Curing properties study on sucrose-melamine-formaldehyde resin

Abstract

Melamine formaldehyde resin (MF) has a long history of about 90 years since its birth. Its industrial application, however, has been limited by the high cost of raw materials, high content of free formaldehyde and easy cracking of adhesive layer after curing. These problems can be solved by making use of biomass resources to modify MF in theory. Sucrose, melamine and formaldehyde were noted as the main raw materials for synthesizing sucrose-melamine-formaldehyde copolymer resin (SMF) under alkaline conditions. The effect of sucrose content and curing agent on the curing properties have been carried out through Fourier transform-infrared spectroscopy (FT-IR), nuclear magnetic resonance spectrum (NMR), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The findings show that the SMF curing behavior was an exothermic process, which was achieved by the dehydration synthesis between hydroxymethyl groups. The sucrose content had a large effect on the thermal stability and the curing behavior of SMF, and the addition of curing agent promoted the resin curing. Not only was the thermal stability decreased, but also the curing reaction was more difficult to occur with the sucrose addition. The sucrose molecules participated in the curing process through chemical bonding, and then formed a stable network structure for the resin system.