Effects of nano manganese dioxide on performances of urea-formaldehyde resin

Abstract

In cured urea-formaldehyde (UF) resin with low molar ratio of formaldehyde/urea (F/U), existent crystalline regions are believed to affect the properties of wood-based composites bonded with UF resins. The effects of crystalline regions on physicomechanical properties and formaldehyde emission of the plywood bonded with UF resin modified by nano Manganese dioxide (MnO₂) were studied in this work. Results show that the modified UF resins with 0.9% MnO₂ has a higher ratio of crystalline regions than those of neat resins. They resulted in a 79% improvement in the wet shear strength and a 70% reduction in the formaldehyde emission. The X-ray diffraction (XRD) results show that the crystallinity in the cured UF increases with the amount of MnO₂ added. No change in the structure of the cured UF was found in the Fourier transforms infrared spectroscopy (FT-IR) with the addition of MnO₂.

Keywords:

• Nano
• manganese dioxide
• urea-formaldehyde
• resin

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the National Natural Science Foundation of China (No. 31800481), Yunnan Fundamental Research Key Projects (2019FA012).