树脂的抗缺口冲击强度。当PA/PU为4/6,聚醚分子量为3000时,(PU+PA)/PVC复合树脂的缺口冲击强度最大。

Anionic water borne polyurethane （PU） emulsion was prepared with toluene diisocyanate （TDI）, poly- propylene glycol （PPG） and dimethylol propionic acid （DMPA） by prepolymer dispersing process using triethylamine as neutralizer. Polyacrylate （PA） emulsion was prepared from butyl acrylate （BA） by emulsion polymerization technique. Then it was blended with PU emulsion to prepare polyurethane-polyacrylate （PU＋PA） hybrid emulsion. In the presence of the （PU＋PA） hybrid emulsion, the （PU＋PA）/PVC composite resins were obtained by in--situ emulsion copolymerization in an autoclave. The properties of the （PU＋PA）/PVC composite resins were determined via electronic universal testing machine, impact tester, TA-2000-type thermal analyzer and Vicat needle apparatus, respectively. The fractured morphology of the composite resin materials was characterized by scanning electron microscopy. The study results showed that the heat resistance and impact strength of the composite resins were improved when the PA with excellent heat stability was added in. When the proportion of PA and PU prepared from 3000 molecular weight of polypropylene glycol was 4/ 6, the notched impact strength of the （PU＋PA）/PVC composite resin was the greatest.