Preparation of waterborne alkyd–acrylic nanoscale hybrid systems

GOIKOETXEA, MONIKA; MINARI, ROQUE J; BERISTAIN, ITXASO; PAULIS, MARÍA; BARANDIARAN, MARÍA J.; ASUA, JOSÉ M.

Il Ciocco - Lucca

Conferencia; IPCG Conference on Polymer Colloids; 2009

Intenational Polymer Colloids Group

In a scenario of increasing concern for sustainability and stricter environmental legislation coating industry has switch to water-based products like acrylic latexes. However, although acrylic latexes offer many advantages, they still lack of the advantages of alkyds. Therefore, the waterborne combination of alkyds and acrylics is expected to result in coatings that have better properties. The challenge is to compatibilize them. Waterborne acrylic-alkyd nanocomposites are expected to combine the positive properties of alkyd resins and acrylic polymers. It is believed that the best way of combining the positive properties of both systems could be achieved when a chemical linkage of the alkyd and acrylic polymer was obtained. In this way, miniemulsion polymerization allows the incorporation of hydrophobic components, like alkyd resins, into polymer particles due to mass transfer through the aqueous phase is avoided. Formulation and polymerization conditions affect the extent of the mentioned compatibilization. In addition, the amount and distribution of the acrylic homopolymer, the free resin and the grafted copolymer is an issue of concern in hybrid systems and determines the particle morphology which strongly influences the properties of the hybrid materials. In this work the kinetics of the miniemulsion polymerization used to synthesize these nanocomposites and the effect of the process variables on the polymer architecture (molecular weight, acrylic and resin degree of grafting) and particle morphology was investigated. It was found that resin hydrophobicity and the type of initiator strongly affected the microstructure of these materials.