Preparation of UV Curable Waterborne Polyurethane and its Application in Coatings

Waterborne UV curable polyurethane emulision containing C=C bond was prepared with self-emulsification. 3% water soluble photoinitiator was added to the polyurethane emulision, and polyurethane films was prepared by ultraviolet irradiation. The structure of the polyurethane emulision and films were confirmed by means of Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and thermogravimetric analysis. FTIR test result shows that cross linking and solidification reaction of C=C double bond happened after UV irradiation. When C=C content increases, the particle size of polyurethane emulision increases, crosslinking degree of films increases, water resistance and heat resistance have both been improved. When C=C content is 8.51%, gel content is more than 90% and the lowest water absorption can be 12.5%.

Kinetic Models of Integrated Solidification and Cementation of Cementformation Interface with New Method

The isolation failure of cement-formation interface is an important and urgent problem in oil production, while an effective way to solve it is to realize the integrated solidification and cementation of cement-formation interface (ISCCFI). In order to study the kinetics of ISCCFI with MTA (Mud Cake to Agglomerated Cake) method, the Diamond Differential Scanning Calorimetry Analyzer is adopted for experiments with dynamic method and isothermal method. The results show that there is a linear relationship between the solidification reaction temperature and the heating rate of ISCCFI with MTA method. For the first exothermic peak, the initial temperature, peak tip temperature and final temperature are 53 °C, 69 °C and 83 °C respectively, and the apparent activation energy of solidification reaction is 44.39×10-3 kJ.;mol-1, the natural logarithm of preexponential factor is 7.26, the solidification reaction order is 0.88. For the second exothermic peak, the initial temperature, peak tip temperature and final temperature are 83 °C, 92 °C and 114 °C respectively, and the apparent activation energy of solidification reaction is 99.14×10-3 kJ.;mol-1, the natural logarithm of preexponential factor is 24.77, the solidification reaction order is 0.94. The maximum solidification reaction rates at 50 °C, 75 °C and 90 °C are 0.09×10-3 s-1, 0.27×10-3 s-1 and 0.51×10-3 s-1 respectively. The kinetic models of ISCCFI with MTA method under different temperatures are established. It provides a theoretical and technical support for the isolation improvement of cement-formation interface.

Preparation of Epoxy Modified Organosilicone High-Temperature Resistance Coatings

An ambient-cured organosilicone resin modified with epoxy resin was synthesized with lab-synthesized polysiloxane resin and biphenix-A epoxy resin(E-20) by copolymerization at 180~190 °C for 2~3 hours. The effect of ratios between polysiloxane resin and E-20, reaction temperatures and reaction time on heat resistance and miscibility etc were discussed in detail. The experiment results showed that the epoxy modified organosilicone resin exhibited the best solubility performance and adhesion strength when the ratio of the polysiloxane resin to E-20 was 3:7. The Fourier transform infrared spectra (FTIR) revealed that hydroxy on epoxy resin had reacted with ethyoxyl on organic silicon molecular chain, but no ring-opening reaction happened on epoxy group of E-20. The excellent high-temperature resistance painting, based on these epoxy modified organosilicone resin was prepared with flake aluminum powder as temperature resistance filler, polyamide 650 as curer and WD-50 coupling agent as curing-promoter. It was shown that the temperature resistance was superior to 600°C and the adhesion strength of the coating was up to 1 grade. Scanning electron microscope(SEM) revealed the reaction happened on -Si-O-Si- and Al under high temperature improved the coatings to resist higher temperature. The mechanism of the high-temperature anticorrosion is attributed to “ring-opening reaction” and “cross-link solidification reaction”.

Leaching Studies of Cement-Glass Package Containing Sodium Borate

A new solidification technique using cement-glass, which is a mixture of sodium silicate, cement, additives, and initiator of the solidification reaction, was developed for sodium borate liquid waste generated from pressurized water reactor (PWR) plants. The cement-glass could solidify eight times as much sodium borate as cement could, because the solidifying reaction of the cement-glass is not hindered by borate ions.The reaction mechanism of sodium silicate and phosphoric silicate (initiator), the main components of cement-glass, was studied through X-ray diffraction and compressive strength measurements. It was found that three- dimensionally bonded silicon dioxide was produced by polymerization of the two silicates. The leaching ratio of cesium from the cement-glass package was one-tenth that of the cement one. This low value was attributed to a high cesium adsorption ability of the cement-glass and it could be theoretically predicted accordingly.