Application of Nano-SiO 2 Reinforced Urea-Formaldehyde Resin and Molecular Dynamics Simulation Study.

Nano-SiO 2 is a typical modifier used for urea-formaldehyde (UF) resins to balance the reduced formaldehyde content and maintain bond strength. However, the microstructure of UF resin and the interaction between UF resin and nano-SiO 2 are microscopic phenomena; it is difficult to observe and study its intrinsic mechanism in traditional experimental tests. In this work, the enhancement mechanism was explored by molecular dynamics simulations combined with an experiment of the effect of nano-SiO 2 additions on UF resin. The results showed that the best performance enhancement of UF resin was achieved when the addition of nano-SiO 2 was 3 wt%. The effects caused by different additions of nano-SiO 2 were compared and analyzed by molecular dynamics simulations in terms of free volume fraction, the radius of gyration, and mechanical properties, and the results were in agreement with the experimental values. Meanwhile, the changes in hydrogen bonding and radial distribution functions in these systems were counted to explore the interaction between nano-SiO 2 and UF resin. The properties of the UF resin were enhanced mainly through the large number of different forms of hydrogen bonds with nano-SiO 2 , with the strongest hydrogen bond occurring between H (SiO2) … O = (PHMU) .