纳米SiO_2改性水性聚氨酯乳液的制备及性能研究

以硅烷偶联剂(KH-550)作为纳米二氧化硅(nano-SiO2)的表面处理剂,以甲苯二异氰酸酯(TDI)、聚醚二元醇(N-220)、二羟甲基丙酸(DMPA)和nano-SiO2等为主要原料,制备nano-SiO2改性WPU(水性聚氨酯)乳液。着重探讨了DMPA的加料方式、DMPA和nano-SiO2用量等对WPU乳液稳定性、粒径分布、耐水性和力学性能等影响。结果表明:采用先加入DMPA后扩链的加料方式,可制得外观及稳定性均较好的WPU乳液;当w(DMPA)=5%、w(改性nano-SiO2)=2.0%时,WPU乳液及其胶膜的综合性能较好。

Study on preparation and properties of waterborne polyurethane emulsion modified by nano-SiO2

With toluene diisocyanate(TDI),polyether diols(N-220),dimethylolpropionic acid(DMPA) and nano-SiO2 as main raw materials,and silane coupler(KH-550) as surface treatment agent of nano-SiO2,a WPU(waterborne polyurethane) emulsions modified by nano-SiO2 was prepared.The influences of some factors such as feeding mode of DMPA,contents of DMPA and nano-SiO2 on stability,particle size distribution,water resistance and mechanics properties of WPU emulsion were emphatically discussed.The results showed that the WPU emulsion with better appearance and stability could be obtained by feeding mode of adding DMP before chain extension reaction.The WPU emulsion and its film had better combination property when mass fractions of DMPA and modified nano-SiO2 were 5% and 2.0% respectively.