Basic Knowledge of Wide-angle X-ray Diffraction

Abstract

Though the inherent elasticity of rubber materials is derived from the amorphous polymer chains, crystals are also an important factor in understanding the physical properties of rubber. For example, in natural rubber, butadiene rubber, chloroprene rubber, and some others, crystallization occurs under high elongation, which is thought to exert a self-reinforcing effect. Also the hard segments of urethane rubbers are sometimes crystalline. Dynamic change of such crystal structures has a significant effect on the physical properties of rubber, and wide angle X-ray diffraction (WAXD) is a powerful tool for analyzing such dynamic structural changes. In this paper, we aim to explain the basic principles of WAXD in as simple words as possible for readers who are not familiar with WAXD measurements.