Preparation Of Polyacrylic Acid-Based Composite Elastomers And Their Structural Color Properties

Structural colors originated from the interaction of light with periodic nano/micro physical structures,had broad application prospects in the fields of display materials,optical devices and other fields.The coordination elastic structural color materials with high mechanical stress,flexibility,mechanical fatigue resistance and solvent resistance can extensively improve their lifespan and applicantion range.However,at present,there are still the following problems in the study of coordination elastic structural color materials.The elastic structural color films had low mechanical stress,poor flexibility and mechanical fatigue property.In addition,the effect of solvent vapor on structural colors was not clear.In view of the above problems,polyacrylic acid-based coordination composite elastomers with different metal ions and elastic structural color materials were prepared by in-situ composite method and the principle of molecular compatibility in this thesis.Based on the principle of molecular compatibility,the hydroxyethyl methacrylate,hydroxyethyl acrylate and methacrylic acid copolymer with low glass transition temperature was used as matrix to realize in-situ composite with low molecular weight polyacrylic acid and colorless metal ions.Inside,main chains of low molecular weight polyacrylic acid were easy to stretch,coordination configuration was diverse.The coordination crosslinking reaction between metal ion and polyacrylic acid was controlled by the decomposition of urea,forming a tight entanglement structure of the coordination network with the copolymer.Polyacrylic acid-based coordination composite elastomer with high stress,mechanical fatigue resistance,excellent self-healing property and solvent resistance was prepared by adjusting the molar ratios of carboxyl groups of polyacrylic acid with metal ions.When the molar ratios of carboxyl groups of polyacrylic acid with Zn2+,Cd2+,Mg2+ were 1:0.5,1:0.5,1:0.4,respectively,the prepared coordination composite elastomer had excellent mechanical properties.Composite elastomer with Zn2+ had a tensile stress of 4.08 MPa at a tensile strain of 181%,strain energy to break of 5.33 MJ/m3,and a compression stress of 7.0 MPa at a compression strain of 80%.The tensile stress of composite elastomer with Cd2+ was 4.36 MPa at a tensile strain of 420%.Strain energy to break was 11.38 MJ/m3.The compression stress was 8.0 MPa at a compression strain of 74%.Composite elastomer with Mg2+ had a tensile stress of 3.07 MPa at a tensile strain of 585%.Compression stress reached 6.9 MPa at a compression strain of 78%.Coordination composite elastomer with high stress,flexibility and fatigue resistance was introduced into the microsphere gap of colloidal crystals,and colloidal crystals was locked.Tensile stress of the prepared Zn2+coordination elastic structural colors film reached 3.26 MPa.The color of the elastic structural color film remained unchanged after stretching,bending and compression fatigue.The elastic structural colors film possessed solvent resistance to water,methanol,ethanol,acetonitrile and chloroform vapor.Reflection peaks of Cd2+ coordination elastic structural color films remained unchanged after stretching for 600 consecutive cycles,bending for 300 consecutive cycles,compression for 300 consecutive cycles.The elastic structural color film exhibited excellent mechanical stability.The high molecular weight polyvinyl alcohol containing a large amount of hydroxyl groups which had good compatibility and weak interaction with copolymer of hydroxyethyl methacrylate,hydroxyethyl acrylate,methacrylic acid,was introducd into coordination composite elastomer forming multi-component tight structure.When the molar ratio of carboxyl groups of polyacrylic acid with Zn2+ was 1:0.5,the tensile stress,strain energy to break of the composite elastomer was 4.46 MPa at a strain of 501%and 12.88 MJ/m3,respectively.Reflection peaks of the prepared elastic structural color films remained unchanged after stretching for 600 consecutive cycles,bending for 600 consecutive cycles and compression for 400 consecutive cycles.The elastic structural color films exhibited excellent mechanical stability.