Synthesis Of R(MAA)₃/PMMA Composite For X-Ray Sheilding And Study Of Gel Glass

This thesis includes two parts:(1) Preparation and proerties of rare-earth/polymethyl methacrylate (PMMA) anti-radiation composites; (2) Anti-radiation inorganic composites prepared by sol-gel technology.The first part studied the preparation of anti-radiation PMMA and the relations between its structure and properties. The main results are as follows:(1) Anti-radiation rare-earth/PMMA was prepared by in-situ polymerization. The process included a first step preplolymerization and a second step bulk radical free polymerization in a mould. After polymerized MMA under 78-83℃for 20-60min first, put the prepolymerized agents into the mould for 5-7h next, and then polymerized it under higher temperature, transparent PMMA would be attained.(2)It is proved that the grain diameter of rare-earth in the composite is about 40 nm and the grain is well-distribute through TEM, transmittance, solvent resistance and Anti-radiation research of rare-earth/PMMA synthetic glass. The transmittance of these synthetic glass can all reach to 80% when the contents of rare-earth was below 20%; the solvent resistance is good because only swelling happened when put it into solvents; Shielding performance enhanced with increased the contents of rare-earth. (3) Comparing the shielding properties between lead free rare-earths glasses and lead glasses under tube voltage of 40-88kev energy shows that, ray transmittance could reach to 85% when the contents of Sm(MMA)3 below 11%; if the tube voltage is 100kVp, the lead equivalent of rare-earth can reach to 0.01025 which accord to national standard(0.01-0.04) while the number of lead glasses was 0.00945. All the results indicated lead glasses could be replaced by rare-earth glasses when the anti-radiation property was needed.In the second part, sol-gel method was applied to prepare anti-radiation gel glass. The main results are as follows:(1) the effects of acidity, solvent, water consumption, temperature on bulk glass properties were studied, formula and technological conditions were confirmed. The result shows that, the preparation of bulk glass should meet the following terms:molar ratio of H2O/TEOS is 15-24; the optimum PH is 3-4; the optimum temperature is 30℃-50℃; aging time is 30 days or longer. (2) The performance included FT-IR,XRD and transmittance of rare-earth gel glass proves the existence of silicon and gadolinium, and the transmittance is more than 70% when the contents of Gd(NO3)3 below 5%.