| Epoxy acrylic resin has the advantages of fast curing speed,high gloss,good chemical resistance and low price.It is the most widely used photosensitive oligomer in the field of UV curing.However,due to its hardness,tensile strength,gel content and curing shrinkage rate,it cannot meet the market demand.Therefore,it is important to modify epoxy acrylic resin.For bisphenol A type epoxy acrylates prepolymer,when technological conditions as follows:light initiator for 819,1.6%light initiator content,reactive diluents for HDDA,bisphenol A type epoxy acrylate and thinner proportion is 1:0.8,the solidifying product forming fastest single exposure to 10 s,the tensile strength of 28.25 MPa,gel content is 82.16%,curing shrinkage rate of 6.91%.When the samples are aged for 30min,the maximum hardness is 51 HA,and the maximum tensile strength is 29.19MPa.When the samples are aged for 60min,the maximum gel content is 83.23%.However,the surface morphology of some solidified samples show cracks,and the number of cracks increased with the increase of aging time.Bisphenol A epoxy acrylate is selected as the prepolymer,HDDA as the diluent,819 as the photoinitiator,and the ratio of bisphenol A epoxy acrylate to the diluent is 1:1.When BMI content is 2%,the printing time of the photosensitive resin system is shortened and the molding precision is improved.The single layer exposure time of the sample is 8s.Meanwhile,the curing shrinkage rate is reduced from 9.73%to 6.38%,the tensile strength is increased from 22.28MPa of the pure photosensitive resin system to 37.45mpa,and the gel content is increased from 76.27%to 87.25%.The maximum tensile strength is 33.06mpa,the maximum hardness is 68HA,and the curing shrinkage rate is 6.81%.However,when the content of ultra-fine powder ZrO2 exceeds 1.5%,the viscosity of the system reaches 954mPa · s,which cannot meet the requirements of 3D printing. |
PDF Full Text Request