Preparation And Properties Of Conductive Polyurethane Based On Deep Eutectic Solvents

Flexible conductive materials are an important part of the next-generation flexible electronic devices,their excellent performance is the basis for the development of related devices.Conductive polyurethane has good mechanical properties and excellent electrical properties,and has been widely used in flexible displays,electronic skins,sensors and other intelligent devices.At present,there are two types of conductive polyurethane: one is electronic conductive polyurethane with electronic conductor filler;the other is ion conductive polyurethane with ion conductor filler.Since the doped electronic fillers are often metals,carbon materials or semiconductor materials,the former has the problem of reducing the original transparency and flexibility.Due to the huge polarity difference between the ionic dopant and the polyurethane substrate,there are problems such as phase separation and liquid leakage during use.To solve these problems,an environmental friendly Deep Eutectic Solvents(DES)is innovatively introduced into polyurethane by copolymerization.The prepared conductive polyurethane has high transparency,good mechanical properties,solvent resistance and conductivity,which can be used for pressure detection.At the same time,the material can be given a certain self-healing property through structural design.The research content of this paper is as follows:First,a DES was prepared using hydroxyethyl methacrylate(HEMA)asthe hydrogen bond donor,which was copolymerized with a polyurethane prepolymer containing MDI50 and terminated by HEMA,and a series of conductive polyurethanes were prepared by changing the composition ratio of DES.The successful synthesis of conductive polyurethane was proved through structural and morphology characterization.The optical properties,mechanical properties,solvent resistance and electrical conductivity of the prepared polyurethane were tested,and it was found that it retained the good optical transparency,mechanical properties and solvent resistance of the polyurethane system.On this basis,it also has good electrical conductivity and can be applied to a wide range of pressure sensing tests.Secondly,a DES was prepared by using hydroxyethyl acrylate(HEA)as the hydrogen bond donor.This DES was copolymerized with a polyurethane prepolymer containing isophorone diisocyanate(IPDI),terminated by HEMA and modified by disulfide bonds..By changing the composition ratio of DES,a series of conductive polyurethanes with self-healing properties were prepared.The successful synthesis of self-healing conductive polyurethane was proved through structural and morphology characterization,and the optical properties,mechanical properties,solvent resistance and electrical conductivity of the prepared polyurethane were tested.It was found that it still retained the good optical transmittance,mechanical properties and solvent resistance of the polyurethane system,as well as its good electrical conductivity.It has a sensitive and stable response to external pressure.At the same time,the introduction of disulfide bond endows it with self repair ability,which can realize the repair ability of surface scratches at a certain temperature.