| Today,with the rapid development of China,the demand for communication,electric power and other construction fields is increasing,which makes people pay more attention to the wires and cables used to protect communication transmission.Due to the complex and diverse working environment of wire and cable,wire and cable materials can easily cause fires,causing economic losses and casualties to society and individuals.Therefore,people’s research on the flame retardancy of wire and cable materials is getting deeper and deeper.Attapulgite is a natural and environmentally friendly nano-material.Because of its unique rod-like fiber structure,attapulgite has excellent adsorption and heat resistance.Zirconium phosphate is a two-dimensional layered compound,which is used in flame retardant polymers because of its rich surface reaction sites,barrier and catalytic carbonization.In this paper,zirconium phosphate was loaded on attapulgite,and the prepared composite powder was added to wire and cable materials to study its flame retardant properties.The main experimental research of this paper is as follows:1.Attapulgite and commercially available zirconium phosphate were mixed in proportion by physical blending method to prepare attapulgite/zirconium phosphate composite powder.After the composite powder was added to halogen-free low-smoke cable materials,the mechanical properties of the composite materials were improved,and the elongation at break was increased by 14.56% at the maximum.Moreover,the composite powder can improve the smoke density and flame retardancy of the composites to varying degrees.The peak heat release rate,average heat release rate and total heat release rate of the composites are reduced by 5.00%,9.14% and 13.45%respectively.When the composite ratio of attapulgite and zirconium phosphate is 3 : 2,the maximum smoke generation can be reduced by 5.66%.From the comprehensive comparison of the properties of the composites,the optimum ratio of attapulgite to zirconium phosphate is 3 : 2.After that,the best ratio was further processed to study the influence of the composite powder with different particle sizes on the properties of halogen-free low-smoke cable materials.When the composite powder is ball milled for 40 min,the particle size of the composite powder is the smallest,the oil absorption value is the highest,and the mechanical properties,smoke density and flame retardancy of halogen-free low-smoke cable materials are greatly reduced.2.Based on the above experimental research,the best compound ratio and treatment method of attapulgite and zirconium phosphate composite powder were explored.On this basis,zirconium phosphate synthesized by oxalic acid method was chemically synthesized on attapulgite pretreated in different ways and applied to halogen-free low-smoke cable materials.The experimental results show that the composite powder prepared by grafting zirconium phosphate onto attapulgite treated by cell pulverizer has the highest mechanical properties,the least smoke emission in smoke density performance,and the time to reach the maximum smoke emission is relatively long,and the average heat release rate,peak heat release rate and total heat release rate are also the best in the same group.3.Through the above experiments,the best pretreatment method of attapulgite,the best compound ratio of composite powder,the best treatment method and time of composite powder were obtained.Based on this,zirconium phosphate was synthesized on the surface of attapulgite by hydrothermal method and applied to halogen-free low-smoke cable materials.The experimental results show that zirconium phosphate synthesized by hydrothermal method by grafting attapulgite can greatly improve the mechanical properties of the composites,with the tensile strength and elongation at break increasing by 9.24% and 16.45%,the oxygen index increasing by 3.95%,the smoke emission decreasing by 3.94%,and the average heat release rate,peak heat release rate and total exposure rate decreasing by 6.29% and 11.1%respectively. |
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