Study On Synthesis And Properties Of Aliphatic Polyester Aqueous Polyurethane Dispersions

In this paper, a series of aqueous polyurethane dispersions were synthesized from the polyester polyol, isophorone diisocyanate (IPDI) and dimethylol propionic acid (DMPA) by neutralization emulsification method. It consists of two parts: (1) the study of synthesis and properties of anionic aqueous-based polyurethane; (2) the study of synthesis and properties of anionic aqueous-based polyurethane modified with hydroxyl silicon oil, aziridinyl external curing agent and light stabilizer.In the study of synthesis and properties of anionic aqueous-based polyurethane, the effects of the molar ratio of NCO/OH groups, amount of dimethylol propionic acid (DMPA), adding material sequence, the method of neutralization, degree of neutralization, temperature of chain extension and amount of acetone on the chemical structure and the properties were discussed. The average particle size was measured by 90 Plus Paritcle Analyzer. (BROOKHAVEN INSTRUMENTS CORPORATION) The chemical structure of films was performed with VECTOR-22FTIR. Stability of electrolyte was measured by 10% sodium chloride solution titrimetric analysis. Ratio of absorbing water, mechanical properties and bonding strength of films were measure. It was shown that the average particle size of the anionic aqueous-based polyurethane dispersions increased with an increasing molar ratio of NCO/OH groups, decreasing DMPA content, increasing degree of neutralization or decreasing amount of acetone. Compared with two methods of neutralization, the method I is better. Fourier transform infrared (FTIR) analysis showed anionic aqueous-based polyurethane.In the study of modification of anionic aqueous-based polyurethane, the effects of amount of hydroxyl silicon oil, amount of aziridinyl external curing agent and light stabilizer on the chemical structure and the properties have been investigated. The results showed that tensile strength of films increased and elongation at break of films declined with an increasing amount of hydroxyl silicon oil. By analysis of FTIR, the aziridinyl external curing agent may be a kind of ester compound. In this research, we expatiated the action theory of the light stabilizer. It was shown that the light stabilizer used in the experiment was...