| Ethylene-acrylate copolymers have good flexibility and processing performance, widely used in seals, packaging films, tubes and wire. But the flammable and easy dripping properties of the materials hinder application in some areas. Thus the researches about increasing the flame retardant and anti-drip properties of ethylene-acrylate copolymers are important. In this paper, based on the structural characteristics of ethylene-acrylate copolymerethylene acrylate copolymer structural characteristics, using UV cross-linking technology and calcium carbonate (CaCO3) and organic silicon acrylic polymer flame retardant system constructed to carry out the expansion of ethylene-acrylate copolymer halogen flame retardant and cross-linking studies.Calcium carbonate (CaCO3) and silicone (methyl vinyl silicone rubber (VMQ) or methyl silicone resin (MQ)) were added to the ethylene-butyl acrylate copolymer (EBA) in order to get the retardant material of EBA. Based upon the results of limiting oxygen index (LOI) and anti-droplet tests, CaCO3/silicone-EBA has good flame retardant and anti-drip properties. The thermal degradation of EBA was assessed by thermogravimetric analysis (TGA). TGA data revealed that CaO3/silicone could improve the fastest thermal decomposition temperature of EBA, especially, CaCO3/VMQ effectively promoted the charring, improving the flame retardant of the system. X-ray photoelectron spectroscopy (XPS) analysis, studying the reasons of VMQ with the better synergistic flame retardant capacity, of silicon enrichments on the surface of flame retardant system results showed enrichment capacity of VMQ was superior, which increased the probability of forming char, at the about end of thermal degradation of EBA, leading to VMQ with enhanced synergistic flame retardant effect.Ultraviolet induced cross-linked of EBA were explored in presence of benzophenone(BP) as photoinitiator, the content of gel in cross-linked system measured by Soxhlet extraction method, on which the basis of found the best optimal crosslinking conditions. The results showed that EBA could photocrosslink with the help of BP, the content of gel got75.91%, at the optimum parameters. The UV cross-linking influences for thermal decomposition process were investigated by TGA-GC/MS. The TGA-GC/MS showed the UV cross-linking could improve the thermostability of EBA in a certain thermal degradation process, with the changes of the thermal degradation processes. The mechanism of UV cross-linking was studied by FTIR and GPC, which may be the process:decomposition reaction simultaneously occurred in the course of the UV irradiation crosslinking of EBA, and the cross-linking points and decomposition points are the same, the a-C attached to the carbonyl group. The ester group of EBA decomposed to carboxylic acid that can be further decomposed into hydrocarbons. The CaCO3/MQ/EBA crosslinking flame retardant system was prepared by UV cross-linking method. The content of the gel was tested by Soxhlet extraction,in this flame retardant system. The results showed that:calcium carbonate/methyl silicone resin/EBA may be UV cross-linked by photoinitiator and the content of gel was less than crosslinking the EBA. The impact of the UV cross-linking for anti-dripping in the anti-flame retardant system was evaluated by the anti-dripping test, which was that the UV cross-linking can improve the ability of anti-dripping in the flame retardant system. By TGA-FTIR hyphenated techniques to study the influences of UV crosslinking behavior about the thermal degradation for CaCO3/MQ/EBA impact flame retardant system, the experimental results showed that:UV cross-linking could improve the capability of charring, reduce the content of the Ester, thereby reduced the volatilization contents of CO2in the thermal degradation process, and increased the amount of small molecule volatile hydrocarbons. |
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