Evaluation of hard segments content on dispersion of graphene in polyurethane nanocomposites by XRD method

Polyurethanes are very versatile polymer materials and their properties can be modified by varying the polyurethane microstructure and by dispersing inorganic fillers inpolyurethane matrix [1]. Thermoplastic polyurethanes (TPUs) are linear block copolymers consisting of alternating hard andsoft segments. The purpose of this research is to investigate the effect of expanded graphite (EG) loading on the microstructure development of the thermoplastic polyurethanes (TPU) based nanocomposites prepared by in-situ polymerization[2]. Thermoplastic poly urethane is, basically a segmented multiblockcopolymer whose chain structure is alternating flexible component or macrodiol, called soft segment, and a stiffcomponent from di-isosyanate and a chain extender, called hard segment [3,4]. These two segments are thermodynamically immiscible, leading to a phase separation and the formation of rigid and flexible domains. In this study, the effect of nano graphene and different hard segment on configuration of thermoplastic poly urethane (TPU) has been investigated