Preparation And Performance Study On Eco-friendly Solidified Agent Of Urea-form Aldehyde Resin

As the cost-effecient yet widely-used adhesive, theurea-formaldehyde glue accounts for more than70%of the wood-based panels.Its excessive amouts in free formaldehyde is the major factor of the“decoration disease”for the wood-based panels are the primary materialsof the furnishings and room finishings. As indicated by experts, the adoptof sophisticated production process can reduce the free formaldehydecontent so as to meet the increasingly rigid environmental requirementsand ensure the physical health of the consumers.As for the ratio of the solidifying the urea-formaldehyde resin ofthe low methanal/urea, the low free formaldehyde content in the adhesiveaccounts for the ammonium chloride of the curative impracticable to offerthe acid number required by the resin solidification, which will resultin the malfunction of the slow curing rate, inadequacy and manufacturedproduct; and accordingly, the traditional curative ammonium chloride ishard to fit in with the need of the urea-formaldehyde resin of the lowfree formaldehyde.To meet the requirement of the hardening time and the formaldehyderelease in the building board industry in the progress of modern life andfor the benefit of human health, we’ve in Chapter II proposed the moleculardesigning that synthesizes one sort of copolymerized high moleculecurative composed of acid base group, crosslinking group and freeformaldehyde absorption base, through whose processing condition ofpolyreaction to prepare the multipolymer favorable for the molecular mass.And the utilization of multipolymer1and2has deployed the curativesystem1and2that provides the prerequisite for the performance of thesolidification and absorption during the hard dry of the wood-based panels.Chapter III discusses the new-styled curative system necessary forthe composite interpolymers and other curing agents, and also for theformulated ratio and compounding recipe. The study reveals that such atest on the hot pressboard nature and the detailed study on theformaldehyde release has improved clearly in the aspect of curing velocityand burst size as compared with the base polymer. After the adoption ofthe chain-transfer agent, the controlled ratio of acrylic acid, acrylicamide and methylol acrylamide is3：6：1, and the curing agent availablepossesses the shortest curing time and the lowest methanal release, themean time being shortened to4-7sec.