Preparation and electrodeposition properties of trimethylolpropane–toluene diisocyanate–dimethylaminoethanol/2‐ethylhexanol resins

Abstract

SYNOPSIS2,4-Toluene diisocyanate (TDI ) was partially blocked with equimolar mixtures of dimethylaminoethanol (DMAE) and 2-ethylhexanol(ZEH) of different ratios to form the DMAE/ 2EH half-blocked TDIs, which were subsequently reacted with 1 /3 mol trimethylolpropane ( TMP ) to yield the trimethylolpropane-toluene diisocyanate-dimethylaminoethanol/ 2-ethylhexanol ( TMP-TDI-DMAE/ 2EH ) resins having various content of tertiary amine groups. These resins were neutralized with acetic acid and then dispersed in deionized water, resulting in the milky emulsions used for cationic electrodeposition. Some electrodeposition properties, such as deposition yield, conductivity, rupture voltage, and throwing power, of the resins were investigated. In addition, one of the obtained resins (added as a crosslinker) and an amine-epoxy adduct were codispersed in deionized water, and the nature of electrodeposition of the two-component emulsion is discussed.

Synthesis and assessment of novel anticorrosive polyurethane coatings containing an amine-functionalized nanoclay additive prepared by the cathodic electrophoretic deposition method

“…Particle size of the dispersed components in electrodeposition bath can drastically inuence on characteristics of the system such as stability and shelf life of dispersion, the kinetic of lm growth, electrophoretic velocity of charged particles and dry lm thickness. 40,41 Therefore, the particle sizes of aqueous dispersion of protonated HPU, BIC and a mixture composed of the equivalent amounts of HPU and BIC at solid content of 10 wt% were measured (Fig. 3).…”