Research On The Preparation, Flame Retardancy And Application Of Calcium Alginate/nano-calcium Borate Composite Materials

At present,a single material is difficult to meet the requirements of many fields because of its simplex performance.Therefore,composites have attracted much attention due to their advantages in combining different materials,especially nano-inorganic materials and organic polymers.The cross-fusion between materials is also receiving more and more attention from researchers.As the flame retardant with broad application prospects,there is an urgent need to develop toward composite materials.Calcium alginate is formed by cross-linking sodium alginate and calcium chloride.It has a wide range of raw materials and inherently flame retardant.It is a highly efficient,green,and degradable flame retardant.To further increase the resistance of calcium alginate,reducing the cost of use,and promoting its application in production and life we have introduced calcium borate,.In this paper,sodium alginate?SA?and borax were used as raw materials to synthesize calcium alginate/nano-calcium borate?CAB?composite by the in situ method.In the first part,due to synthesis the nano-borate particles orthogonal experiments were designed according to CaCl₂ concentration,calcium alginate and borax mass,pH and other experimental conditions.In the second part,the prepared CAB was tested for flame retardancy properties.The study found that the composite material had a limiting oxygen index?LOI?of>60%,far exceeding the LOI value of pure calcium alginate?CA??48%?.It is V-0 rated in the vertical burning test?UL-94?.And when the combustion behavior was tested in a cone calorimetry?CONE?experiment,it exhibited excellent flame retardant properties.According to the results of thermogravimetric analysis?TG?,the thermal stability is also greatly improved.It can be seen that the flame retardant prepared by the combination of calcium alginate and calcium borate has excellent performance in terms of flame retardancy and thermal stability.In general,the calcium nanoborate particles carry a certain amount of crystal water.Forthe gas phase mechanism,the crystal water volatilizes and cooling the temperature around material,and for the solid phase aspect,the calcium borate is gradually melted to produce the glassy substance under high temperature conditions.A that covers the surface of CA to prevent it from coming into contact with oxygen and heat,thereby inhibiting the decomposition of combustion of CA.Finally,the pyrolysis gas product was tested by gas chromatography-mass spectrometry?Py-GC-MS?to predict its decomposition mechanism and the effect of calcium borate.In the third part,in order to put the prepared composite materials into practical production applications,We chose a secondary compound of polyester and CAB to impart flame retardant properties.Polyester fabric is widely used in clothing,interior decoration and so on.,but it does not possess the property of flame retardancy,and it is prone to droplets during combustion.Therefore,in this experiment,the composite material is applied to the polyester fabric through a simple coating process and post-crosslinking method,and the polyester fabric is required to impart good flame retardancy and drip resistance to improve the safety of use.After scanning electron microscopy?SEM?,Fourier transform infrared spectroscopy?FTIR?,X-ray diffraction?XRD?,LOI,UL-94,CONE and other experiments,The combustion behavior was tested.It was found through analysis of the experimental results that the treated polyester fabric had good flame retardant properties and resistance to droplets.The analytical results show that the treated polyester fabric has good flame retardant properties and is resistant to dripping.Finally,the pyrolysis mechanism was derived by Py-GC-MS test.