Controllable synthesis of network polyacrylate from hyperbranched polyesters and their effect to bond strength of asphalt

In this work, a couple of network polyacrylates (NPA-HBPE-G2/G3/G4) were synthesized from the different generation hyperbranched polyester (HBPE) and acrylate monomers, and used to enhance the interfacial adhesion of asphalt with inorganic minerals. The molecular structure and respective performance of NPA-HBPE were characterized by FTIR, 1 H NMR, TGA and fluorescence microscopy. The results showed that NPA-HBPE had a great number of polar functional groups on the branched chains, and processed superior thermal stability, good ductility and excellent compatibility with the asphalt. More importantly, the NPA-HBPE demonstrated a significant effect on improving the bond strength of asphalts with cement mortar block. As the volume addition of NPA-HBPE-G4 was 10 wt%, the maximum bond strength of modified asphalts reached 1.23 MPa while that the base asphalt was only 0.48 MPa. Furthermore, the adhesive force of NPA-HBPE-G4 modified asphalts was high to 333 nN, and fairly better than that of base asphalts (71 nN). This study would provide a simple and efficient approach to improve the bond strength of asphalt, and would have enormous potential in the engineering field.