Functionalized GO/polysulfide rubber composites with excellent comprehensive properties based interfacial optimum design

Abstract

Polysulfide rubbers (PSR) have been widely used as high performance sealants to line or seal aircraft fuel tanks. In this research, liquid polysulfide oligomers-graphene oxide (LPO-GO) nanocomposite was prepared through the mild reaction between liquid polysulfide oligomers (LPO) and graphene oxide (GO) nanosheets, and was dispersed into PSR to obtain LPO-GO/PSR composites. Benefit from the grafting of polysulfide oligomer segments on the surface of GO, good dispersion of LPO-GO in PSR matrix was achieved. The mechanical properties of PSR composites were enhanced by LPO-GO. The elongation at break and tensile strength of the 0.5% LPO-GO/PSR composites were about 70% and 43% higher than that of neat PSR. The dynamic mechanical thermal analysis (DMTA) results showed that the storage modulus of PSR was increased by 206% when 0.5% of LPO-GO was added. The broadband dielectric spectroscopy (BDS) results indicated that LPO-GO was well dispersed in PSR and some phenomena of molecular chain movement in PSR matrix. Study of the reinforcing mechanism showed that a number of thiol groups and S–S bonds had been attached onto the surface of GO after being modified by LPO, which quietly promoted the dispersion of LPO-GO in PSR matrix and strengthened the interfacial interactions between LPO-GO with PSR.