Enhancing Elastomeric Performance and Application Window for Thermoplastic Polyurethanes (TPU) By Incorporation of Carbon Nanotubes (CNTs)

Among the most versatile thermoplastic elastomers are thermoplastic polyurethanes (TPU). TPUs are block copolymers that are made by combination of two types of segments that differ in stiffness. While soft segments provide the flexibility, hard segments provide the strength. Hard segments self-assemblies which are formed due to hydrogen bonding can act as physical crosslinks in the soft segment matrix and make TPU one of the high performance thermoplastic elastomers. TPU applications are limited at high temperatures due to the weakening of hydrogen bonding as well as softening of the hard domains. In this study, we have incorporated carbon nanotubes (CNTs) in TPU in order to reinforce them and compensate for the hard segments weakening at higher temperatures. We have used a sustainable and environmental friendly method to prepare TPU/CNT nanocomposites and showed that with effective dispersion of small fractions (as low as 0.3wt %) of nanofillers in TPU matrix, remarkable improvement in TPU performance at high temperatures can be obtained. The results show that by effective incorporation of CNTs in the TPU matrix, the rubbery plateau was extended, modulus at high temperature enhanced and creep and nonreversible deformation decreased.

Keywords: Thermoplastic elastomer, polyurethane, Nanocomposites, carbon nanotubes (CNT)

 

Acknowledgment

Authors acknowledge Parker- Hannifin Corporation for the financial support of this project. Special thanks to Val Comes and Glenn Craig for many useful discussions and suggestions.