Nanocomposites of cellulose-based adhesive and toluenesulfonic acid-doped polypyrrole prepared via colloidal dispersion

Abstract

Nanocomposites of cellulose-based adhesive and doped polypyrrole (PPy) have been prepared via colloidal dispersion method. Cellulose was chemically modified with epoxy to incorporate adhesion property. PPy nanoparticles were synthesized via oxidation reaction using toluenesulfonic acid as a doping agent. Field emission scanning electron microscope, Fourier transform infrared spectroscopy, thermogravimetric analysis, elemental analysis and high-frequency impedance spectroscopy were used to characterize the nanocomposites. Toluenesulfonic acid-doped PPy synthesized at pH 1 resulted in rod-shaped particles with a diameter and a doping level of about 80–100 nm and 25%, respectively. Toluenesulfonic acid-doped PPy synthesized at pH 3 and pH 4 produced spherical-shaped particles with doping level of 21% and 17%, respectively. Toluenesulfonic acid-doped PPy particles synthesized at pH 3 is smaller (76–100 nm) compared to the one prepared at pH 4 (97–254 nm). The electrical and thermal conductivities obtained for toluenesulfonic acid-doped PPy synthesized at pH 1 were 8.422 × 10⁻³ S cm ⁻¹ and 0.431 W m ^{− 1}  K ^{− 1} , respectively. Whereas, the one synthesized at pH 3 and pH 4 exhibited lower electrical and thermal conductivities. Nanocomposite with a composition of 70 : 30 (toluenesulfonic acid-doped PPy:epoxypropyl cellulose) gave the highest electrical and thermal conductivities.