Interfacial Mixing of Urethane Foam Chemicals

The Use of FT-IR and Dynamic SAXS to Provide an Improved Understanding of the Matrix Formation and Viscosity Build of Flexible Polyurethane Foams

“…This is in part due to fact that the technology is based in part on 1500-2000 equivalent weight polyols which have high levels of ethylene oxide capping. The high levels of capping are known to increase reagent compatibility and improve the solubility of the in situ generated ureas [23,24]. Formulations can also be complicated by high levels of catalyst and the use of crosslinkers such as diethanolamine (DEOA) [2,11].…”

The morphology of rigid polyurethane foam matrix and its evolution with time during foaming – New insight by cryogenic scanning electron microscopy

“…Nonetheless, Grünbauer et al mentioned in a book chapter dedicated to rigid polyurethane foams that some doubts still subsisted whether nucleation could really occur by CO2 formed (possibly at the polyol/PMDI interface) from the H2O-PMDI reaction which is also known to occur during the early stage of the foam rise process [13]. As an example, Hager et al dynamically monitored the interfacial mixing process of various systems by video microscopy techniques when two liquid boundaries were put into contact and reported the formation and growth of gas bubbles in the polyol phase when toluene diisocyanate (TDI) was contacted with polyol containing 4% water, with or without 0.2% bis (2-dimethylaminoethyl) ether as catalyst [25]. In our study, cryo-SEM images seem to demonstrate that nucleation of bubbles does not occur at the interface between polyol and PMDI.…”