Preparation And Optical Performance Of THFMA/PQ/PMMA Photopolymers

Polymethyl methacrylate(PQ/PMMA)photopolymers have attracted increasing attention due to high quality holographic properties and the ability to be prepared into large size samples.However,the practical application of PQ/PMMA in holographic storage is limited by long response time and low diffraction efficiency.Therefore,it is a very significant topic optimizing and improving the PQ/PMMA material to enhance its optical holographic performance.In this thesis,a novel THFMA/PQ/PMMA photopolymer was prepared by doping tetrahydrofurfuryl methacrylate monomer in a PQ/PMMA photopolymer system.The preparation method,holographic properties and photochemical reaction kinetics of doped samples were studied.We studied the preparation method of the novel photopolymer.The modification of the thermo-polymerization method was optimized by changing the preparation temperature,polymerization time and preparation of the container.The preparation steps were simplified.New THFMA/PQ/PMMA photopolymer samples were prepared by incorporating THFMA into the PQ/PMMA polymer by an optimized thermo-polymerization process.We prepared samples with different photosensitizer concentrations,THFMA concentrations and thicknesses.The new samples have the advantages of higher diffraction efficiency and faster response time.The optimum composition ratio of THFMA/PQ/PMMA photopolymer was determined by studying the holographic properties of PQ/PMMA photopolymers and THFMA/PQ/PMMA photopolymers.The diffraction efficiency of the 1.4 mm thick THFMA/PQ/PMMA sample reached 36.6% when samples were doped with 30 wt% THFMA and 1.15 wt% PQ.Doping THFMA in THFMA/PQ/PMMA polymer can improve the solubility of photosensitizer PQ,and increase the monomer concentration in the material,thereby improving the diffraction efficiency and photosensitivity.We studied the photochemical reaction principle of THFMA/PQ/PMMA photopolymer.A one-dimensional local response model was established by studying the diffusion process of the photosensitizer PQ molecules in the material.The photochemical reaction kinetics model was established by analyzing the photochemical reaction process of the material.On this basis,the two-dimensional diffusion-polymerization model was used to describe the changes of the photosensitizer PQ concentration,photoproduct concentration and refractive index modulation in the sample with the exposure time.