Resinas alquídicas base água emulsionadas por inversão de fase

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

2011

RESUMO

This work reports the use of emulsion phase inversion technique to prepare waterbased alkyd resins, eliminating the use of organic solvents for dilution of this type of polymer, largely used in paint manufacture. First, alkyd polymers were synthesized by alcoholysis of vegetable oils and polyols in the presence of catalysts and subsequent esterification, condensation reaction of polyol and polyacid forming water as a byproduct. Among the various tests for polymers characterization, molecular weight by gel permeation chromatography-GPC, hydroxyl content and acid number were measured. Emulsions were prepared from polymers by the phase inversion method. In this process, water-in-oil emulsion (W/O) invert to an oil-in-water (O/W) after multiple water-inoil- in-water emulsion formation (w/O/W). ANOVA statistical technique was used to prepare a 23 full factorial with center point and duplicates to evaluate the best emulsification condition of alkyd polymer. The variables studied were: the emulsifier content, ratio of nonionic and anionic emulsifier and neutralization of the resin or not. A second design was prepared employing a new emulsification process to optimize the variables initially studied. The emulsions particle sizes were measured by light scattering and analytical centrifugation. We investigated the behavior over time through natural stability, for a period of 6 months, and correlated with the accelerated stability measured by analytical centrifugation. The stable long oil alkyd water-based resin obtained by replacing the step of dilution in organic solvent, process traditionally used in coatings industries, by the process of emulsification in water has an important role at the development of new products and technologies. Eliminating the step of decreasing resin viscosity with a large amount of organic solvent meets the more restrictive legislation on the use of volatile organic compounds, avoiding the presence of these compounds at the product.

ASSUNTO(S)

polimeros : resinas polimeros : caracterizacao polimeros : sintese

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