Processing and characterization of PMMA/PI composites reinforced with surface functionalized hexagonal boron nitride

Poly(methyl methacrylate) (PMMA) is acknowledged as a conventional polymer matrix because of its light weight, low friction, optical clarity, and environmental stability, with properties including UV resistance and moisture resistance. In the present study, PMMA/polyimide (PI)/hexagonal boron nitride (hBN) composites were processed by incorporating PI and hBN powder into the PMMA matrix. To augment the dispersion, the surfaces of hBN particles were functionalized with 3-aminopropyltriethoxysilane (3-APTS), which serves as a coupling agent. Two cases of composites were considered: one with as-received hBN and another one with silanized hBN. For validation of changes after silane treatment, X-ray diffraction, and Fourier transform infra-red were performed. The changes in morphology after surface treatment were analyzed through field-emission scanning electron microscope and high-resolution transmission electron microscope. The effects of hBN functionalization on the thermal properties of the composites were analyzed by thermo-gravimetric analysis. The tribological properties of the composites were studied by friction and wear tests and the morphology of the wear track was investigated using a surface profilometer and field-emission scanning electron microscope. The outcomes of these investigations indicated that the composite with silanized hBN exhibited superior tribological properties in comparison to the composites with as-received hBN.