Mechanical properties and features of fractured surface micrographs of bamboo particle reinforced unsaturated polyester composites

Bamboo particles reinforced unsaturated polyester (UPE) composites were prepared by compression molding and their mechanical properties were evaluated. The effect of bamboo particle size on the mechanical properties of composites, and the quantitative relationship between the features of fractured surface micrographs of composites and their mechanical properties were investigated. The interfacial adhesion of bamboo/UPE composites was characterized by scanning electronic microscope (SEM). The features of SEM graphs were quantitatively extracted by Fourier features of local binary pattern histograms. The results showed that the tensile strength, flexural strength and flexural modulus of composites reinforced with 30-40 mesh bamboo particles increased by 32.9%, 34.4%, and 25.4% compared with that of 20-30 mesh bamboo particles, respectively. The tensile strength, flexural strength and flexural modulus of 100-120 mesh bamboo particles composites decreased by 10.6%, 20.8%, and 12.9% respectively compared with that of 30-40 mesh bamboo particles. While the tensile strength and flexural strength of 200 mesh bamboo particle reinforced composites increased by 11.7% and 18.3% compared with that of 100-120 mesh, respectively. The visual features of SEM graphs from composites fractured surface indicated that there were obvious differences among the SEM graphs of composites with different bamboo particle sizes. The composites with similar mechanical properties have similar texture features extracted from their SEM graphs. Our research proposes a novel approach for characterizing the relationship between the micro-morphology of composites and their mechanical properties by extracting the micrograph features from the fractured surfaces of composites.