Preparation And Properties Of Carbon Nanotube Grafted Epoxy Resin Curing Agent

In this paper,the SBS covalent bond grafting method was used to modify and surface functionalize multi-walled carbon nanotubes to improve its dispersity in the epoxy resin matrix and enhance the interfacial bonding strength.Firstly,modified multi-walled carbon nanotubes(SBS-g-MWNTs)were obtained by hydroxylation,amination and then amidation reaction with maleic anhydride grafted SBS(MAH-g-SBS),and the grafting rate reached 38wt%.In order to characterize and analyze the chemical structure of the products in each reaction stage,a series of methods were carried out,such as Fourier transform infrared spectroscopy(FTIR),thermal gravimetric analysis(TGA),X-ray photoelectron spectroscopy(XPS),scanning electron microscope(SEM),and transmission electron microscope(TEM).By mixing functionalized multi-walled carbon nanotubes(SBS-g-MWNTs)with an anhydride-based curing agent of epoxy resin(EP),we could prepare a carbon nanotube grafted epoxy resin curing agent.The composites were prepared by the stepwise curing method,and the mechanical properties and thermal properties of the composites were characterized.The test results showed that with the increase of SBS-g-MWNTs content,the tensile properties,flexural properties and impact properties were first increased and then decreased,which the maximum value with 0.75wt%content,and the tensile strength and impact strength were increased by 99.66%and 182.70%,respectively.The causes for the changes of mechanical properties were analyzed by dynamic mechanical analysis(DMA)and thermogravimetric analysis(TGA),the results showed that the glass transition temperature of the composites was determined to be 173? with 0.75wt%SBS-g-MWNTs content.The fracture surface of the composites were characterized by scanning electron microscopy(SEM).which showed a good bonding interface between SBS-g-MWNTs and epoxy resin,therefore,the epoxy resin could be better enhanced and toughened.