Preparation, characterization, and properties of sodium montmorillonite clay/poly(styrene–butadiene–styrene) containing quaternary ammonium cations and photoinitiator nanocomposites via ultraviolet exposure

A functionalized graft copolymer {poly(styrene–butadiene–styrene) (SBS)‐g‐4‐benzoyl‐N,N‐dimethyl‐N‐[2‐(2‐methyl‐1‐oxo‐2‐propenyloxy)ethyl]benzenemethanaminium bromide (4‐BBPDMAEMA)}, containing a photoinitiator, quaternary ammonium cations, and many CC double bonds, was synthesized to modify clays, such as Na+–montmorillonite (MMT) clay, for the preparation of organic–inorganic nanocomposite resins via radical photoinduced crosslinking polymerization. The structure of SBS‐g‐4‐BBPDMAEMA was characterized by Fourier transform infrared and 1H‐NMR spectroscopy. The corresponding SBS‐g‐4‐BBPDMAEMA was found to have two functions: the capability to ionically exchange with sodium ions in the silicate gallery and the capability to synthesize exfoliated SBS/MMT nanocomposites by the UV crosslinking of intercalation polymerization. The results from the X‐ray diffraction primarily reveal that the clay platelets should have been exfoliated or completely disordered. However, the results from transmission electron microcopy confirmed that a mixture of partially exfoliated and intercalated structures presented in the nanocomposites. Dynamic mechanical thermal analysis testing indicated that the glass‐transition temperature of the polybutadiene phase and polystyrene phase moved to a lower temperature. Data of thermogravimetric analysis and testing of the mechanical properties showed that the thermal stability and mechanical properties of SBS‐g‐4‐BBPDMAEMA could be regulated by the crosslinking and content of MMT.