Carbon nanotube reinforced self-healable polythiourethane with excellent bonding strength and improved thermal conductivity

The market demand for high performance engineering materials, which have both strong mechanical properties and excellent self-healing capability, has increased sharply with the development of industrialization. Therefore, to endow the mainstream engineering materials with self-healing properties is a promising and challenging work in dynamic chemistry. Herein, we present carbon nanotube (CNT) reinforced self-healable polythiourethane (PTU) with excellent lap shear stress and improved thermal conductivity for high performance engineering materials. The undoped PTU from an optimized system has a lap shear stress of 9.36 MPa, 100% optical transmittance, and 95% self-healing efficiency of the original mechanical properties, which can enable a lap shear specimen to load over 27.72 kg weight with 0.02 g PTU in a field of 10 mm x 10 mm. The lap shear stress of the 0.3 wt% CNT doped PTU was further improved to 12.2 MPa, which is the highest among those of the reported composite materials constructed by dynamic bonds. The thermal conductivity of a 1.0 wt% CNT doped PTU adhesive is greatly improved by nearly 400% compared to those of the traditional polyurethane materials. Therefore, this kind of CNT reinforced novel polyurethane material shows great potential in high performance polymer composite materials.