年产1200吨增韧环氧树脂配方及车间工艺设计(2)
根据设计任务书所下达的任务，顺利完成对聚氨酯改性环氧树脂车间工艺的设计。在整个设计过程中，对聚氨酯预聚体生产以及其与环氧树脂复合的流程有一个全面的认识，并根据所学的专业知识，结合自己在认知实习中的经验，灵活应用，为今后从事相关的生产管理工作打下了一定的基础。
由于聚氨酯改性环氧树脂车间工艺设计的知识面很广，而我的知识和经验有限，设计错误和不妥之处，恳请批阅老师批评指正。
Illustration
Epoxy is a very important varieties of thermosetting resins. It has excellent mechanical properties, electrical insulation properties, corrosion-resistant chemical, and heat-resistant adhesive properties. However, epoxy resin still exist deficiency in toughness, so it needs to be modified to enhance its toughness. In this design, epoxy resin is modified by polyurethane to enhance the toughness, because polyurethane has a flexible macromolecular chains, high flexibility and good resistance of abrasion vibration. Being modified epoxy can obtain high performance epoxy resin matrix, and the most commonly used method of toughening epoxy resin is to use elasticity to modify. Therefore, the design uses polyurethane as the toughening of epoxy resin, in the mean time, the introduction of polyurethane also makes the strength of the system greatly improved.
According to the task, an annual output of 1200 tons of the polyurethane-modified epoxy resin workshop is designed in this task. Through access to a large number of literature and cognitive training, the production technology of polyurethane-modified epoxy resin and production equipment are scientific proofed and designed.
For the technical requirements of the production of polyurethane-modified epoxy resin, the design in accordance with the polyurethane-modified epoxy resin enterprise quality standards, the corresponding formulation and production process are selected.
According to the results of experiments, with the changes in mass ratio of two components, epoxy resin and polyurethane, hardness, tensile properties, impact properties, elongation at break, vicat softening point and glass transition temperature of polyurethane-modified epoxy resin have changed. With increase of the addition of polyurethane, the tensile strength increases, but after the additon of polyurethane is greater than 20%, tensile strength decreased sharply, which shows that the best performance is 80/20. Therefore, in this design, the mass ratio of epoxy resin and polyurethane prepolymer selects 80/20. The mass ratio of polyurethane and epoxy resin prepolymer is 1:4. The method of synthesis of polyurethane prepolymer:, the prepolymer method (two-step), semi-prepolymer method, the general now in an enterprise to one-step, two-step oriented. The selection of the design synthesis is one-step, one step is that polyether binary alcohol and TDI (toluene diisocyanate) make synthesis in organic tin catalyst. The compositon of polyurethane and epoxy resin are reactive and non-reactive, The selection of the design is reactive approach. By reactive approach, it can strengthen two components and enhance the modification effect.
In this design, the production process to determine the product is dehydration, the synthesis of polyurethane prepolymer, the composition of polyurethane prepolymers and EP, dilution and deaeration. In the dehydration process, the temperature needs to be heated to 120 ℃;the time is at 1 hour;the vacuum pressure is -0.1MPa; and the water content after dehydration is about 0.07%; in the synthesis of polyether diols and TDI, the temperature needs to be heated to 80 ℃, and it has been maintained the reaction temperature for two hours; in the composion process of polyurethane prepolymer and epoxy resin, the temperature is controlled at 80 ℃, and the time is controlled in 1 hour; in the dilution process, the temperature needs to be at 60 ℃, and time is controlled in half an hour; in the deaeration process, the time is 30 minutes, and the vacuum pressure is reduced to -0.07MPa.
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