Preparation Of Photosensitive Resin For Photocuring Rapid Prototyping And Its Toughening Modification

Three-dimensional printing is a new technology and it has developed quickly during recent years, compared to the traditional less material manufacturing and increasing material manufacturing, the new technology has been recognized by everyone because of its convenience, novelty and speedy, three-dimensional printing shows its superiority in relevant areas especially for some products of complex shape and fine construction, and its rise has been called the "third industrial revolution."The technology of three-dimensional printing has three elements: material, equipment and related software, they're indispensable, and material is the most important. At present,most of the domestic photosensitive resin for SLA rely on imports, and there are few empirical researches related to it in our country, even the products appear a variety of drawbacks, such as the phenomenon of serious layering and poor toughness. Therefore, this paper carries out the related jobs, and we obtain a kind of excellent photosensitive resin,named LPR-1. The main works are as follows:Firstly, designing and preparing the photosensitive resin, studying the factors about oligomer, active diluent and UV initiator. Experimental results revealed that: using epoxy acrylate/polyurethane acrylate as oligomer with a ratio of 6:5 and the total content of 60%;using dipropylene glycol diacrylate(DPGDA)/trimethylolpropane trimethacrylate(TMPTMA) as active diluent with the total content of 35%; using 2,4,6-trimethyl benzoyldiphenyl phosphine oxide as the main initiator, 4-(N,N-dimethyl amine) benzoic acid ethyl ester as Amine co-initiator, Irgacure184 as coinitiator with the total content of 4%.The resin has excellent performance including coagulum content, shrinkage-rate, viscosity,curing rate, and mechanical properties in this condition, and it can satisfy the basic requirement of the relevant materials.Secondly, obtaining NR-MAH-HEMA based on the natural rubber(NR) by grafting maleic anhydride(MAH) and hydroxyethyl methylacrylate(HEMA) by synthetic technology.Experimental results revealed that: selecting NR as matrix, MAH 5.3%,dicumyl peroxide(DCP)/tetraethylenepentamine(TEPA) 1.7% with a ratio of 2:1, setting the reaction temperature 138?, the rotor speed 55r/min, the reaction time 3.5min, the graft ratioand graft efficiency of the graft polymer NR-g-MAH reach the highest level in this condition; using dimethylformamide(DMF) as solvent, p-toluenesulfonic acid as catalyst with the content of 1%, using n(acid anhydride groups): n(hydroxyethyl methacrylate)=3:5,setting the reaction temperature 100?, the reaction time 5h, the esterification rate of the graft polymer NR-MAH-HEMA reach the highest level in this condition. It is grinded into powder by freezing it in liquid nitrogen.Finally, filling resin with SiC whiskers and NR-MAH-HEMA powder, experimental results revealed that: the modified SiC whiskers with KH-560 are better than the SiC whiskers before modification, and the resin has great performance with 2% SiC whiskers and 4% NR-MAH-HEMA powder when they fill alone, to achieve better results, thinking about the solidified depth, solidified time, coagulum content, shrinkage-rate, viscosity and mechanical properties of the photosensitive resin, using modified SiC whiskers and NR-MAH-HEMA powder with a ratio of 1:1 and the total content of 2% when they fill together.