Improving impact, tensile and thermal properties of thermoset unsaturated polyester via mixing with thermoset vinyl ester and methyl methacrylate

The brittleness of thermoset unsaturated polyester (UP) limits its usefulness in many applications. Use of appropriate additives may improve the toughness of this material. The aim of this present study is to characterize the mechanical and thermal properties of the toughened UP and to relate these properties to the fracture surface morphology of the UP before and after adding various loadings of thermoset vinyl ester (VE) with 10% methyl methacrylate (MMA). VE loadings chosen were 10, 20, 30, and 40 wt%. UP mixed with 30%VE and 10%MMA displayed the best performance with a maximum impact strength of 314 kJ/m(2), a 17.6% increase compared to that of neat UP. This sample also had the highest tensile strength of 64 MPa (an increase of 45.5%), higher elongation at the break of 13% (an increase of 27%), and higher thermal resistance. Addition of 30% VE and 10% MMA significantly improves a range of important properties of UP. This blend has a high potential to be used in UP resin applications where toughness is required.