Synthesis, characterization, and properties of silane-functionalized expandable graphite composites

In this study, synthesis and properties of green flame retardant of silane-functionalized expandable graphite (EG) composites were investigated. The coupling agent was used to improve the interface between the matrix and EG. Fourier transform infrared spectrophotometry and X-ray photoelectron spectroscopy were adopted to characterize the functionalized EG. It was affirmed that 3-aminopropyltriethoxsilane (APTS) has been grafted on EG. The modified EG composites improved thermal property, corresponding to functionalized EG. 29 Si-nuclear magnetic resonance and scanning electron microscopies were used to study the structure and the morphology property of the modified EG composites. It showed that flake graphite existed in the matrix. Energy dispersive X-ray analysis indicated that Si atoms appeared due to APTS grafted on EG. The expanded structures of graphite were formed after burning. The foamed layer demonstrated the mechanism of protection of EG. The results present poly(methylmethacrylate)/silane-modified EG(PMMA, poly(methylmethacrylate) composites that have excellent thermal stability and flame-retardant property compared to pure PMMA resin.