Insights into the thermo-mechanical properties of films cast from emulsion terpolymers

Emulsion polymerization is among the most used processes at the industrial level for the production of a wide range of polymers. The films cast from such emulsions are widely used in coatings industry and their thermo-mechanical properties are extremely important. In this work, n-butyl acrylate was copolymerized with different monomers (styrene, methyl methacrylate and acrylonitrile) in emulsion polymerization, using reaction conditions feasible to be applied at the industrial level. The films cast from the emulsions were characterized in terms of their chemical structure and the structure/thermo-mechanical properties relationships were studied in detail using different thermal analysis techniques. Both the thermal stability and the thermo-mechanical behaviour showed to be highly dependent on the type of monomers used during the emulsion polymerization. The films showed no melting temperature, indicating that the copolymers formed were amorphous. The elastic modulus and glass transition temperature showed to be dependent on the different percentages of the monomers used in the formulation and it was clearly shown that small changes on composition have strong impact on the mechanical and thermal properties of cast films. To the best of our knowledge, this work presents the first study towards the understanding of the properties of the films obtained from cast acrylic emulsions.