Preparation And Property Study Of Cable Materials Modified By Halogen-free Flame Retardants

With the development of industry, the demands of wire and cable are increasing. Most insulator and sheathe are made from organic polymers, which are easy to conflagate in heat, high pressure, a certain temperature and oxygen content. So it is necessary to improve the fire resistance of polyolefin cable materials. Halogen flame retardant which have excellent flame retardant properties. But they will release poisonous gas when the fire broke out. Accordingly, in order to meet the requirements of the environmental protection, the new type and the halogen-free flame retardant polyolefin cable materials are one of the focus reseasrches in the field of the cable.Among the halogen-free flame retardants, inorganic flame retardants, phosphorus-based flame retardants and nitrogen flame retardants have been widely used in various polymeric materials. Because they cannot produce noxious gas when burning. Polyethylene (PE), polyvinyl chloride (PVC), polypropylene (PP), ethylene-the vinyl acetate copolymer (EVA) are main in the matrix resin of polyolefin cable materials.This article study effect of synergistic additives of Magnesium hydroxide which was modified, the other flame retardants on the properties of EVA and high density polyethylene (HDPE).The properties of system were mainly researched by mechanical property, flame retardant performance,melt flow rate. And develop good halogen-free flame retardant polyolefin cable materials.There are mainly containing several parts inclouded in this research:(1)The preparation and study on the properties of modified magnesium hydroxide which flame retardant EVA.In this paper, a series of Magnesium hydroxide which include the partical size and the modification of magnesium hydroxide flame retardant EVA were studied. Magnesium hydroxide which was modified by KH550, were characterized by particle size distribution and fourier transfer infrared(FTIR) spectra. The effect of the amount, the partical size, the modification of magnesium hydroxide on the mechanical and flame retardant properties of the EVA were discussed and compared with the composites incorporated with A4085, MC328, ME.The results showed that with the increase of the flame retardant, the flame retardant properties have improved, but the mechanical properties have reduced. Filling of many magnesium hydroxide which treated by coupling agents, can lead to the rapidly increasing of the mechanical and flame retardant properties of the system. The partical size was smaller, the properties of the system were better.(2) The preparation and study on the properties of silica(SiO2) or melamine cyanurate (MCA)with Magnesium hydroxide together which treated by KH550, flame retardant EVA.In this research, silica(SiO2) or melamine cyanurate (MCA) was chosen to act as flame retardant with Magnesium hydroxide together. In addition, solubilizer of maleated ethylene vinyl acetate copolymer (MC328) were acted. The data indicated that both silica and melamine cyanurate imporved the flame retardant and mechanical properties of the system.(3) The preparation and study on the properties of Halogen-free phosphorus flame retardant with Magnesium hydroxide together which treated by KH550, flame retardant EVA/HDPE. The halogen-free phosphorous flame retardant was synthesized by the reaction of DOPO(9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide)and the bismaleimide(BMI). The halogen-free phosphorous flame retardant was characterized by fourier transfer infrared(FTIR) spectra. The system is composed by ethylene vinyl acetate copolymer (EVA) or high density polyethylene which was a matrix resin, KH550 modified magnesium hydroxide(KH550-MH) which was a main flame retardant and halogen-free phosphorous flame retardant(DB) which was a association effect flame retardant. The effects of DB, EVA, HDPE on the properties of composite materials were studied by mechanical property, melt flow rate, bibulous rate and UL-94 test. It is showed that the mechanical and flame retardant properties of the system benefit from DB. The tensile strength of system could increase tol 1.7MPa, the elongation at break raised to108%, and the flame-retardant level reached to V-0 when the mass ratio of EVA and HDPE was 36 and 9 wt.%.Comparing the comprehensive performance of each system, the date indicate that:the comprehensive was optimal when halgen-free flame retardant of ethylene-vinyl acetate copolymer (EVA) were prepared by KH550 modified magnesium hydroxide(KH550-MH2) and SiO2.The date indicated that the elongation at break raised to 168%,and the flame-retardant level reached to V-0 when the mass ratio of theKH550-MH2 and SiO2 was 47 and 8wt.%.