Development of a novel flexible composite material

Abstract

The primary objective of this research work is to develop a thin and flexible composite material suitable for biomedical and electronic packing applications. A flexible composite of 0.2 mm thickness was developed using knitted polyester fiber interlock fabric as the reinforcement and polyurethane elastomer as the matrix. Details regarding composite fabrication and mechanical characterization are presented. The failure strain of this new flexible composite material is a s high as 85-320%, depending on the fiber architecture. Another objective of this study is to identify the effect of pre-stretching of the knitted fabric on the composite tensile properties. For this purpose different composite specimens were made by reinforcing polyurethane with knitted fabrics that were pre-stretched differently prior to composite fabrication. Both the stiffness and strength of composite improved in the direction of fabric pre-stretch and they deteriorated in the direction normal to pre-stretch. However, the failure strain followed the opposite trend. These trends are attributed to the changes in the failure mechanisms with the pre-stretched condition of the fabric.