Preparation and Characterization of Structurally Graded Poly(urethane urea) Elastomers

Abstract

Poly(urethane urea) elastomers with graded structure in the thickness direction were prepared using gradient temperature molding. Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and differential scanning calorimetry (DSC) were used to characterize the gradual change of structures within the elastomers. The degree of microphase separation in prepared samples would increase gradually with the increase of the curing temperature. Moreover, the interfaces between hard and soft segments also exhibit gradual changing trend, becoming more significant along the same direction. Effect of chain extender content and magnitude of temperature gradient on structure gradient was investigated. Mechanical properties of graded poly(urethane urea) elastomers were also studied.

Keywords:

• Functionally graded materials
• Microphase separation
• Poly(urethane urea)
• Temperature gradient