Preparation Of Self-healing Elastomers Of Polyacrylate And Their Structural Color Properties

Since self-healing elastomer materials can repair the damage and can almost restore the original performance,thereby increasing the service life of the material,it has attracted more and more attention from scientific researchers.However,the self-healing properties and mechanical strength of elastomer materials have always been mutually restrictive properties.How to fabricate self-healing elastomers with a certain mechanical strength is still a hard work.In addition,for the aesthetics of the material,people usually add some dyes during the preparation process of the elastic material to give the elastic material a specific color.However,the use of a large number of chemical dyes will inevitably cause environmental pollution and other problems.Also,chemical dyes are susceptible to the light,temperature,etc.,which make the color of the material not lasting,thereby affecting the appearance of the material.Therefore,how to make elastic materials with durable colors and adjustable tones without polluting the environment is also a more meaningful research topic.Based on these two issues,this article mainly studies the improvement of the self-healing property and mechanical strength of elastomer materials,and at the same time considers the introduction of structural colors into the elastomer,giving the elastomer a bright color,and solving the problem of traditional dyes polluting the environment.The main content of the paper is as follows:(1)Using hydroxyethyl acrylate,hydroxyethyl methacrylate,and methacrylic acid as raw materials,a tri-monomer copolymer was obtained by polymerization initiated by ultraviolet light.Through the characterization of ultraviolet transmittance,thermal stability,mechanical properties,etc.,it is concluded that when the ratio of the three monomers is 3:2:1,the copolymer has relatively high tensile strength and tensile strain.Then the copolymer at this ratio is used as the skeleton,and low molecular weight polyacrylic acid is introduced to form a threedimensional interpenetrating network structure in the skeleton to further improve the mechanical strength of the polymer.Experiments show that when the amount of polyacrylic acid is 80% of the total monomer amount,the polyacrylate elastomer is formed with the best mechanical strength and tensile strain,which are 1.99 MPa and 170%,respectively.(2)By adding diallyl disulfide(DADS)as a crosslinking agent and modifier to the polyacrylate elastomer system,the dynamic reversible disulfide bond network,and a large number of hydrogen bonds in the system give the elastomer self-healing properties.By investigating the self-healing rate and degree of scratches on the surface of the elastomer and the comprehensive mechanical properties of the elastomer,it is concluded that when the DADS dosage is 0.5%,the elastomer has relatively higher mechanical properties.The tensile strength and tensile strain can reach 2.22 MPa and 180%.The elastomer has good scratch self-healing and fracture self-healing capabilities.At the same time,the influence of the time of the elastomer soaking in water and the heat-assisted temperature is explored.Finally,it is concluded that when the elastomer is soaked in water for 30 minutes and the heat-assisted temperature is about 60 ?,the elastomer has a good self-healing rate,and the morphology is nearly unaffected.(3)PS@(PMMA-PAA)nanospheres were synthesized by soap-free emulsion polymerization,and their nanoparticle size,microscopic morphology,infrared spectrum,etc.were characterized.At the same time,by adding polyvinyl alcohol(PVA)and carbon black(CB)to solve the problem of easy cracking and low color saturation of the structural colored films,and the optimal amounts of PVA and CB are 0.5% and 15% of the particle mass respectively.Then we designed and prepared the elastomer-photonic crystal-elastomer "sandwich" structural colored elastomer.Through the appearance,reflection spectrum,mechanical properties,solvent resistance and other characteristics of the structural colored elastomer,we found when the thickness of the top elastomer layer is less than 200 ?m and the thickness of the PCs layer is less than 50 ?m,the structural colored elastomer has the best performance in all aspects.At this time,the structural color elastomer has a bright structural color,crack-free and no iridescent effect,the maximum tensile strength and strain can reach 2.93 MPa and 150%,respectively,with a certain degree of solvent resistance and scratch resistance properties,which can be used in preparation Logos and toy products of various colors and shapes.