Preparation And Properties Of Self-healing Silicone Rubber Based On Hydrogen Bonding

Traditional elastomer composite materials are easily damaged by various external factors（light,heat,mechanical damage）during application,which will greatly reduce the service life of the material.Therefore,the preparation of high-performance elastomeric composites with self-healing properties has broad research prospects.In this paper,three kinds of elastomer materials with self-healing properties were prepared based on reversible non-covalent bonds（hydrogen bonds）,and their structures and properties were investigated.The specific research contents are as follows:1.The methyl vinyl silicone rubber（MVSR）containing vinyl active groups was used as the matrix material for research,and 2-isocyanate ethyl acrylate（ICA）was used as a chain extender to react with MVSR,and 2-amino-4-Hydroxy-6-methylpyrimidine（UPY）modified it to prepare a superstretch self-healing elastomer material（MVSR-UPY）containing quadruple hydrogen bonds.Its structure was characterized by infrared spectroscopy,hydrogen NMR spectroscopy,swelling test and other tests,which proved that the synthetic route of the projectile was correct.Its properties were characterized by tensile test and repair test,which proved that the elastomer has good mechanical properties,repair properties and reprocessing properties.Based on MVSR-UPY,a self-healing flexible sensor with high sensitivity and durability was prepared,which can accurately monitor various activities of the human body.Repair testing proved that the damaged and repaired sensor still had high sensitivity.It is worth noting that writing different letters on the sensor produces different resistance signals,which differentiate the different letters.2.The bis（3-aminopropyl）-terminated polydimethylsiloxane（HN₂-PDMS-NH₂）containing amino reactive groups was used as the matrix material,and isophorone diisocyanate（IPDI）was used as the extension The chain agent reacted with HN₂-PDMS-NH₂,then it was further modified with 2,4-dihydroxypyridine（DHP）,and finally,Fe³⁺was introduced to coordinate with the ligand,and the two compounds containing hydrogen bonds and metal coordination bonds were prepared.A reversible non-covalent self-healing elastomeric material.The structures were characterized by FT-IR,¹H NMR and UV spectroscopy,which proved that hydrogen bonds and metal coordination bonds were successfully introduced into the system.The repair performance test shows that the elastomer material has excellent self-healing ability,and can even complete the repair at room temperature.3.HN₂-PDMS-NH₂ was used as the matrix material for the study,and IPDI was used as a chain extender to react with HN₂-PDMS-NH₂ to introduce the active group-NCO into the main chain,followed by 2,2′-diaminodiphenyldisulfide.After further modification,a high-strength self-healing elastomer material containing two reversible chemical bonds,hydrogen bond and disulfide bond,was prepared.The structures were characterized by FT-IR and ¹H NMR,which proved that hydrogen bonds and disulfide bonds were successfully introduced into the system.The test of mechanical properties shows that the introduction of di-membered benzene ring and disulfide bond endows the elastomer with extremely high mechanical strength.The repair performance test shows that the elastomer material has a certain self-healing ability.