A novel route for improving creep resistance of polymers using nanoparticles

In the present work, a one-step approach was suggested for improving creep resistance of thermoplastic polymers using nanoparticles. That is, SiO2 nanoparticles were pretreated by silane coupling agent to introduce reactive CC double bonds onto their surfaces. Afterwards, in the melt mixing with matrix polypropylene (PP), butyl acrylate monomers reacted with the silane coupling agent on the nanoparticles and then crosslinked to interconnect the particles with each other, while the PP chains penetrated into the networks, forming semi-interpenetrating polymer network (semi-IPN) structure. Taking the advantage of the specific microstructure, the nanoparticles were well distributed in the matrix with enhanced interfacial interaction. As a result, mobility of the matrix molecules was restricted to certain extent, and creep resistance of the nanocomposites became much higher than those of untreated nano-SiO2/PP system and unfilled PP as well.