Application of Nano-SiO₂ Reinforced Urea-Formaldehyde Resin and Molecular Dynamics Simulation Study

Abstract

Nano-SiO2 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-SiO2 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-SiO2 additions on UF resin. The results showed that the best performance enhancement of UF resin was achieved when the addition of nano-SiO2 was 3 wt%. The effects caused by different additions of nano-SiO2 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-SiO2 and UF resin. The properties of the UF resin were enhanced mainly through the large number of different forms of hydrogen bonds with nano-SiO2, with the strongest hydrogen bond occurring between H(SiO2)… O = (PHMU).

Keywords

• urea formaldehyde resin
• nano-SiO₂
• modification
• molecular dynamics simulation