Kinetics of curing of polyester adhesive based on liquefied wood

Proučevali smo kinetiko utrjevanja lepilnih mešanic iz melamin-urea-formaldehidnega lepila (MUF) in poliestrskega lepila na osnovi utekočinjenega lesa (PEST-UL). Pripravili smo lepilne mešanice z različnimi utežnimi deleži MUF in PEST-UL, katerih utrjevanje smo spreminjali z diferenčno dinamično kalorimetrijo (DSC). Vse lepilne mešanice smo segrevali s hitrostjo 10 °C min-1 v temperaturnem območju 25-400 °C. Ugotovili smo, da več kot je MUF lepilu dodanega PEST-UL, višja je temperatura prvega eksotermnega vrha. Z večanjem deleža PEST-UL v MUF lepilni mešanici, od razmerja MUF/PEST-UL = 90/10-50/50, se temperatura prvega eksotermnega vrha konstantno povečuje in sicer od 92,52-98,74 °Ctemperatura drugega eksotermnega vrha pa se glede na konstantno povečanje deleža variabilno spreminja in sicer od 292-299 °C. Z DSC metodo smo podrobneje proučili lepilno mešanico MUF/PEST-UL = 70/30 pri 3 različnih hitrostih segrevanja: 5, 10 in 20 °C min-1. Iz simulacije utrjevanja lepilne mešanice pri dinamičnih temperaturnih pogojih z uporabo MFK smo predvideli čase utrjevanja pri dinamičnih temperaturnih pogojih do določene stopnje utrjenosti lepilne mešanice.Thesis studies the curing kinetics of different adhesive mixtures from melamin-urea-formaldehyde adhesive (MUF) and polyester adhesive based on liquefied wood (PEST-UL). We prepared the adhesive mixtures with different proportions of MUF and PEST-UL mixture and noted the difference of differential dynamic calorimetry (DSC). All the adhesive mixtures were then heated with the speed of 10 °C min-1 within the temperature range of 25-400 °C. We found out that more PEST-UL adhesive added to the MUF adhesive increases the temperature of the first exothermic peak. By increasing the percentage of PEST-UL in MUF mixture the temperature of the first exothermic peak is constantly increasing with the ratio of 90/10-50/50 to the temperature of 92,52-98,74 °C, while the temperature of the second exothermic peak considering the constant increase of the proportion changes variably from 292-299 °C. Research also focuses on studying the adhesive mixture MUF/PEST-UL = 70/30 with the DSC method by different heating rate: 5, 10 and 20 °C min-1. By simulating the curing of the adhesive mixture in dynamic temperature conditions using MFK, the curing times at dynamic temperature conditions is attainted until certain degree of cure of adhesive mixture