Abstract
Toexplorethepossibilityofutilizingsilkfibroin(SF)asawoodadhesiveandtoimprovethewaterdurabilityoftheSFbytheadditionofanaqueousemulsion-typeisocyanateresin(EIC),acompressivesheartestandcharacterizationofthefilmpreparedfromEICandSFwereconductedThebondstrengthofSFdidnotdecreaseinspiteofimmersionin30℃waterfor3hours.ThebondstrengthwasmodifiedwithanincreaseintheEIC/SFratios,althoughwoodfailureofallspecimenswerelessthan10%withimmersionofthespecimensin60℃hotwaterfor3hoursTheresultsoftensiletestofEIC/SFfilmssuggestedthatthelowerwoodfailurewascausedbyadecreaseinthecohesionforceoftheadhesivelayerbysorptionofwater.TheglasstransitiontemperatureofEIC/SFfilmsshiftedtoalowertemperatureandthethermalexpansioncoefficientincreasedastheEIC/SFratioincreased.Consequently,thecrystalformationofsilkfibroinincludingsilkIIformationservesasthehardsegmentoftheEIC/SFfilmsandEICthatreactedwithwaterorpolyolsincludedindenaturedEICservesasthesoftsegment
