PEGMA改性的光固化水性聚氨酯／二氧化硅纳米复合体系

Synthesis and Properties of UV Curable WPU/SiO_2 Nanocomposites Based on PEGMA Functionalized Colloidal Silica

采用水溶性大分子单体(PEGMA)改性纳米二氧化硅水溶胶(R301-PEGMA),并通过反相乳液法制备光固化水性聚氨酯纳米复合乳液。R301-PEGMA的引入使得复合乳液的粒径和黏度明显增大,透射电镜(TEM)、扫描电镜(SEM)和原子力显微镜(AFM)对复合膜微观结构的分析表明,改性纳米二氧化硅均匀分散在聚氨酯基体和涂层表面,动态力学分析表明,改性纳米二氧化硅可显著提高复合膜储存模量,并且tanδ峰出现明显宽化现象,说明R301-PEGMA与聚氨酯之间存在很强的相互作用。

A water soluble the aqueous colloidal silica （ poly（ethylene glycol） monomethyl ether methacrylate （PEGMA） was used to modify R301-PEGMA）. The waterborne UV-curable polyurethane （WUPU）/12301-PEGMA nanocomposite was prepared by the phase-inversion emulsification method. These composites exhibit the larger particle size and higher viscosity than those of the WUPU dispersion. TEM and SEM measurements show that R301- PEGMA nanoparticles are well dispersed and integrated in the WUPU matrix. AFM measurements further demonstrate that R301-PEGMA nanoparticles are also well dispersed and embedded at the WUPU film.surface. I）MA analysis demonstrates that the WUPU/R301-PEGMA nanocomposite films shows a broadening of the glass transition and has no obvious glass transition for the nanocomposites with 10 % R301-PEGMA, providing the evidence of the strong covalent bonding interactions between the WUPU chain and R301-PEGMA. The PEGMA functionalized nanocomposite fihns displayed enhanced storage modulus, tensile strength without sacrificing high elongation at break compared to those of the WUPU/R-301 nanocomposite films.