In order to obtain the coating with low water absorption and fire retardant,phosphorus-containing benzoxazine was synthesized and used in UV-LED curable epoxy acrylate coating with LED-385 nm as the light source.The flame retardancy,adhesion,pencil hardness,acid/alkali resistance and water resistance of the coating were studied.To reduce the amount of phosphorus in the fire retardant coating and maintained the flame retardancy,dopamine hydrochloride was introduced into the above system and the synergistic effect of phosphorus and nitrogen on the performance of the coating was explored.The results showed that among the two phosphorus-containing benzoxazine derivatives(DPOBH and DOPOBH),DPOBH exhibited better promotional effects on the flame retardancy,adhesion and hardness of the coatings than DOPOBH.The coating with 3.7%DPOBH(EA/DPOBH3.7)exhibited a UL-94 fire retardant rating of V-0 level,a hardness of B grade,an adhesion of 1 grade,an acid mass loss of only 0.40%,an alkali mass loss of 2.13%,and a water absorption of only 0.82%.On this basis,the synergetic effect of phosphorus and nitrogen on the properties of coatings was explored.The results showed that the UL-94 flame retardant rating of V-0 was gained with by adding 0.5%dopamine hydrochloride(EA/DPOBH3.5-N0.5).The hardness of 2H,the adhesion of 1,and improved acid/alkali resistance are obtained with EA/DPOBH3.5-N0.5.In conclusion,phosphorus-containing benzoxazine could effectively improve the flame retardancy and acid/alkali resistance and reduce water absorption of epoxy acrylate coating.
关键词
防火涂层/环氧丙烯酸酯/苯并噁嗪/光固化/磷氮协同作用
Key words
fire retardant coating/epoxy resin/benzoxazine/UV-LED curable/synergistic effects of phosphorus and nitrogen