Preparation and properties of waterborne poly(urethane acrylate)/silica dispersions and hybrid composites

Abstract

The waterborne polyurethane acrylate (PUA) dispersion was prepared based on polyester polyol, isophorone diisocyanate, dimethylol propionic acid, butyl acrylate and trimethylolpropane triacrylate. Then, a series of PUA/SiO₂ hybrid dispersions were prepared from PUA dispersion, coupling agent 3-glycidyloxypropyl trimethoxysilane and different content tetraethoxysilane hydrolysis solutions by the sol–gel process. The physical properties of PUA/SiO₂ hybrid dispersions and the mechanical properties of PUA/SiO₂ hybrid composites were measured. The PUA/SiO₂ hybrids were characterised. The results showed that the nano-SiO₂ particles of the hybrids had good dispersion and formed a good interfacial bonding layer on its surface. When the tetraethyl orthosilicate content was 0·5 wt-%, the hybrid film exhibited excellent comprehensive mechanical properties and water resistance. The tensile strength, hardness and water absorption of the film were 3·32 MPa, 90 and 6·7% respectively. The obtained PUA and hybrid composites have great potential application, such as coatings, leather finishing, adhesives, sealants, plastic coatings and wood finishes.