Optimization of molecular structure of polythiophene-graft-PMMA for effective compatibilization of SAN/MWCNT composite with superior mechanical properties

A new compatibilizer, P3HT-g-PMMA with controlled graft density and degree of polymerization of PMMA graft, has been synthesized for preparation of poly(styrene-co-acrylonitrile) (SAN)/multi-walled carbon nanotube (MWCNT) composites with superior mechanical properties. Fluorescence emission and Raman spectra reveal that the pi-pi interaction between polythiophene backbone of the compatibilizer and the surface of MWCNT is more effective as the graft density of PMMA in the compatibilizer is decreased while the degree of polymerization of PMMA is increased. Since FE-SEM observation also shows that the use of compatibilizer with higher degree of polymerization of PMMA graft yields well-dispersed MWCNTs in composites, it is concluded that the compatibilizer with lower graft density and higher degree of polymerization of PMMA graft is the most effective for reinforcing SAN with MWCNT.