纳米SiO2/有机硅改性水性聚氨酯复合材料的制备及性能

为了改善水性聚氨酯（WPU）耐水性差和表面性能差等缺陷，将有机硅和纳米SiO₂同时引入到WPU中，首先通过自乳化法制备了WPU和有机硅改性水性聚氨酯（SWPU）。然后采用超声共混法将纳米SiO₂粒子加入到SWPU中，制备了纳米SiO₂/SWPU复合材料。最后，采用FTIR和SEM对WPU、SWPU和纳米SiO₂/SWPU的结构进行了表征，通过接触角、吸水率及抗拉力学性能测试分析了WPU、SWPU和纳米SiO₂/SWPU的疏水性能及抗拉力学性能。结果表明：纳米SiO₂已被成功引入到SWPU中；纳米SiO₂含量较小（≤3wt%）时能够较均匀地分散在纳米SiO₂/SWPU胶膜中；当纳米SiO₂含量从0增大至5wt%时，纳米SiO₂/SWPU胶膜的吸水率降低了69%，拉伸强度从16.72 MPa增大至24.22 MPa，断裂伸长率从545%增至731%，表明纳米SiO₂的引入显著提高了SWPU胶膜的耐水性能和力学性能。

Preparation and properties of nano-SiO2/organosilicon modified waterborne polyurethane composites

In order to improve the water resistance and poor surface property of waterborne polyurethane (WPU), organosilicone and nano-SiO₂ were introduced into the WPU. First, WPU and organosilicon modified waterborne polyurethane (SWPU) were synthesized by self-emulsified method. Then, nano-SiO₂/SWPU composites were prepared by adding SiO₂ particles into SWPU using ultrasonic blending method. Finally, the structures of WPU, SWPU and nano-SiO₂/SWPU were characterized by FTIR and SEM, and their hydrophobicity and mechanical properties were analyzed by water contact angle measurement, water absorption and elongation mechanic test. Results show that nano-SiO₂ is successfully introduced into SWPU. Nano-SiO₂ could disperse uniformly in the film of nano-SiO₂/SWPU when nano-SiO₂ content is low (≤3wt%). When the content of nano-SiO₂ increases from 0 to 5wt%, the water absorption of nano-SiO₂/SWPU film decreases by 69%, the tensile strength increases from 16.72 MPa to 24.22 MPa, while the break elongation increases from 545% to 731%, which show that the introduction of nano-SiO₂ significantly improves the water resistance and mechanical properties of SWPU.