水性聚氨酯合成中的中和方式对PU/PVC复合树脂性能的影响

Influence of Using Neutralizers in the Preparation of Waterborne Polyurethane on Properties of the PU/PVC Composite Resins

采用预聚体分散法,以甲苯2,4-二异氰酸酯(TDI)、聚醚(PPG-3000)和二羟甲基丙酸(DMPA)为主要原料,分别采用氢氧化钠(NaOH)和三乙胺(TEA)为中和剂合成了阴离子水性聚氨酯(PU)。同时,以PU为种子原位共聚氯乙烯,制备了PU/PVC复合树脂。通过电子万能试验机、冲击试验机、动态力学分析仪(DMA)、扫描电子显微镜(SEM)和TA-2000热分析仪等手段对PU乳液和PU/PVC树脂进行了测试和表征。结果表明:采用TEA为中和剂的乳液其PU的玻璃化转变温度较低,接枝后的复合树脂冲击强度明显提高;不同的中和方式对材料的热稳定性影响较小,采用NaOH中和时热稳定性较好。

Anionic water-borne polyurethane （PU） emulsion was prepared with toluene diisocyanate （ TDI）, polypropylene glycol 3000 （PPG-3000） and dimethylol propionic acid （DMPA） by prepolymer dispersing process. Sodium hydroxide and triethylamine were used as neutralizers respectively. PU/PVC composite resins were prepared by in-situ copolymerization of the PU latex and vinyl chloride monomer. The latex PU and PU/polyvinyl chloride （PVC） composite resins were characterized and determined via electronic universal testing machine, impact testing machine, dynamic mechanical analyzer, scanning electron microscopy （SEM） and TA-2000-type thermal analyzer respectively. The results showed that. while using triethylamine glass transition temperature （Tg） of the PU was lower, and the impact strength of the PU/PVC composite resin was improved significantly, however, the thermal decomposition temperature was higher while using sodium hydroxide as a neutralizer. The influence of the neutralizers was not obvious on heat stability of composite resin materials.