Synthesis and Physicochemical Behaviour of Polyurethane-Multiwalled Carbon Nanotubes Nanocomposites Based on Renewable Castor Oil Polyols

Alaa Ali,Kamal Yusoh,S F Hasany

doi:10.1155/2014/564384

Abstract

Polyurethanes (PUs) are high performance materials, with vast industrial and engineering applications. In this research, effects of Multiwalled Carbon Nanotubes (MWCNTs) on physicochemical properties of Castor Oil based Polyurethanes (COPUs) were studied. MWCNTs were added in different weight percentages (0% to 1% wt) in a castor oil based polyurethane (COPUs-MWCNTs) nanocomposites. The composition, structure, and morphology of polyurethanes were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), field emission scanning electron microscopy (FESEM), and element detection by energy dispersive spectroscopy (EDX) analysis, respectively. Thermal stability was studied by thermogravimetric analysis (TGA). Barrier properties and surface area studies were investigated by nitrogen permeability machine and BET technique. Mechanical properties were calculated by tensile universal testing machine. Results showed well dispersed MWCNTs in polyurethane matrix at different weight percentages. The best results were obtained with 0.3 wt% of MWCNTs in the composite. Surface area studies revealed presence of very few pores which is in a good agreement with barrier permeability, reduced up to ~68% in 1 wt% and ~70% in 0.5 wt% of MWCNTs in polymer matrix, with respect to pure COPUs samples.

Highlights

IntroductionPolyurethanes are versatile polymeric materials with extensive demand due to exceptional physical properties (e.g., high flexibility, high tensile strength, tear and abrasion resistance, solvent resistance, etc.) and high versatility in chemical structures (discussed by Lu and Macosko [1]; reported by Cao et al [2]; studied by Oprea [3]; discussed by Akintayo et al [4])
Polyurethanes are versatile polymeric materials with extensive demand due to exceptional physical properties and high versatility in chemical structures
Fourier transform infrared spectroscopy (FTIR) spectrum indicates a peak at ranges from 1715 to 1725 cm−1, which refers to carbonyl hydrogen bonding present in nanocomposites, with different intensities; the Castor Oil based Polyurethanes (COPUs) peak is much sharper and intense while in the case of both of the COPU nanocomposites the peak became broad with lower intensity, predicting a reduction in carbonyl hydrogen bonding due to purified Multiwalled Carbon Nanotubes (MWCNTs) intercalation in COPU matrix

Summary

Introduction

Polyurethanes are versatile polymeric materials with extensive demand due to exceptional physical properties (e.g., high flexibility, high tensile strength, tear and abrasion resistance, solvent resistance, etc.) and high versatility in chemical structures (discussed by Lu and Macosko [1]; reported by Cao et al [2]; studied by Oprea [3]; discussed by Akintayo et al [4]). Polyurethane based on polyols derived from different vegetable oils, like castor (discussed by Yeganeh and Hojati-Talemi [17]; studied by Corcuera et al [18]), soybean Yun et al [34] investigated PU grafted multiwalled carbon nanotubes (PU-g-MWCNTs) to fabricate electroconducting nanocomposites All of these studies were based on petroleum originated polyols; no study has been reported so far on green and renewable sources of polyols. The COPUs-MWCNTs polymer nanocomposite has been designed based on green and renewable castor oil as a polyol source, reinforced with purified MWCNTs to investigate the physicochemical behaviour of the synthesized polymer composites. In situ polymerization technique assisted by ultrasonication was adopted with different dispersion times of MWCNTs in the composite matrix to accomplish enhanced dispersion in the reacting mixture

Experimental

Characterization

Results and Discussion

Conclusions