Dialdehyde starch reinforced polyacrylate-polyethylene glycol resin for impregnated decorative paper with improved toughness and ultra-low formaldehyde emission

To solve the problems of brittleness and formaldehyde emission of melamine-formaldehyde (MF) impregnated decorative paper, a polyacrylate-polyethylene glycol (PEG)-dialdehyde starch (DAS) was used to modify MF. The impregnation adhesive was characterized and the properties of impregnated decorative paper and laminated to plywood were tested. DAS showed better dispersion in the compound resin and higher reactivity with MF compared to the control. The MF can react with active aldehyde groups of DAS by Schiff base reaction and hydroxyl groups of polyacrylate, PEG, and DAS. Thus, the cross-linked structure was formed in the impregnated decorative paper interlayer. At mass ratio of polyacrylate-PEG-DAS:MF= 2:1, the abrasion value, surface bonding strength, fouling capacity of plywood was comparable to MF impregnated decorative paper bonded plywood, improved with crack resistance. In addition, the formaldehyde emission was sharply lowered down with ultra-low value of 0.03 mg/L, which was classified as F* ** * for very high JAS 234:2003 standard (≤0.3 mg/L).