Investigation of impact behavior of various silica-reinforced polymeric matrix nanocomposites

Three polymeric based nanocomposites with a silica reinforced particle and coupling agent were prepared using sol–gel methods. The hybrid specimens with silica content from 10 to 50 wt% were used to investigate their mechanical properties, as well as their morphological structure and matrix characteristics under impact loading. Three different polymer matrixes, polyacrylate (PA), polyimide (PI) and polypropylene (PP), were selected as the matrix materials for silica reinforced composites. The effects of the silica content on the structure and the interaction between individual constituents was identified within an impact energy range of 0.5–30 J. It was found that all silica filled composites had a reduced interfacial crack area when specimens were subjected to low energy impact. The PA-based hybrid filled with 30 wt% silica was found to have the best structural stiffness among the specimens tested. The maximum stress intensity factor of the PA-based hybrid was enhanced significantly as compared to unfilled specimens (PPA). The steady state fracture toughness (KIS) of the PA-based hybrid was approximately 45% higher than that of PPA. The result of morphological structure analysis using a scanning electron microscope revealed that a strong correlation was established between the fracture toughness and the percolation network of the particle agglomeration.