Autor(es): Aguiar, A ; Marcelino, L.P. ; Mariquito, A ; Simões, C.L. ; Simoes, Ricardo ; Pinho, Isabel ; Marques, A
Data: 2024
Identificador Persistente: http://hdl.handle.net/11110/3048
Origem: Politécnico do Cávado e do Ave
Assunto(s): PBAT; microcapsules; HDI; adhesives; environmental assessment; isocyanates
Thiswork introduces theencapsulationofhexamethylenediisocyanatederivatives(HDI,TriHDI, andPHDI)with thebiodegradablepolymerpoly(butyleneadipate-co-terephthalate) (PBAT) through a solvent evaporationmethod. Thesemicrocapsules(MCs)werethenemployedinadhesiveformulations for footwear.Moreover,MCs containingPHDIwereproduced ina closed vessel, demonstrating the potential for recovering and reusingorganicsolventsforthefirsttime.TheMCswereachieved withan isocyanatepayloadreachingupto68wt%, displayinga spherical shape, a core−shell structure, and thinwalls without holesorcracks.TheapplicationofMCsascross-linkingagentsfor adhesives was evaluated following industry standards. The adhesives’ strength surpassed theminimum requirement by a significantmargin.Creeptestsdemonstratedthat the formulationwithMCs exhibits superior thermostability. Furthermore, the formulationwithMCs-PHDIpresentedthebestresultsreportedtodateforthistypeofsystem,asnodisplacementwasobservedin thebondedsubstrates.EnvironmentalassessmentindicatesthatadhesiveswithMCshavehigherglobalwarmingpotential(+16.2%) andenergyconsumption(+10.8%)thanthestandardcommercialadhesives,butunderalternativerealisticscenarios, thedifferences canbe insignificant.Therefore, adhesive formulations incorporatingMCspromisetobeonparwithtraditional adhesivesystems regardingenvironmental impactswhileprovidingbenefitssuchasimprovedandsafehandlingof isocyanatesandexcellentbonding effectiveness.
