Synthesis And Properties Of UV Curing Oligomers Containing 9,9'-diarylfluorene

High refractive index polymer has the characteristics of light weight and easy processing.It is one of the most widely used optical materials currently.Its application in optical coatings is also a hot research direction in recent years.The base material of optical coatings is usually polymeric lens,which is suitable for UV curing methods with the advantages of low curing energy consumption,low VOC content and low substrate loss.9,9'-Diarylfluorene is a common structure with high refractive index.Incorporating this group into the polymer can increase the overall refractive index.However,polymers with this structure usually have problems such as high viscosity,which is not conducive to coating,strong rigidity and insufficient flexibility.Therefore,the development of high refractive index photocurable resins with low viscosity and excellent flexibility has become one of the problems faced by UV-curable optical coatings.Based on the above issues,this project has carried out the following research:(1)Using acrylic acid modified caprolactone and epoxy bisphenol fluorene as raw materials,we get a series of?-caprolactone modified epoxy bisphenol fluorene acrylate(AAPD).The structure and molecular weight of the product resin were characterized by FT-IR,~1H-NMR and GPC etc.The produced coatings and unmodified coatings in terms of viscosity,refractive index and mechanical properties etc were compared.The results show that the refractive index of the produced coating APD can be reduced by 2.84%at the highest,and the viscosity can be reduced by 65.27%at the lowest.In addition,the produced coating APD also has excellent flexibility and tensile fracture resistance with the maximum elongation at break40.52%and the maximum deformation energy 9.771 MJ/m~3.(2)Using?-caprolactone,diether fluorene and acryloyl chloride as raw materials,a series of?-caprolactone modified bisether fluorene acrylates(BCAC)were prepared.The structure and molecular weight of the produced resin were characterized by FT-IR,~1H-NMR and GPC,etc.The BCAC coatings,AAPD coatings and unmodified resin coatings in terms of viscosity,refractive index,mechanical properties etc were systematically compared.As a result,under the premise of the same refractive index,the viscosity of the BCAC coatings can be further reduced by 89.05%compared with the AAPD coatings.In addition,BCAC coating also maintains excellent basic film properties and tensile fracture resistance.(3)Using BCAC resin as the matrix resin,a series of UV-curable high-refractive wear-resistant coatings are formulated through the optimization of reactive diluents.The results show that the refractive index of the prepared UV curing coating is above 1.55 and the viscosity is lower than that of the unmodified resin coating.The coating also has excellent abrasion resistance.The surface fading loss of 1:0.5-DPHA after 20,000 rubs is only 0.73%.The maximum tensile stress can reach 67.35 MPa,and the maximum Young's modulus can reach2319.28 MPa.