Waterborne acrylic-melamine latexes with controlled film microstructure

RONCO, LUDMILA I.; GUGLIOTTA, LUIS M.; CÓRDOBA, CARLOS A.; MINARI, ROQUE J.; PASSEGGI, MARIO C. G.

PROGRESS IN ORGANIC COATINGS

ELSEVIER SCIENCE SA

Lugar: Amsterdam; Año: 2019 vol. 136 p. 1052391 - 1052398

0300-9440

Crosslinkable latexes aim to improve the physical properties ofcoalesced latex films, over levels attainable with thermoplastic latexes, whichlack thermal, mechanical and solvent resistance. This work investigated the synthesisby miniemulsion polymerization of waterborne acrylic-melamine nanocompositeswith the aim of obtaining high solid-content latexes (50%) with controlledcrosslinkable capability. Changes in both the acrylic polymer microstructure(i.e., content of hydroxyl groups and molecular weight) and the amount ofmelamine (a commercial iso-butylated melamine-formaldehyde resin) showed asignificant influence on the crosslinking degree, and consequently on the finalproperties of cured films at high temperature. It was observed that reducing molecularweight of acrylic polymer allowed a good chain inter-diffusion during thecourse of film preparation, increasing crosslinking occurrence. Also, thecontent of hydroxyl groups and melamine could promote the enhancement of final filmproperties.