Preparation And Modification Of EA Based Material For UV-curing Three Dimensional Printing

UV-curing three dimensional printing(3DP) is a unique advanced manufacturing technique which possesses the advantages of speediness, high efficiency and environment-friendly and is widely used for creating complex and fine entity parts. The scope and depth of 3DP applications are determined by the properties of 3DP materials. At present, limited variety, poor mechanical performance and high cost are the main challenges for the development of 3DP materials, so the exploitation of high-performance and low-cost materials is one of the core issues for UV-curing 3DP process.In this thesis, through the research of the main influencing factors on viscosity, UV-curing speed, curing degree, volume shrinkage and mechanical properties, the optimum formula of the epoxy acrylate(EA) based UV-curing 3DP materials with the advantages of low-viscosity, fast-curing and high mechanical properties was determined. Then nano-Si O2 and carbon nanotubes(CNTs) were used to improve the mechanical properties of the 3DP materials.The study of Si O2/EA based 3DP material showed that the silane coupling agent(KH570) modified nano-Si O2 might uniformly disperse in the matrix, which made great contribution to the mechanical properties of 3DP materials. When the nano-Si O2 content was 0.3 wt%, the tensile strength, flexural strength, flexural modulus and impact strength of the cured materials reached the maximum values, which was increased by 46.7 %, 243.4 %, 133.2 % and 18.8 %, respectively. Meanwhile, the fracture behavior of the 3DP materials transfered from brittle fracture to ductile fracture. The glass transition temperature of 3DP materials increased from 67.2 oC to 71.7 oC, and the volume shrinkage of the 3DP materials decreased by 12.1 % with 0.7 wt% CNTs, as well as the penetration depth decreased by 10.1 %. On the contrary, an increase of the critical exposure about 18.5 % was obtained.The study of CNTs/EA based 3DP material indicated that CNTs after heavily acid acidification and surface modification might uniformly be dispersed in the matrix without CNTs tangles, which made great contribution to the higher mechanical properties. When the CNTs content was 0.3 wt%, the tensile strength, flexural strength, flexural modulus and impact strength of the cured materials increased by 44.7 %?72.8 %?33.6 % and 17.8 %, respectively. Meanwhile, the fracture behavior of the 3DP materials transferred from brittle fracture to ductile fracture. The glass transition temperature of 3DP materials increased by 7.8 oC when adding 0.5 wt% CNTs. For the strong absorption of UV light, the penetration depth of the 3DP materials decreased by 19.3 % with 0.7 wt% CNTs, and an increase of the critical exposure about 43.0 % was obtained. Under this circumstance, the volume shrinkage of the 3DP materials decreased by 10.4 %.