纳米TiO_2/PSB复合乳液的制备与性能研究

Study on Preparation and Performance of Nano-TiO_2/PSB Composite Latex

为了提高丁苯乳液涂膜力学性能,用硅烷偶联剂(KH-570)改性纳米TiO2,采用半连续种子乳液聚合法,制备TiO2/聚丁苯(PSB)复合乳液。采用FT-IR、TEM表征TiO2/PSB复合乳液乳胶粒子结构,结果表明合成了以TiO2为核的核壳结构纳米TiO2/PSB乳胶粒子。探讨了纳米TiO2、乳化剂、电解质、引发剂及增稠剂用量、聚合时间与温度、单体配比等对TiO2/PSB复合乳液性能的影响。确立了适宜的聚合工艺条件:纳米TiO2、乳化剂用量分别为总质量的0.5%和3.5%,电解质和引发剂用量为单体质量的0.4%,聚合温度和时间分别为64℃和3.5 h,可制备出高固高黏且性能优良的复合乳液。经纳米TiO2改性的PSB复合乳液涂膜性能较未改性的,在黏度、硬度、耐冲击性、耐洗刷性、附着力及耐水性等方面均有明显改善。

Based on nano -TiO2 modified by silane coupling agent （KH -570） as modifier, nano - TiO2/polyslyrene- buladiene （PSB） composite emulsion was prepered by semi -continuous seed emulsion polymerization process to improve mechanical propmlies of polymer styrene - butadiene latex coating. The nano latex particles of core - shell structure with TiO2 as the content were characterized by FT - IR and TEM. The factors that affect the performance of TiO2/PSB composite latex were investigated, such as the content of nano - TiO2, emulsifier, electrolyte, initiator and thickener, polymerization temperature and time, the proportion of monomer. The optimal polymerization conditions were established： the content of nano - TiO2 , emulsifier, electrolyte, initiator were 0. 5% , 3.5% , 0. 4% and 0. 4% respectively, and polymerization temperature and time were 64 ℃ and 3.5 h. A good performance high solid and high viscosity composite latex was prepared. Compared with the coating performance of PSB composite emulsion unmodified, its coating performance modified by nano - TiO2 have been improved greatly in terms of viscosity, hardness, impact strength, washability and adhesion.