| Polycarbonate(PC)is prone to environmental stress cracking(ESC)in the process of using which will affect the reliability of products.Coating technology is one of the effective ways to improve ESC resistance of PC products.Researching the influence rule of coating system structural performance evolution on the behavior of ESC which was induced by using environment has a great significance understand the aging failure behavior of PC/coating transparent parts and improve the safety and service life of the products.This article focuses on the influence of the ratio of silicone hybrid coating(hereinafter referred to as Silicone)and UV aging on the structural properties and evolution of PC/Silicone coating systems.The ESC behavior such as stress relaxation rate and crack morphology under the joint action of solvent and stress was studied on this basis and the anti UV aging and ESC properties of the PC/Silicone coating system after the introduction of UV absorbents in the coating are also explored.The main work includes:(1)The study involves the influence mechanism of the content of inorganic component in silicone coating on the ESC behavior of PC/Silicone system.The results show that: The resistance of the PC/Silicone system to ESC increases in line with the increase of the content of inorganic components,which is due to dense cross-linked network formed between inorganic and organic components,and with the increase of the content of inorganic components,with coating being denser satisfactory effect increases accordingly on solvent coating.On the premise of good mechanical matching of the membrane base,the ESC resistance of PC/Silicone system was improved.(2)The structural properties evolution and ESC behavior of the PC/Silicone system after undergoing UV aging were investigated.The results showed that the ESC protection performance of the coating has a certain aging property under UV aging and the protective effect of the coating decreases with the aging time,which mainly due to the degradation of PC matrix and the decrease of the adhesion properties of the substrate under UV irradiation,resulting in the decrease of the ESC resistance of the products.After aging for a certain time,the coating was cracked leading to loss the solvent barrier and the protective effect of ESC.(3)The effects of UV absorbents on the resistance to UV aging and ESC behavior of PC/Silicone system were investigated in this paper.The results show that the introduction of ultraviolet absorbent coatings enhance the protective effect of optical coating on PC substrate,delay the membrane adhesion's failure,ensure the integrity of the coating after UV aging.The performance of the PC/Silicone system under the action of solvent stress and ESC was maintained after UV aging. |
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