Fabrication of NCC-SiO2 hybrid colloids and its application on waterborne poly(acrylic acid) coatings

Nanocrystalline cellulose and nano SiO2 (NCC-SiO2) hybrid colloid was synthesized by in situ polymerization using a template of NCC. The prepared NCC-SiO2 hybrid colloid was then introduced to waterborne poly acrylic acid (PAA) coatings. NCC template could inhibit an aggregation of nano SiO2, leading to a uniform distribution of SiO2 in PAA coatings. Furthermore, a formation of crosslink network of hydrogen bonding improved interfacial compatibility in a system of NCC, SiO2 and PAA. Compared to the individual NCC and nano SiO2, NCC-SiO2 hybrid colloid had an obvious improvement on the mechanical performance and the transmittance of waterborne PAA coatings. With 5 wt% NCC-SiO2 hybrid colloid, PAA coating had maximum mechanical properties, with corresponding to 6H in hardness, and level-0 in adhesion, respectively. Moreover, PAA coatings with 5 wt% NCC-SiO2 hybrid colloid had a higher transmittance of 41.8% at 390 nm.