Preparation And Properties Of The Self-healing Metal Complexed Polyurethane/Ion Conductors

The polyurethane has the excellent chemical and adjustable mechanical properties.It is widely used in daily life and industrial production according to different physical and chemical properties.However,these materials are often subject to tear and partial breakage during use,so materials with self-healing properties can effectively extend the life of the device.However,materials with self-healing properties are generally relatively weak in mechanical strength,and their relatively weak mechanical strength limits their application.In addition,the introduction of conductive ions into the polyurethane matrix to construct a conductive sensor device with self-healing properties and response to water vapor without losing its mechanical properties is also a difficult problem to be solved in the current self-healing conductive materials.This thesis conducts research on these two aspects,as follows:First,we prepared a polyurethane elastomer with high mechanical properties and high self-healing properties.In this experiment,we introduced a mono-pyridine ligand into a polyurethane and then complexed it with a metal ion to form a polyurethane elastomer having high mechanical properties and high self-healing coexistence.The mechanical strength of the polyurethane elastomer is achieved by adjusting the proportion of each monomer in the polyurethane and the coordination number of the pyridine ligand to the metal ion.The self-healing properties of the elastomer are provided by strong reversible coordinate bonds between the metal Fe²⁺ions and pyridine and weak other coordinate bonds.The prepared polyurethane elastomer has high mechanical tensile properties?stress 4.64 MPa,strain 497.5%?,high fatigue resistance?50 stretching cycles?,the stress self-healing efficiency of 96%at room temperature,and up to 30%repair efficiency at 5?.More importantly,the polyurethane elastomer is insensitive to the notch and has a fracture energy of up to 76186 J/m².Another work in this paper is to prepare a vapor-sensitive polyurethane ion conductor.In this work,we also introduced the mono-pyridine ligand into the polyurethane and then complexed it with the Zn²⁺ion.A vapor-sensitive polyurethane ion conductor can be obtained by adding a conductive medium lithium salt to the complexed polyurethane provides conductivity by controlling the different mass fractions of the conductive ions.Through a series of test analysis,we can see that our samples have excellent mechanical properties?stress 0.8 MPa,strain 2800%?as well as self-healing properties,ionic conductivity,and more interestingly,our samples also have the characteristics of being sensitive to water vapor in the air.For samples,it can cause a change in the resistance number when absorption of water vapor in the air,polyurethane ion conductors with 50%lithium salt content are most prominent.