Functionalized multiwall carbon nanotubes to enhance dispersion in castor oil-based polyurethane nanocomposites

Abstract

In recent years, lots of stress has been laid on impregnating polymer nanocomposites with carbon nanotubes (CNTs) to impart multifunctional properties. To yield the maximum benefits, it is imperative that proper dispersal of CNTs and a resilient interfacial bonding between polymer and CNTs is achieved. Chemical functionalization is widely used on the surface of CNTs to prevent their agglomeration and improving interfacial adhesion between polymer and the graphitic surface of CNTs. The study explores the potential of carboxylic acid functionalized CNTs for reinforcement in polyurethane nanocomposites. Techniques like Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD), and thermogravimetric analysis (TGA) was used to assess the functionalization on the surface of CNTs. The FTIR studied confirmed the attachment of carboxyl groups to the MWCNTs after treating them with the acidic solution. The TEM results confirmed reduced agglomeration and size of functionalized CWNTs. The functionalized MCNTs were reinforced into castor oil based polyurethanes to synthesize polyurethanes with improved dispersion.

Keywords:

• Chemical functionalization
• carbon nanotubes
• dispersion
• polymer matrix
• FTIR/TEM

Acknowledgments

The authors are highly thankful to UGC-CSIR for project sanction no: 22(0798)/19/EMR-III dated 24/07/19, DST grant vide SEED/TIASN/008/2018 dated 6/06/2018 to one of the authors and Dr. S.S. Bhatnagar University Institute of Chemical Engineering & Technology, Panjab University, Chandigarh for procurement of chemical and instruments. Also grateful to Institute Instrumentation Centre IIC-IIT Roorkee for testing facilities.

Scope for future

To use the distinctive and superior properties of CNTs they need to be functionalized. The good dispersion of CNTs will lead to enhance the properties of the base material, even if used in smaller quantities. They will lead to improve the mechanical and electrical properties and can be studied further.