Abstract
Inordertoanalyzethecuringprocessofurea-formaldehyde(UF)resin,thedynamicviscoelasticityand'''C-NMRspectraoftheUFresinsynthesizedundervariousconditionsweremeasured.Furthermore,theeffectofchemicalstructurechangesoftheUFresinontheformaldehydeemissionfromplywoodwasexamined・Theexperimentalresultsshowedthattherelativerigidity(G;/Go)oftheUFresinwasnearlyconstantinthetemperaturerangeofT,toT,.ItwasestimatedfromtheG//GovaluethatwhentheUFresinwassynthesizedwithhighformaldehyde/urea(F/U)molarratio,thecross-linkedstructurewasformedbytheliquid-to-rubbertransformationintheUFresin.WhentheUFresinwithhighF/Uratiowascuredat115℃,arelativelyhigheramountofdimethyleneetherbondandmethylolgroup,whichareeasilyhydrolyzed,andmethyleneglycolwerefoundinthecuredresins.Accordingly,itwassuggestedthattheamountofformaldehydeemissionfromtheplywoodincreasedalongwiththeincreaseofF/Uratioowingtotheformationofeasilyhydrolyzedfunctiongroupsandincludingmethyleneglycolinthegelledrubberresin.
