How does the isophthalic unsaturated polyester affect the dielectric properties, the glass transition, and the ductility of bitumen?

Abstract

Bitumen with 50/70 penetration was prepared and modified by doping with the unsaturated polyester resin based on isophthalic acid at 5% by weight (w/w%).The structural, mechanical, and thermal properties of bitumen and bitumen modified with unsaturated polyester resin %5 (UPR) were determined. The dielectric properties of bitumen and modified bitumen were investigated in the frequency and temperature ranges of 0.1-106 Hz and (-)40 degrees C- 40 degrees C, respectively. Polarization mechanisms, glass-transition temperature, and ductility of all samples were determined and compared to each other. The glass transition temperature of the modified bitumen shifts toward low temperatures in comparison to the bitumen. So, it can be suggested that the use of modified bitumen is very attractive in regions where the temperature differences are high. Also, the dielectric analysis method is an innovative alternative to determining modified bitumen's low-temperature performance. It was found that the modification with UPR provide strength and flexibility to asphalt.