The influence of hydrogen bond and electrostatic interaction on the mechanical properties of the WPU/modified SiO2 nanocomposites

A variety of nano SiO 2 microspheres with negative charge or positive charge were prepared by hydrochloric acid treatment or/and γ-mercaptopropyltrimethoxysilane modification respectively. The obtained modified SiO 2 with different content of -OH or -SH and different charges were physically introduced into water-borne polyurethane (WPU) dispersion to fabricate the WPU/modified SiO 2 nanocomposites with interfacial interaction of hydrogen bond and electrostatic interaction . The influence of interfacial interaction (hydrogen bond and electrostatic interaction) between WPU and modified SiO 2 on the interface structure and mechanical properties of the WPU/modified SiO 2 nanocomposites were investigated. The results showed that when both hydrogen bond and electrostatic interaction were present between WPU and modified SiO 2 , the microstructure and the tensile strength of the WPU/modified SiO 2 nanocomposite were mainly affected by the electrostatic interaction, while the elongation at break was mainly affected by the hydrogen bond interaction. Overall, a methodology of the combination of molecular dynamics simulation and experiment study was established to reveal the influence of surface characteristic of SiO 2 on the interface interaction and mechanical properties of the WPU/modified SiO 2 nanocomposites.