Characterization of novel composites from polybenzoxazine and granite powder

The potential of using granite dust as reinforcement into polybenzoxazine matrix was investigated. In this article, novel
granite powder waste-reinforced bisphenol-A aniline-based benzoxazine composites were prepared using solution
blending technique by varying the content of granite powder from 10 to 40 wt%. The efect of the granite powder
content on the thermal, structural, dimensional, and morphological properties of granite powder/polybenzoxazine
composites have been investigated. Thermogravimetric analysis (TGA) was performed on the composite samples. Char
yield of the composites increased from 44.55 to 67.70% for increasing fller content from 10 to 40wt%, whereas 22%
for pure polybenzoxazine. The maximum weight loss temperatures of the composites were analyzed from derivative of thermogravimetric analysis (DTG). Limiting oxygen index (LOI) values also increased as granite powder content increased.
Structural properties of benzoxazine, polybenzoxazine, and composites were observed with Fourier-transform infrared
spectroscopy (FTIR). Dimensional stability of the composites was investigated through the water absorption test up to
30 days. The composites exhibited zero percent water absorption. Micro-hardness of the composites increased from
17.45 to 78.66% for increasing fller content from 10–40 wt% when compared with pristine polybenzoxazine. The mor�phological analysis using scanning electron microscopy (SEM) showed the distribution of fller, aggregate formation,
compatibility between polybenzoxazine and granite powder. Overall, the importance of using granite powder waste as
reinforcement in polybenzoxazine composites revealed from results of the structural, dimensional, and morphological
analysis along with the improvement in thermal properties and micro-hardness