| In 3D printing,the most widely used and the most in-depth research is the light curing rapid prototyping technology.The materials that can be used in light curing rapid prototyping technology are mainly photosensitive materials.It is mainly composed of initiators,prepolymers,monomers,etc.,and can be cured under the irradiation of a certain intensity of laser.Epoxy-type photosensitive resin occupies the majority of photosensitive materials.The cured product of epoxy-type photosensitive resin has excellent mechanical properties and small dimensional shrinkage,but at the same time it is more expensive and rare in types.Therefore,the development of new epoxy-type photosensitive resin has good research value.Development has a driving effect.In this paper,3-ethyl-3-allylmethoxyoxetane and 1,1,3,3-tetramethyldisiloxane were used for the hydrosilylation reaction to synthesize a new type of cation Type oligomer,1,3bis[(3-ethyl-3-methoxyoxetane)propyl]tetramethyldisiloxane,and use it as a photosensitive prepolymer to prepare a A new type of photosensitive resin,and its UV curing performance has been studied,and it has been applied to 3D printing stereolithography technology to make molds and parts printing experiments.The specific research content is as follows:(1)Firstly use 3-ethyl-3-hydroxymethyloxetane and allyl bromide as raw materials,and use tetrabutylammonium bromide as a catalyst to synthesize the active monomer 3-Ethyl-3-allylmethoxyoxetane.Then 3-ethyl-3-allylmethoxy oxetane and 1,1,3,3tetramethyldisiloxane were used for the hydrosilylation reaction to synthesize a new type of C ationic UV-curable prepolymer,1,3-bis[(3-ethyl-3-methoxyoxetane)propyl]tetramethyldisiloxane,and explored the polymerization method and reaction The influence of material ratio,reaction temperature and reaction time on the reaction.The experimental results show that the ratio of 3-ethyl-3-allylmethoxyoxetane to 1,1,3,3tetramethyldisiloxane is 2.2:1,and the reaction temperature is 90 The reaction is most complete at?,the reaction time is 3 hours,and the holding time is more than 4 hours to obtain a reaction product with a higher conversion rate.Through Fourier infrared spectroscopy FT-IR,hydrogen nuclear magnetic resonance spectroscopy,and carbon nuclear magnetic resonance spectroscopy,it can be proved that the product obtained is the target product,that is,1,3-bis[(3-ethyl-3-methoxy oxygen heterocycle Butane)propyl)tetramethyl disiloxane(2)The target product 1,3-bis[(3-ethyl-3-methoxyoxetane)propyl]tetramethyldisiloxane synthesized in the experiment is used as the prepolymer,and triarylsulfonium hexa Fluoroantimonate(UVI-6976)was used as the initiator to prepare photosensitive resin.And adding active monomer DH306 to prepare a mixed system photosensitive resin.Using Fourier Transform Infrared(FT-IR)to study the UV curing system,the characteristic peaks of epoxy have basically disappeared,confirming the curing mechanism of this type of epoxy-containing photosensitive resin.The rate of curing of the synthesized product and E-51 was tested by Photo-DSC,and the results showed that the synthesized product had better photosensitivity.By testing the properties of different formulations of photosensitive resin Fourier transform infrared(FT-IR),TGA,tensile strength,flexibility,damping hardness,and impact strength,the flexibility and tensile strength of the resin of the hybrid system after curing,Elongation at break,Young's modulus of elasticity,impact strength and flexural strength are 4mm,5.4MPa,1.7%,206.56MPa,25 Kg.cm,12.19 Kg.cm,and the flexibility of the pure cationic resin after curing The properties,tensile strength,elongation at break,Young's modulus of elasticity,impact strength and bending strength are 3 mm,22.15MPa,2.4%,2807.01MPa,30Kg.cm,25.15 Kg.cm,respectively.The results show that the mechanical properties of pure cationic photosensitive resin are more excellent,while the flexibility of hybrid photosensitive resin is better.Generally speaking,pure cationic photosensitive resin has better practical effect.(3)With synthetic 1,3-bis[(3-ethyl-3-methoxyoxetane)propyl]tetramethyldisiloxane as the main component,with triarylsulfonium hexafluoroantimonate The salt propylene carbonate solution is a cationic initiator,and some additives are added to prepare a new type of photosensitive resin.When printing with HRPL-150 A stereolithography rapid prototyping equipment using it as a raw material,set the temperature to 30?,and set the layer thickness,scanning pitch and scanning speed to 0.10mm,0.08mm,and 1200mm/s,respectively.Printed under this condition,the mechanical properties ofthe printed parts are good. |
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