Understanding the effect of nanokaolins on the physical and mechanical properties of nylon based composites

Kaolin minerals are increasingly being used as “Performance Minerals’ in polymer composites due to the promising benefits that they provide in terms of mechanical performance. Due to the downsides of the current state of the art, glass fiber reinforced plastics, kaolin minerals serve as a potential substitute to glass fibers. This thesis investigates the use of different kaolin formulations in a nylon 6 and a nylon 66 polymer matrix and analyzes the potential benefits on the mechanical properties of the composites. The minerals themselves vary in terms of surface treatment, particle size and aspect ratio. The composites are produced using a lab scale twin screw micro-extruder and injection molding machine. Mechanical tests, including tensile, flexural and impact, are conducted on the composites and the results are analyzed. In addition, XRD and DSC characterizations are performed to better understand the effect of the kaolins on the crystallization behavior of the nylons and investigate potential synergistic effects between kaolins and nylons. SEM imaging is also performed to better understand the fracture surfaces and the distribution of the mineral within the polymer matrix. Results from this study have shown that smaller particle sizes lead to a better tensile and flexural performance while higher aspect ratios lead to stiffer composites. Due to the nano scale particle size of the kaolin minerals, there is some agglomeration when the composites are compared in the SEM images. The mechanical performance demonstrated by the kaolin incorporated composites prove that kaolins can replace glass fibers while providing additional benefits such as better surface finish.M.S