| 초록 |
In the coating industries, there is strong commercial needs to optimize the perfoermance of water borne systems to replace the solvent based coatings as pressures to reduce VOCs increase. Poly(ethylene-co-acrylic acid)(PEA) ionomer dispersions are known to offer high perfoermance in terms of their combination of chemical resistance, optical clarity and adhesion. However, films of PEA ionomer dispersions are so brittle. To improve the mechanical properties of film properties, we prepared blends of water borne polyurethane(PU) with elastomeric properties and PEA ionomer. PEA ionomer dispersions of the various degree of neutralizations were prepared and then the remaining carboxylic acid in the blends were crosslinked with aziridine. We studied also effects of organoclay, Closite 30B, on the blends. The properties of PEA ionomer dispersion/water borne PU blends after drying were investigated using a DSC, DMA, tensile testing machine, XRD and TEM. Only one glass tansition temperature was observed in the of PEA ionomer dispersion/water borne PU blend films around at -70℃. With increasing the degree of neutralization, the rubbery plateau region was extended to higher temperatures. From XRD and TEM obserbation, nanocomposites of the blends showed fine dispersion of organoclay. |
