纳米SiO2改性醇溶性蓖麻油-聚氨酯树脂的制备与表征

Synthesis and Characterization of Alcohol-soluble Polyurethane Modified by Castor Oil and Nano-SiO2

摘要:

利用端氨基偶联剂KH-550对纳米SiO2进行表面改性，在超声场作用下制备疏水性纳米二氧化硅粒子，并将其均匀分散到蓖麻油(CO)制备的聚氨酯溶液，通过红外光谱 (IR)、热重分析(TGA)和扫描电镜(SEM)等测试方法探讨醇溶性聚氨酯的稳定性、乳液的粒径分布等性能和结构的关系。红外分析表明：PU大分子和纳米SiO2之间形成化学键，形成了Si-O-Si结构。当m(蓖麻油)：m(聚醚N210)=1:9时，拉伸强度由原来的6.8 MPa增加到16.2 MPa，吸水率也提高了2倍多。纳米SiO2颗粒掺杂量由0%增加到2%时,PU涂膜的失重速率最高点温度由原来的345℃提高至369℃，热分解温度也有所提高。涂膜热重曲线出现右移。

Abstract:

Hydrophobic nano-SiO2 particles were prepared from reacting coupling agent KH-550 and nano SiO2 particles in the ultrasound, and dispersed in polyurethane solution modified by castor oil (CO). The performances of polyurethane were characterized by Fourier transform infrared (FT-IR) spectroscopy, thermal gravimetric analysis (TGA) and scanning electron microscopy (SEM). The FT-IR analysis indicates the formation of chemical bond between PU and nano-SiO2, and formed the Si-O-Si particle structure. As m(CO)：m(N210)=1:9 the tensile strength o f the films increased from 6.8 MPa to 16.2 MPa. The water absorption also increased two times. As the mass fraction of nano-SiO2 increased from 0 to 2%, the initial weight loss temperature of the PU films increased from 255 e to 272 e. The films performance is better, greatly improve the mechanical properties, water resistance and heat resistance.