Abstract: The pyridyl-functionalized polystyrene/polybutadiene/polystyrene (SBS) membrane materials filled with various contents of lignin were prepared through solution casting. The effects of lignin contents on the performances of pynidyl-functionalized SBS (SBSVP) were studied by mechanical property testing and analysis of thermogravimetry analysis (TGA) and scanning electron microscopy (SEM). The tensile test results showed that the mechanical properties of SBSVP elastomer could be improved by the filling of lignin. The tensile strength and elongation for the SBSVP with 6% lignin were 12.6MPa and 840%. Compared with the unfilled SBSVP, the tensile strength and elongation at break of modified SBSVP increased for 32.63% and 3.83% respectively. The SEM analysis indicated that there was no remarkable interface between lignin and SBSVP, which showed an excellent interface compatibility. The TG analysis indicated that the SBSVP filled with lignin showed a higher weight loss than the pure SBSVP in the preliminary thermal degradation. In the middle and later periods of thermal degradation, the maximum decomposition speed of SBSVP filled with lignin was lower than that of pure SBSVP, and the corresponding maximum decomposition temperature was higher than that of pure SBSVP. In addition, the final weight retention of material filled with lignin was higher than that of pure SBSVP. This displayed the increase of thermal stability when SBSVP was filled by lignin.

Key words: thermoplastic elastomer, pyridyl-functionalized SBS, lignin, filling modification