Synthesis of 3-in-1 type co-coreshell reinforcer - toughener - compatibilizer for rigid matrices via grafting approach

Abstract

In this project, synthesis and characterization of 3-in-1 type co-coreshell structured reinforcer-toughener-compatibilizer for rigid polymer matrices were conducted to provide enhanced mechanical properties and thermal stability to polystyrene by obtaining optimal dispersion of P(AN-co-VAc) nanospheres in the matrix. Crystalline poly(ethylene oxide) blocks (PEO) were synthetically grafted onto maleic anhydride grafted polystyrene-b-poly(ethylene/butylene)-b-polystyrene (SEBS-g- MA). The grafting efficiency was investigated by 1H NMR and FTIR spectroscopic techniques and the thermal characterizations were conducted by TGA and DSC to analyse particularly the thermal stability and phase behaviors of graft copolymer. High shear mixing technique was used to provide better dispersion of P(AN-co-VAc) nanospheres in the graft copolymers having suitable polar sides to surround the nanospheres by hydrogen bond and dipole-dipole interactions. Effect of expanded P(AN-co-VAc) on dispersion quality was particularly discussed. In situ synthesis of polystyrene nanocomposites in the presence of obtained co-coreshell structures were carried out and resultant nanocomposites were inspected in terms of morphology, mechanical and impact strength as well as thermal properties. It has been found that , compared to neat PS, PS / SEBS-g-PEO 1% XP(ANco- VAc) exhibited not only the highest toughness but also increased thermal stability and flame retardancy . It is confirmed by this study that, covalently bonded bridges between each layers via grafting inhibited the extensive phase separation which then resulting in both stable co-coreshell structures and extra simultaneous benefits particularly on reinforcing, toughening and compatibilizing issues of rigid polymers.