Study And Application Of Material In Stereolithography

The study of photosensitive resin is a key procedure in Stereolithograghy (SL).The properties of Ultraviolet(UV) photosensitive resin which are used in SL at present were modified, and new visible photosensitive resins were exploited on the basis of UV photosensitive resin.In the field of UV photosensitive resin, the mechanism of curing, the matching degree of resin-illuminant and the factors affecting the performance of resin were studied in detail. The epoxy acrylate with excellent properties was synthesized, and the resin fit for SL was brought out by using the prepared prepolymer as well as the synergistic initiators which are sensitive to UV light.In view of the high rate of volumetric shrinkage, UV photosensitive resin was modified by adding spiro orthocabonate 1,5,7,1 l-tetraoxasplro[5,5]undecane which is expandable, the results show that the rate of volumetric shrinkage of the resin decreases by 3.2% to 1.3% with adding 15% spiro orthocabonate and the intergrated properti esof the resin are still good.In the field of visible photosensitive resin, the absorption spectrum, excited state,solvent polarity effect, fluorescence spectrum, fluorescence quenching, concentration effect, photo fading, reaction mechanism as well as photopolymerization kinetics of xanthene iodonium salts and cyanine dye-borate were discussed. It is found that under the radiation of visible light, intra-ion-pair electron transfer reactions occur in bis(diphenyliodonium) salt of fluorescein and unsymmetrical trimethine cyanines containing quinoline end group triphenyl-butylboron, and the fading rate is very high. Two kinds of new visible photosensitive resin, which are sensitive to 511nm and 680nm visible light, were exploited by using these two initiators, and the properties of the resin were also stuied.