| As known,attributed to the similar chemical structure,isoprene rubber(IR)is the most ideal substitute for natural rubber(NR),which is of great importance for aviation tires owing to its excellent comprehensive performance.However,there are still some differences between IR and NR in processing performance and mechanical properties.In this thesis,the kilograms silica/IR wet masterbatch with good processing performance and mechanical properties which could match NR was obtained through the developed wet mixing technology of silica/IR.It is confirmed that the application of silica/IR wet masterbatch in the aircraft tire parts is feasible,through comparing the performance differences between the wet masterbatch and the key parts of the aircraft tire,and the method for determination of curing parameters of the tire is given in combination with the influencing factors of the properties of the aviation parts.The thesis mainly focuses on the following aspects:1.Development of silica/IR wet mixing technology.The in-situ modification of polar silica with TESPT in non-polar solvent N-hexane by strong shear force was found and the optimize parameters of silica suspension preparation technology were determined by orthogonal experiment.The final devolatilization method of the mixture was determined combined with the industrial production process of IR,and the kilograms wet masterbatch was obtained,where the silica dispersion grade could reach the highest level of 10 through the testing of the authoritative testing organization.2.Feasibility analysis on application of silica/IR wet masterbatch in aviation tire part compound.Firstly,the properties of silica/IR wet and dry mixing composite,and silica/NR dry mixing composite were compared.The results showed that compared with dry mixing,silica/IR wet mixing composite not only had a shortened mixing time,but also has better mechanical properties than silica/IR dry mixing composite,and possessed the same properties as silica/NR dry mixing composite.The results of TEM showed that the aggregation size of silica in wet masterbatch was about 100nm,which was obviously lower than that in dry one(1 μm).The improvement of the silica distribution made up the gap between IR and NR,and exhibited almost the same performance with NR dry mixing composite.Then,the carbon black with the best comprehensive performance was selected out and compounded with the wet masterbatch with different silica filling amount.The optimum filling amount of silica and carbon black was 20 phr and 30 phr,respectively.Finally,the wet masterbatch was used to replace the rubber of many parts of the aircraft tire,and it was found that the wet masterbatch was the most promising matrix compound for the aircraft tire.3.Optimization of vulcanization process of aviation tire.It was concluded that low temperature and long vulcanization time could improve the properties of the formula through discussing the effects of three factors on the properties of the vulcanizate in detail.In combination with the deformation of tire in actual use,the stress at definite elongation of vulcanized rubber within 100%strain was quantitatively calculated by using the torque value of rubber processing analyzer.It was found that the relative error between the measured value and the calculated value was very small.When applied to the real tires,what’s more,the performance of the rubber with 20 min shortened curing time could be improved significantly. |
