| It is researched that the environmental aging mechanism of a Styrene Ethylene Butylene Styrene (SEBS for short) colloid material for the civil aircraft in the future. According to the typical airport environment, the main experiments are made up of the ultraviolet(UV for short) light accelerated aging test and the hot air accelerated aging test in four temperature conditions of 30℃、40℃、50℃、70℃, which analyzes the influence of the mechanical properties and surface properties by the UV radiation and temperature working, taking the sample bearing capacity and the morphology characteristics of the surface macroscopic and meso as the main test indices. Different stage samples are analyzed by the Fourier Transform Infrared Spectrometer(FTIR for short), in order to research the influence on the chemical structure. New samples tested by the Differential Scanning Calorimetry (DSC for short) and the Thermal Gravimetric Analyzer (TG for short), to obtain the glass transition temperature and the weight loss temperature of the SEBS colloid material. A theoretical prediction of service life for different temperatures was proposed by the dynamic curve linearization method. The main studies and conclusions are listed as follo wings:(1) The accelerated aging test of the UV light about the SEBS colloid material shows that the material bearing capacity takes a few increasing trend in UV irradiation for a short time when the after-cure of the material can be promoted; however, the long time testing makes surface viscous at the macro level that increases the sample pollution by solid particles or dust, and also finds the aging induration condition at the meso level, which leads to the mechanical properties decreased.(2) The results of accelerated aging test in the temperature conditions shows that the main reason of influencing the material bearing capacity is the sample pollution by solid particles or dust in a low temperature environment such as 30℃ and 40℃; As UV testing, the time required for further curing reduces gradually with the temperature increasing, there is a certain increase about the material bearing capacity in a short time, and also take reducing with a long time; the edge of the sample serious warping phenomenon in the higher temperature environment such as 70℃ is the main reason of influencing the material bearing capacity.(3) Different stage samples analyze by the FTIR shows that the chemical structure of the SEBS colloid material is stable for the test condition, and the SEBS colloid material could be well used in the normal working environment of the civil aviation aircraft.(4) New SEBS colloid material takes in the DSC and the TG. The glass transition temperature and the weight loss temperature is respectively 168℃ and 190℃, which is much higher than the normal airport temperature and the crosslinking reaction and the decomposition reaction will not happen.(5) A theoretical prediction of service life for different temperatures was proposed by the dynamic curve linearization method. The result of prediction is 221 days corresponding to the room temperature 20℃ at the highest test temperature 70℃, taking the sample bearing capacity as the evaluating indicator, which satisfies the requirement of the design.The analysis of the environmental aging properties of the SEBS colloid material applies the aging test method of the UV light and the hot air, combining with mechanical properties testing, morphology characteristics of the macroscopic and meso, chemical structure analysis, thermal performance analysis and theoretical life prediction, which is a comprehensive analysis and obtains the reasonable result. This process is reliable and efficient, and also can be widely used in the aging analysis of other polymer material. |
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