Preparation And Characterization Of Urushiol Based Photocuring Nanocomposite Coatings

In this paper,the main component of lacquer,urushiol,has been studied in depth.In order to solve the problems of harsh film forming conditions and poor mechanical properties of urushiol,urushiol epoxy acrylic(UEA),which can be UV curable and has excellent properties,was prepared by reacting urushiol with epoxy resin and acrylic acid.Then using UEA as matrix,the mechanical properties of the composite films were further improved by adding graphene oxide,nanocellulose and fiber nano-reinforced fillers.In this study,GO,MPS-GO,ODA-GO was used as reinforcing filler.By c modified graphene oxide nanocellulose fibers were used as reinforcing fillers in different proportion of MPS as modification auxiliaries.Preparation of modified graphene oxide nanocellulose / epoxy acrylic composite coating.By comparing the mechanical properties of the composite coating,the optimum ratio of GO to CNF is 1: 3.By comparing the mechanical properties of the composite coating,the optimum mass ratio of GO-CNF fillers to UEA is 1%.Finally,infrared,scanning electron microscope,X-ray diffraction and X-ray photoelectron spectroscopy were used to analyze the optimal composite coating characteristic groups,apparent morphology,element content and chemical structure.The conclusions are as follows:(1)The addition of GO can significantly improve the hardness of UEA film,and it is also easy to lead to agglomeration and embrittlement of paint film.Compared with pure UEA film,the highest hardness and impact resistance of GO/UEA film are 5H and 42 cm,respectively,but the adhesion and flexibility of GO/UEA film decrease obviously.(2)After modification of GO,the long chain carbon molecules of ODA and the silane molecules of MPS were effectively ligated to the surface of GO,which effectively solved the agglomeration problem of GO in the paint film and enhanced the compatibility of GO and matrix.Compared with MPS-GO/ UEA,ODA-GO/ UEA has higher flexibility,impact resistance and hardness,which is due to the fact that ODA-GO and matrix UEA are more likely to cross-link and have better compatibility.GO can be used as reinforcing filler to disperse uniformly in the gap between UEA polymer molecules,and to increase the compactness and integrity of the film.(3)By comparing the mechanical properties of MPS-GO/UEA film and ODA-GO/UEA film,it is found that the hardness and flexibility of MPS-GO coating are not significantly different from those of ODA-GO coating.Although the adhesion and impact resistance of ODA-GO coating is better than that of MPS composite coating,ODA is expensive,toxic and does not conform to the concept of green environmental protection.Therefore,using MPS as modification agent,the adhesion and impact resistance of coating can be improved by adding nano-cellulose fiber(CNF),and the addition of CNF can reduce the amount of GO,thus reducing the cost of coating.(4)By comparing the mechanical properties of GO-CNF composite coatings with different proportion of MPS as modification auxiliaries and different contents(mass ratio of UEA),the optimum content of composite coating fillers is 1%,and the optimum ratio of GO: CNF=1: 3.The optimum hardness of the coating is 5H,the adhesion is grade 1,the impact resistance is 50 cm,and the flexibility is grade 2.Its adhesion and impact resistance have been significantly improved,and the mechanical properties of ODA-GO coating have reached the same level.At the same time,the cost of the coating has been greatly reduced,and it is also in line with the development concept of green environmental protection.