Effects of carbon nanotube and curing agent concentrations on the mechanical, thermal and electrical properties of polydimethylsiloxane: optimization and statistical analysis

Abstract

This study examined the combined impact of carbon nanotubes (CNTs) and curing agents on the mechanical properties (tensile strength and modulus of elasticity) and thermal and electrical conductivities of polydimethylsiloxane (PDMS) using statistical analysis. PDMS composites were created by varying the concentrations of CNTs (0% to 5%) and curing agents (0% to 0.5%), and their properties such as tensile strength, modulus of elasticity, and thermal and electrical conductivities were comprehensively analyzed. Mechanical tests revealed that adding 5% CNT and 0.5% curing agent increased the tensile strength by 50% and modulus of elasticity (Young's modulus) by 65%, indicating a substantial reinforcing effect. Thermal conductivity remarkably improved from 0.2 W m⁻¹ K⁻¹ in pure PDMS to 1.1 W m⁻¹ K⁻¹ in the composite containing 5% CNT and 0.5% curing agent. The electrical conductivity improved significantly from an insulating 10⁻¹⁴ S m⁻¹ to 10⁻² S m⁻¹. This indicated a shift to conductive PDMS at higher CNT concentrations. Statistical analysis showed that CNTs had more significant impact on electrical and thermal properties, while the curing agent mainly enhanced the mechanical stability. These results highlight the combined potential of CNTs and curing agents in modifying PDMS properties for advanced engineering applications.