Aqueous polyurethane dispersions (PUD) has been investigated by many researchers for a long time. However, relatively little systematic work has been reported, in detail, on the effect of structure of the diisocyanate on the properties of polyurethane...
Aqueous polyurethane dispersions (PUD) has been investigated by many researchers for a long time. However, relatively little systematic work has been reported, in detail, on the effect of structure of the diisocyanate on the properties of polyurethane. This work describes the properties of polyurethane in relation to the variation of diisocyanate type and contents. Aqueous polyurethane dispersions (PUD) were prepared from the poly(tetramethylene ether) glycol (PTMG), toluene 2,4-diisocyanate (TDI), isophorone diisocyanate (IPDI), dimethyol propionic acid (DMPA), and triethylamine (TEA). Differential scanning calorimetry (DSC), FT-IR, GPC, universal testing machine (UTM), and particle analyzer were utilized to characterize the physical and mechanical properties of PUD according to diisocyanate type and contents. As the content of IPDI in PUD increased, the particle size decreased. The glass transition temperatures (Tg) of PUT were shifted to a lower temperature as IPDI conent increased. When [NCO]/[OH] mole ratio was 1.2, the adhesion force of PUD shown the best result at [TDI]/[IPDI] mole ratio of 50/50. And, at [NCO]/[OH] mole ratio of 1.2, the adhesion force of PUD was the best when [TDIl/[IPDI] mole ratio was 75/25.