溶胶-凝胶法聚丙烯酸丁酯/二氧化硅杂化材料弹性体的制备与表征

用丙烯酸丁酯与少量功能单体共聚,合成了分子链侧基带羟基的聚丙烯酸丁酯(PBA)乳液,然后与硅溶胶混合,用溶胶-凝胶法制备了PBA/SiO2杂化材料弹性体;研究了SiO2含量对杂化材料弹性体力学性能及透光率的影响,并用扫描电子显微镜、傅里叶变换红外光谱、差示扫描量热分析和动态力学性能分析对杂化材料弹性体的结构进行了表征。结果表明,PBA/SiO2杂化材料热压后成为一种力学性能优良的具有一定透光率的弹性体。随着SiO2含量的增加,杂化材料弹性体的力学性能提高,透光率和SiO2粒子的粒径增加,PBA基体的玻璃化转变温度和损耗因子下降;PBA共聚物分子链侧基所带羟基与SiO2粒子表面的硅醇基发生了缩合脱水反应,形成了Si—O—C共价键,使PBA基体与SiO2粒子构成的界面结合紧密,从而赋予杂化材料弹性体以优良的性能。

Preparation and characterization of poly(butyl acrylate)/silica hybrid elastomers by sol-gel process

The poly(butyl acrylate)(PBA) latex containing hydroxyl on the side groups of backbone chain was synthesized by emulsion copolymerization with butyl acrylate and a small quantity of functional monomer, and the PBA/silica hybrid elastomers were prepared by sol-gel process with PBA latex and silica sol mixture system. The effects of silica amount on mechanical properties, transmittance of the hybrid materials were studied. The structure of the hybrid elastomers were characterized by scanning electron microscope, Fourier transform infrared spectroscopy,differential scanning calorimetry and dynamic mechanical behavior analysis. The results indicated that PBA/silica hybrid materials became elastomers with excellent mechanical properties and considerable transmittance after hot pressing. As silica contents increasing, the mechanical properties of the hybrid elastomers improved, and the transmittance and silica nanoparticle size increased, while the glass transition temperature and loss factor of PBA matrix decreased. The hydroxyl on the side groups of PBA copolymer chain and the silanol groups on the surface of silica nanoparticles reacted each other via dehydration condensation to form Si-O-C covalent bond, which improved the interfacial interaction between PBA and silica particles effectively, so that the hybrid elastomers were endowed with excellent properties.