Enhancing Mechanical and Thermal Properties of Polyurethane Rubber Reinforced with Polyethylene Glycol-g-Graphene Oxide

Abstract

This paper attempted to achieve the purpose of increasing the tensile strength and toughness of polyurethane rubber (PUR) simultaneously by introducing polyethylene glycol (PEG) onto the surface of graphene oxide (GO) to introduce hydrogen bond interactions into the PUR-GO system. GO was grafted with PEG and added to PUR by mechanical blending. The polyethylene glycol-g-graphene oxide (MGO) was characterized by infrared spectroscopy, Raman spectroscopy, X-ray diffraction, and thermogravimetric analysis. The PUR/MGO composites were tested by tensile testing machine, thermogravimetric analysis, dynamic thermal analysis, and scanning electron microscopy. The results demonstrated that PEG was successfully grafted onto the surface of GO and the grafting rate was about 37%. The grated PEG did not affect the crystalline structure of GO. The addition of MGO could improve the thermal stability of PUR vulcanizate. After the addition of GO, the glass transition temperature (Tg) of vulcanizate was shifted to higher temperature. However, the Tg of vulcanizate reinforced by MGO was shifted to lower temperature. The strength and toughness of vulcanizate were significantly improved by adding MGO. The reason was that the hydrogen bond interactions between MGO and PUR were destroyed and the hidden length was released during the strain process. A lot of energy was consumed, and thus the strength and toughness of PUR vulcanizate were improved.