Studies On The Fiame Retardace Of Magnesium Hydroxide And It's Synergistic Additives On LDPE

Due to the expand of the fields in applied materials and the requirement of human being's living surroundings, the researches on the non-halogen flame retardants (FR) have become the research focus. Magnesium hydrogen is a type of excellent inorganic flame retardant with eminent fire retardance and smoke suppressant, which has been attached more and more importance since 70s. At the end of 20 century, with the successful development of nano-meter Mg(OH)2 which has special uses applied in the materials of electronic equipments, light cable communication and so on, the new type of non-halogen FRs have an unlimited future. At the same time, the applied fields of magnesium hydrogen will become more extensive with the successful development of the FR synergic additives.The flame retardance of magnesium hydrogen and it's synergic additives on LDPE has been mainly studied, and the flame retardant mechanism has been researched as well. Firstly, we choose titanate coupling agent as the surface modifying agent of the micro-meter magnesium hydrogen. Some comparative researches were done after the two types of Mg(OH)2 (nano-meter Mg(OH)2 and micro-meter Mg(OH)2) were filled in LDPE, we finally chose nano-meter Mg(OH)2 as the main FR. The effects of synergistic flame retardants to nano-meter Mg(OH)2 that synergistic agents made including red phosphorus, zinc borate and graphite have been studied, and it was found the best dosage that red phosphorus and zinc borate synergized nano-meter Mg(OH)2. At the same time, the mechanics performance and the flame retardance of a series of samples filled with the best formula have been studied. The tensile ratio of the system has been improved through increasing the content of EVA and decreasing the content of nano-meter Mg(OH)2. The mechanism of the complex flame retardant system has been primary investigated through studying the weight of the coke of the complex system of Mg(OH)2/Al(OH)3. It is found that nano-meter Mg(OH)2 can promote to form carbonization on the surface of the resin and form a cover layer which can improve the flame retardance of the resin. Through the research on the curve of TG-DTA of the complex system, it is found that the mainly synergistic mechanism of red phosphorus is that red phosphorus turn into phosphoric acid and phosphorate by heat, and phosphorate change into poly-phosphorate which is a dehydration agent. So poly-phosphorate synergize Mg(OH)2 through accelerating the decompose of Mg(OH)2.