Authors Pavlova, E. ; Voit, B. ; Duskova-Smrchova, M. ; Dusek, K.
Title Novel hyperbranched polymers for polyurethane coatings: Their preparation and crosslinking with polyisocyanates
Date 14.12.2004
Number 12807
Abstract Novel hyperbranched polyesters (HBP) bearing hydroxyl groups, based on 4,4-bis-(4’-hydroxyphenyl)pentatonic acid were synthesized by melt polycondensation at 230 °C under vacuum. The number-average molecular weights of products ranged between 2,000 and 3,000 g/mol. The average functionality was 9-11 hydroxyl groups per molecule. High-solids polyurethane coatings were prepared by cross-linking with trimer of hexamethylene diisocyanate. Model kinetic studies were performed with 4-ethylphenol. The half-life of reaction of HBP with triisocyanate (about 480 min at 25 °C) was approximately four times lower than that for 4-ethylphenol due to steric hindrance in the HBP structure. The glass transition temperature of cured coatings was about 120 °C. The surfaces of films were smooth and relatively polar. HBP proved to be suitable precursor for elevated temperature cured, two-component high-solids polyurethane coatings.<br /><br />New Developments in Coatings Technology<br />The 228th ACS National Meeting, in Philadelphia, PA, August 22-26, 2004
Publisher Polymer Preprints
Citation Polymer Preprints 45 (2004) 217-218

Back to list