Preparation And Application Of High-Performance Styrene-Acrylate Resin

Styrene-acrylate(SA)resin is a kind of commercialized multifunctional resin material with good adhesion,pollution resistance,scrub resistance,deformation adaptability and low production cost,which is now widely used in aerospace,construction,energy and electronics.But traditional SA materials still have many defects,such as poor mechanical properties,high water absorption,lack of self-healing and fatigue resistance,so it is a problem to be solved to propose an effective modification method.In this thesis,styrene-acrylate resin materials modified with functional monomers were prepared by introducing monomers with functional groups into SA systems,and we focused on the effects of monomers on thermodynamic properties,self-healing,and application aspects of SA resins.The specific work is as follows:1.SA latexes with different GMA contents were prepared by semi continuous seed emulsion polymerization using styrene(St),butyl acrylate(BA),acrylamide(AM),and glycidyl methacrylate(GMA).TGA results indicated that the introduction of GMA improved the thermal stability of SA.Shao's hardness test showed that the increase of GMA content significantly increased the hardness of SA,which reached 76 A.Water absorption experiments showed that the addition of GMA increased the degree of crosslinking of SA and thus decreased its water absorption.2.DEI and IBOMA modified SAD and SAD₄I resins were prepared by semi continuous seeded emulsion polymerization using styrene(St),butyl acrylate(BA),acrylamide(AM),glycidyl methacrylate(GMA),diethyl itaconate(DEI)and isobornyl methacrylate(IBOMA)as monomers,respectively.FT-IR results showed that both monomers of DEI and IBOMA were successfully introduced into the SAD and SAD₄I backbones,respectively.Mechanical properties tests of SAD and SAD₄I resins showed that the addition of DEI increased the content of ester groups in SAD polymer chains with different DEI contents,and the plasticization of ester groups increased the tensile strength of SAD resin from 12.6 MPa to 20.4 MPa,the Young's modulus from 3.81 MPa to 26.57 MPa,and the hardness increased to 83.6 A,but the elongation at break decreased to 1405%.The bulky and rendered rigid isobornyl group of IBOMA monomers affected the movement of SAD₄I chains,the tensile strength and elongation at break decreased to 19.2 MPa and 1228%,respectively,but its Young's modulus increased to 66.8 MPa,and the hardness increased to 89.6 A.TGA and DSC showed that the DEI did not affect the thermal stability of SAD resins,but the effect of ester groups on the polymer chains decreased the T_g.The introduction of IBOMA decreased the thermal stability but increased the T_g of SAD₄I resins.Water absorption experiments showed that SAD and SAD₄I resins had lower water absorption,which illustrated that both DEI and IBOMA could improve the water resistance of resins.Antibacterial test results illustrated that bacterial adhesion was reduced by polymer surface stereochemistry due to the introduction of isobornyl groups on the polymer backbone of SAD₄I resin.SAD₄I exhibited 86%bacteriostatic efficiency against Escherichia coli(gram negative),indicating the unique antibacterial adhesion property of IBOMA monomers.3.SA latex was prepared by semi continuous seed emulsion polymerization using styrene(St),butyl acrylate(BA),glycidyl methacrylate(GMA)and acrylamide(AM)as monomers.The CMCS composite SACS resin was prepared by mixing carboxymethyl chitosan(CMCS)aqueous solution with SA latex.Carbon nanotube aqueous dispersions(CNTs)were sprayed on the surface of SACS resin and SACS conductive resin film was obtained after spraying five times.We also focused on the mechanical properties,thermal stability,fatigue resistance,self-healing and electrical conductivity of SACS.The formation of multiple type reversible hydrogen bonds between SA polymer chains and CMCS and the rigid framework formed by CMCS in SA,resulting in a SACS resin with a tensile strength of 17.9 MPa and a high breaking elongation of 2148%.This was a greater lift compared to SA films without added CMCS.CMCS effectively increased the hardness of SACS resin,and the Shao's hardness increased to 80.6 A,which can be used as a high hardness resin material.Cyclic tensile test results showed that SACS resin exhibited fatigue resistance and thermal repair ability.The self-healing test indicated that after composite CMCS,the SACS resin was endowed with a certain self-healing performance due to the polytypic hydrogen bonding interactions formed between CMCS and SA molecular chains,with a repair efficiency of 68.7%.TGA and DSC results showed that the introduction of CMCS increased the thermal stability of SACS resin,and decreased the glass transition temperature(T_g).T_gdecreased from 16.2°C to 13.1°C.Electrochemical tests indicated that CNTs formed a conductive network on the surface of SACS conductive resin film and the electrical conductivity gradually became larger with the increasing number of CNTs layers.In addition,the SACS conductive resin film could sense the current signals produced by tiny movement changes(e.g.,smiling,fisting,etc.),which illustrated the potential application of SACS conductive resin film in the field of sensors.