Preparation And Properties Of Self?healing Organosilicon Elastomer

In recent years,there have been plenty of research on self?healing materials,which are of great significant for the manufacture of renewable and reusable polymer materials.The self?healing materials are mainly divided into intrinsic and extrinsic types,while the former can be divided into self?healing materials based on reversible covalent bond and reversible non?covalent bond.In this paper,a self-healing polysiloxane elastomer was designed and synthesized by using the reversible Diels?Alder bond as the crosslinking points and the main reversible self?healing bonds,the coordination between the Fe(III)ion and the ligand as the auxiliary repair bond and performance enhancement structure,and polysiloxane as the main chain to provide flexibility.In this paper,by regulating the proportion of metal coordination bond in the self-healing group,the effects of each interaction on the self-repairing performance and other properties,and the repair mechanism of self?healing organosilicone elastomer were studied.Self?healing functional polysiloxane monomers containing functional groups of furan and maleimide was synthesized,and Infrared Spectroscopy(IR)and Nuclear Magnetic Resonance Spectroscopy(H?NMR)were utilized to characterize their structures.Two kinds of coordination bond structures were obtained by different synthesis paths,and the relative strength of each coordination bond was characterized by tensile test.The curing conditions of the mixed system were investigated,and the proportion of each monomer component was adjusted to prepare self-healing elastomers with different structures.Tensile test was utilized to study the mechanical properties of the elastomer,Differential Scanning Calorimetry(DSC)test,Rotational Rheology test and Thermogravimetric Analysis(TGA)were utilized to study the thermodynamic properties of the elastomer,and thermal decomposition kinetic analysis was performed.Finally,the self-healing ability of self?healing elastomers was studied by a variety of characterization methods.According to the comprehensive analysis of all characterization results,it was found that the ligand structure was the most ideal structure with the proportion of 80 % of the self?healing group,and the self?healing polysiloxane system in the application field was adopted.In this paper,the healing mechanism of self?healing organosiloxane crosslinking network was studied by healing experiments,and it was discovered that the self?healing process of crosslinking network depends on cooperation of Diels?Alder with mental coordination bonds.Diels?Alder bonds supply strong chemical bonds and introduce the mechanism of thermal stimulated self?healing.What's more,the mental?ligand structure provides a great healing method utilizing its unique coordination bonds with strong?middle?weak bond energy,which can enhance the healing efficiency of crosslinking network effectively.Furthermore,the features of self?healing network was utilized to design a self?healing coating,which can be applied on protection of equipment.