ABSTRACT
Thermoplastic polyurethane (TPU) has excellent characteristics of light weight, corrosion resistance, flexible formula, and adjustable performance, and it is suitable as a road asphalt modifier. To explore the chemical interaction between the TPU modifier and asphalt, FTIR was employed to measure the infrared spectra of polyester -type and polyether-type TPU modifiers and their modified asphalt. The chemical interaction between the TPU modifier and asphalt binder is speculated through the analysis of absorption peak characteristics. The modification and strengthening mechanism of the TPU modifier are revealed. The results show that the TPU-modified asphalt emerges some new absorption peaks compared with the base asphalt. Both polyester and polyether TPU react with carboxylic acid and other active functional groups in the base asphalt to generate new compounds. The reaction equation of isocyanate with phenol and carboxylic acid and the internal crosslinking reaction equation of TPU-modified asphalt were deduced.
