聚醋酸乙烯酯/蒙脱土纳米乳液的性能影响因素

Study on performance factors of polyvinyl acetate/montmorillonite nano-composite emulsion

基于单体原位插层半连续乳液聚合法,制备了涂料用聚醋酸乙烯酯/蒙脱土纳米复合乳液,对影响纳米复合乳液性能的反应温度、乳化剂用量、引发剂用量以及MMT质量分数进行了单因素研究.XRD,FT-IR和TEM分析结果表明：65-70℃条件下,当乳化剂用量0.6 g,引发剂用量0.6g以及MMT质量分数为3%-5%时,MMT片层在PVAc基体中基本呈单分散状,形成了剥离型纳米复合材料,其纳米化程度最大,乳液MMT单片层的数量最多;此时MMT的分散程度最高、阻隔性能最好,大大降低了水的扩散速度与吸水率,延长了耐水时间.测试表明：乳液质量分数达到33%-35%,静置于水中135 h胶膜不开胶脱落,其耐水性能是PVAc乳液（不含MMT）的2.7倍.

Polyvinyl acetate/Montmorillonite nanocomposite emulsions were prepared by means of in-situ semi-continuum intercalation polymerization.The composite emulsions were characterized by X-ray diffraction,FT-IR and transmission electron microscopy.The effects of the initiator,reaction temperature,emulsifier and MMT dosage on the performance of emulsions were studied by mono-factor experiments.The results showed that,under the 65~70 ℃ reaction condition,when both the emulsifier and initiator′s dosage were 0.6 g,and MMT dosage was 5% of the monomer quantity,MMT layers in the PVAc matrix monodispersed basic shape were formed as exfoliated nanocomposites.At this point the highest degree of dispersion of MMT is reached,the barrier properties are the best,and the rates of water diffusion and water absorption are significantly reduced.The tests showed that its solid content attained 33%～35% and the water resistance was improved by 2.7 times compared to common PVAc emulsions.