Strengthening Network of Polyacrylic Acid/Silica Nanocomposite Hydrogels

The polyacrylic acid (PAA)/silica nanocomposite hydrogels with high mechanical property were prepared by combining sol‐gel process and in situ free radical polymerization using 3‐methacryloxypropyltrimethoxysilane (MPTMS) as silane and acrylic acid (AA) as monomers. The structure‐property relationship of nanocomposite hydrogels was characterized by FT‐IR, DMA, TGA, XRD, TEM, and static mechanical testing. The dependence of mechanical property on the network parameter was investigated. The elastic modulus and compression fracture stress of PAA/silica nanocomposite hydrogels reached 1.27 and 1.35 MPa at molar ratio of MPTMS to AA of 0.034. The enhancement of mechanical property was attributed to the multiple cross‐linking networks between MPTMS and AA by covalent bonding and hydrogen bonding. POLYM. COMPOS., 39:3969–3976, 2018.