Study On Preparation Of Single-component Polyvinyl Acetate D3-leveled Wood Adhesive

D3-leveled wood adhesive has been widely used for its excellent performance inwater resistance and high practical value.Its two-component type causes muchinconvenience in transport,package and application.Isocyanate,as one of the maincomponent of D3-leveled wood adhesive,is of high price and hazardous to health.Vinylacetate is low-cost and suitable for being modified,also has no harm toenvironment.Some successful studies have been achieved to improve the performace ofPVAc through copolymerization or crosslinking.The study progress of D3-leveled wood adhesive has been associated with thedevelopment status of polyvinyl acetate in the study.The paper introduces the theories ofproducing a single-component D3-leveled wood adhesive by modifying the performanceof vinyl acetate, and also analyzes the research ahievements.It includes:(Ⅰ)The reaction mechanism and molecular structure of polymers were analyzedand speculated.(Ⅱ)PVA was modified with glyoxal as protective colloid for polyvinyl acetate.Theeffect of pH and temperature on performance of G-PVA,acetal degree on waterresistance were discussed.The results proved that when pH wass2.0and reactiontemperature was75℃,G-PVA could achieve good performance.(Ⅲ)Latex particles of the adhesive with core-shell was achieved by using EVAemulsion as seed,and G-PVA as protective colloid. FT-IR curve showed that structure ofthe polymer was the same as theoretical designation.The glass temperature of thepolymer is6.2℃according to DSC analysis.(Ⅳ) The type of initiator and emulifier was analyzed.The effcet of seed,protectivecolloid,copolymer monomer VeoVa-10,ketone hydrazine cross-linked system andreaction temperature on performance of adhesive were discussed systematically.Theperformance of the adhesive attained was tested and appraised according the DIN EN204D3-leveled standard of waterproof wood adhesive.The test proved that performanceof the adhesives achieved could meet the requirement of D3-leveled wood adhesive.Itcan be well applied for its advantage of low cost,convinence and environment favorble.