Optimum compatibilization for the nonflammability of thermoplasticized crosslinked polyethylene/metal hydroxides composites with a compatibilizer

Nonflammability of the thermoplasticized crosslinked polyethylene (PE)/polyolefin elastomer (POE)/metal hydroxide flame retardant/compatibilizer composites were investigated. The thermoplasticized crosslinked PE was decrosslinked from the crosslinked high-density PE under the supercritical methanol condition. Two types of metal hydroxides: aluminum hydroxide (AH) and magnesium hydroxide (MH), and a low-density polyethylene-g-maleic anhydride (LM) were used as flame retardants and a compatibilizer, respectively. Nonflammability of both PE/POE/AH/LM and PE/POE/MH/LM composites was enhanced with metal hydroxide flame retardant concentration. PE/POE/MH/LM composites had better nonflammability than PE/POE/AH/LM composites at the same flame retardant concentration. Interestingly, nonflammability of the composites was also strongly influenced by the compatibilizer concentration. At low compatibilizer concentration, the nonflammability of the PE/POE/MH/LM composites was improved with the compatibilizer concentration. In contrast, at high compatibilizer concentration, the nonflammability of the PE/POE/MH/LM composites was deteriorated with the compatibilizer concentration. This demonstrates that optimum concentration of the compatibilizer can help to enhance the efficiency of the flame retardants in the development of the nonflammable polyolefin for the wire and cable industry.