Preparation And Property Of Flame Retardant Wood-plastic Form-stable Polyethylene Glycol Phase Change Material

Phase change materials is a new type of energy storage materials,its application could save energy and protect the environment.However,the change of solid liquid phase will cause leakage problem of the phase change energy storage material,limiting the application of phase change materials.Scientists would solve the problem by designing the form-stable phase change materials.The way of form-stable was different,which would lead to different consequence.Due to organics have the bad characteristics of low thermal conductivity and inflammability,it make high thermal conductivity of flame retardant form-stable phase change material become intensive research.In this paper,the phase change materials were prepared by different molecular polyethylene glycol(PEG)and wood flour / polypropylene,and the suitable phase change material was PEG-6000.Then the PEG-6000 were adsorbed in the wood flour by ways of vacuum impregnation,ultrasonic impregnation,atmospheric pressure impregnation.We take advantage of wood flour with porous structure to prepare wood flour form-stable phase change material for the first form-stable.The result suggested that the vacuum impregnation makes the adsorption amount of PEG – 6000 increase by 27.5%.And the impregnation method allows the PEG-6000 to fill the porous voids of wood flour,which makes the amount of PEG-6000 in wood flour become high and the phase transition enthalpy of wood flour come up to 179.3 J/g.Different kinds of wood-plastic phase change materials were prepared by wood flour with different impregnation methods melt blending with polypropylene and coupling agent for the second form-stable.The experiment results show that the phase transition enthalpy of woodplastic form-stable phase change materials by vacuum impregnation is 39.6 J/g that increased 12.4 J/g compared with atmospheric pressure.In the material processing engineering,the loss ratio of vacuum impregnation was 10.4% lower than atmospheric impregnation.The loss ratio of phase change enthalpy of PCM with vacuum impregnation was reduced by 12.1% than that of atmospheric pressure.Scanning electron microscopy showed that the surface and interface of materials prepared by vacuum impregnation was smooth and uniform,with no prominent voids and fiber voids of wood flour.The results indicated that the hybrid packaging of the material is relatively complete,which can improve the mechanical properties and cycle performance of the material.In order to solve the deficiency of low thermal conductivity and flammability,EG was added to wood-plastic form-stable phase change materials to prepare flame retardant woodplastic form-stable phase change materials.The DSC results show that the addition of EG had no effect on the phase transition properties of materials.When EG content is 22.2 wt %,the oxygen index of material was 29.8%,the level of UL-94 was V-1,thermal conductivity increased by 109.0%.With the EG increased,the residual char content of the material was enhanced that can improve the thermal stability of the materials.Moreover,the peak of heat release rate(PHRR),the total heat release(THR),the smoke production rate(SPR)and the total smoke production(TSP)of the PCM were significantly decreased.All results implied that the flame retardant properties and thermal conductivity have significantly improved.