Summary: | 碩士 === 中國文化大學 === 應用化學研究所 === 92 === Abstract
The reaction of respective toluene diisocyanate (TDI), 4,4-diphenylmethane (MDI) and isophorone diisocyanate (IPDI) with polyester and other additives to form the conformation of polyurethane (PU) ionomer coatings has been demonstrated by IR spectra. The experimental results show that both viscosities and average particle sizes of anionic-type polyurethane ionomer-type polyrethane ionomer coatings in aqueous solution appear to increase with increasing concentraction of TDI, MDI and IPDI, respectively. This is the result of increased free volume of polyurethane ionomer molecules resulting from increasing intermolecular interaction between PU ionomer molecules themselves and between PU ionomer molecule and water molecule. In aqueous solution, the surface tension of anionic-type PU ionomer is seen to increase with an increase of diisocyanate concentration, as a result of hydrophobics adsorbed at the surface becoming even more ordered.
Experimental results also indicate that the tensile strength of film made by anionic-type PU ionomer coatings appear to increase with increasing concentration of TDI, MDI and IPDI, respectively. This is because increased intermolecular interaction between PU ionomer molecles themselves may make the crosslinking capability of PU ionomer coatings molecule become stronger. Therefore, the tensile strength of the film made by anionic-type PU ionomer coatings increases.
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