Simultaneously Improving Flame Retardant Performance, Thermal Stability and Conductivity of Copolymers of Polyethylene‐octene by Addition of a Ternary Composite Flame Retardant System

Abstract

The development of high efficiency and low‐cost refractories has always been a subject that attract people‘s attention. Although polyethylene‐octene copolymers (POE) has excellent mechanical properties, it is easy to be ignited, which seriously hinders its multi‐field applications. In this paper, a novel ternary composite flame retardant system, ammonium polyphosphate (APP)/expanded graphite (EG)/sepiolite (SEP), was proposed and applied to POE to prepare high flame‐retardant POE composites. The experimental results showed that the addition of SEP could play a good reinforcing role, so as to improve the mechanical properties of POE/APP composites. Thermogravimetric analysis (TGA) showed that when the ratio of EG and SEP was 1 : 1, the initial thermal decomposition temperature decreased significantly, which was conducive to the early degradation and carbonization of POE/APP composites. The thermal conductivity test showed that the addition of SEP can reduce the thermal conductivity of POE/APP composites. In addition, the flame retardant test results revealed that when the ratio of EG and SEP was 1 : 1, the oxygen index (LOI) increased to 25.3 %, the heat release rate (HRR) decreased to 140 kW/m2, the total heat release (THR) decreased to 70 MJ/m2, and the carbon layer produced by combustion was dense and uniform, which contribute to the great heat insulation. In conclusion, the addition of an appropriate amount of ternary compound flame retardant (EG/SEP/APP) could have an excellent synergistic flame retardant effect on POE/APP composites, and the processing method was simple and efficient, which would benefit to broad application of the prepared POE composites.

Remarkable effects of silicone rubber on flame retardant property and mechanical properties of crosslinked high‐density polyethylene/bio‐based magnesium phosphate flame retardant (MHPA) composite

“…This may be because the network structure formed after the increase of SR content is more stable and not easy to break. [ 20 ] Figure 3C shows the hardness change of HDPE composite. It can be seen from the figure that a small amount of SR can improve the hardness, while too much SR will weaken the hardness.…”

Development of bio‐based magnesium phosphate flame retardant for simultaneously improved flame retardancy, smoke suppression and mechanical properties of HDPE

“…3 The flame retardancy and smoke suppression of MH are mainly attributed to the following two factors: (1) the water vapor phase generated during the dilution and decomposition of combustible gas in the gas, and (2) the stage in the decomposition process of forming a physical barrier composed of MgO in the condensate. 4,5 However, the interfacial adhesion between inorganic flame retardants such as metal hydroxide and polymer matrix is poor. This leads to severe aggregation of inorganic substances and poor dispersion in the polymer matrix, which worsens their mechanical properties.…”

“…With the growth of the global economy, magnesium hydroxide (MH), as a non‐toxic and smokeless flame retardant, has attracted much attention due to the environmental concern 3 . The flame retardancy and smoke suppression of MH are mainly attributed to the following two factors: (1) the water vapor phase generated during the dilution and decomposition of combustible gas in the gas, and (2) the stage in the decomposition process of forming a physical barrier composed of MgO in the condensate 4,5 . However, the interfacial adhesion between inorganic flame retardants such as metal hydroxide and polymer matrix is poor.…”

Flame Retardancy and Smoke Suppression of Silicone Rubber Foam with Microencapsulated Sepiolite and Zinc Borate

“…SEP and metal-organic framework were introduced into thermoplastic polyurethane and found the HRR and total heat release (THR) of the composite could be reduced by 78.9% and 39.1%, respectively [29]. SEP/APP/EG flame retardant was introduced into polyethylene octene copolymer, and the experimental results showed that the LOI value could reach 25.3%, and the THR was reduced to 70 MJ/m 2 [30]. Polypropylene (PP) with 0.5 wt% premodified SEP and 12 wt% commercial intumescent flame retardant could reach UL-94 V-0 classification and effectively improve the flame retardancy and smoke suppression of PP [31].…”