Novel porous nanohybrid materials with unexpected mechanical and electrical performance by pyrolysis of carbon nanotube-filled benzoxazine thermosets

L Dumas,L Bonnaud,P Dubois

doi:10.1080/20550324.2016.1254927

Abstract

In this communication, we highlight the remarkable and unexpected mechanical and electrical properties of new porous nanohybrid materials as readily obtained by a two-step preparation procedure. Neat multi-wall carbon nanotube (CNT)-reinforced benzoxazine nanocomposites were first produced. At a CNT content of 5 wt%, pyrolysis of the nanocomposites allowed for recovering porous monolithic nanohybrid materials exhibiting outstanding mechanical resistance (elastic modulus of ca. 50 MPa) for an electrical conductivity as high as 30 S cm−1. Interestingly, long CNTs were found to build up an internal scaffold limiting the deformation of the foamed structure and preserving the geometric shape and dimensional integrity of the sample along the pyrolysis process. The concept of this novel approach paves the way for the production of a very promising choice of viable (nano)materials for use as domains as versatile as in energy storage, catalysis, or shielding applications.

Highlights

Due to their exceptional mechanical, thermal, and electrical properties, carbon nanotubes (CNTs) have received a major attention in the field of materials science
At a CNT content of 5 wt%, pyrolysis of the nanocomposites allowed for recovering porous monolithic nanohybrid materials exhibiting outstanding mechanical resistance for an electrical conductivity as high as 30 S cm−1
In a previous study,[15] we found that a diamino-based benzoxazine synthesized from phenol and p-phenylene diamine was able to establish strong supramolecular interactions with CNTs leading to a significant enhancement of the properties of the resulting nanocomposite network

Summary

Introduction

Due to their exceptional mechanical, thermal, and electrical properties, carbon nanotubes (CNTs) have received a major attention in the field of materials science. The thermal stability is in this case higher than 275 °C while the thermomechanical transition temperature Tα reaches 340 °C representing a shift of more than 80 °C when compared to the pristine matrix and nearly 30 °C higher than the nanocomposite containing 0.5 wt% CNTs. This result appears of high interest since an optimal CNT content of 0.5 wt% was previously observed for CNT contents lower than 1 wt%.16 In this low-CNT content range, the observed optimum was correlated to the coexistence of two mechanisms, namely interfacial constrains and free volume increase[17] but it seems that for a much higher CNT content, 5 wt% CNTs, the polymer chains must be still constrained and the network properties can be further reinforced.

Results

Conclusion