Design,preparation And Properties Of Photo-actuated Polymer Materials With Adjustable Structure

Photo-actuated polymer materials have an irreplaceable role in many fields such as artificial muscles,soft actuators,and biomedicine due to their unique and excellent properties.In order to further broaden its application range,molecular structure design is adopted to give it diversified functions.Intelligent development provides a basis,which has important practical significance and application value.However,current photo-actuated polymer materials still have problems such as difficulty in achieving high mechanical strength and high light-to-heat conversion efficiency at the same time,and inability to self-heal after damage.Therefore,this article focuses on the functional research of light-actuated polymer materials.In addition to basic actuated performance,it also further explores the realization strategies of shape memory,photothermal effect,pH responsiveness,and self-healing performance.(1)Based on the high mechanical strength and high photothermal conversion efficiency of the material,it is difficult to achieve,a double-network photo-actuated hydrogel with excellent mechanical properties,shape memory,photothermal responsiveness,and pH responsiveness was designed and prepared.Synthesized tripolyaniline(ACAT)monomer,and cross-linked it with N-isopropylacrylamide(NIPAM)and glycidyl methacrylate(GMA)to form a single network structure;prepared by the introduction of gelatin molecules double network hydrogel.The effect of gelatin molecules on improving the mechanical strength and shape memory of materials is explored,and the response relationship of ACAT to the mechanical strength of materials,photothermal response,pH response and other aspects is revealed.The results show that due to the introduction of the double network structure,its mechanical properties have been significantly improved(the maximum is 11.70 MPa),and give the material a better shape memory function(shape recovery rate of 100%),and the introduction of ACAT gives the hydrogel good photo-thermal response characteristics and pH responsiveness,its photothermal actuated degree can reach 28.58%.(2)Based on the fact that the material cannot be self-healed after damage during use,a dynamic cross-linking network of transesterification reaction was designed,and a self-healing photo-actuated thin film material was prepared.Synthesized 4,4’-diglycidoxy-azobenzene,carboxyl-terminated silica gel,side carboxyl silica gel and other monomers,and covalently cross-linked them to prepare main chain cross-linked polymer and side chain cross-linked polymer.The film-forming conditions of the main and side chain polymers were explored,and the influence of the degree of crosslinking on the mechanical properties and photo-actuated properties of the polymer was revealed,and the self-healing properties of the polymer were analyzed.The results show that the side-chain cross-linked polymer is easier to form a film than the main-chain cross-linked polymer.With the increase of the degree of cross-linking,the mechanical properties of the side-chain cross-linked polymer increase(the maximum is 0.1 MPa),and the photo actuated effect better(10%).Under the condition of 180℃×20 min,the side-chain cross-linked polymer showed good self-healing efficiency(about 76%).