Study On Retardant Insulation Materials Prepared By Waste Polyester Flame

Due to the excellent physical and chemical properties,polyethylene terephthalate(PET)has been applied in life and industry widely.However,PET is difficult to be degraded and then may cause environmental pollution and resource waste.To deal with this problem,PET can be degraded to obtain bis-hydroxyethyl methacrylate(BHET),which can be used as polyhydric alcohols to prepare polyurethane(PU),a thermal insulation material.In this thesis,the hydrotalcite-like compounds(HTLCs)was prepared by using the solid waste from thermal power plant.Then,the catalyst for degradation of PET was prepared based on the HTLCs.The influence factors for PET degradation have been discussed.Finaly,the recycled PU was synthesized by BHET and the flame retardancy and smoke suppression of PU have been studied.(1)The HTLCs and catalyst for degradation of PET were prepared using the magnesium oxide flue gas desulfurization residue(MFGDR)as raw materials.The structure of products was tested by X-ray diffraction(XRD)technology.The specific surface area of catalyst was measured by a Brunner-Emmet-Teller(BET)method.The main product of PET alcoholysis,BHET was characterized and determined by differential scanning calorimetry(DSC),thermogravimetry(TG),infrared(IR),mass spectrometry(MS),scanning electron microscope(SEM)and nuclear magnetic resonance(~1H-NMR)methods.The optimum experimental conditions were that: the calcination temperature was of 500?,the EG-to-PET ratio was 5:1,the usage of catalyst in degradation of waste polyester was 2 wt% and the alcoholysis temperature was 198?.As a result,the yield of BHET could reach 69.34%.The catalysts were easy to be separated in the system.The yield of BHET could reach 47.59% after it had been reused for five times.(2)HTLCs exhibited certain flame retardancy and smoke suppression performance for PU,especially,it showed a good flame retarding synergist effect with ammonium polyphosphate(APP).The limiting oxygen index(LOI)of the system of APP(25.8%)/ HTLCs(6.4%)/PU(67.8%)could reached 34.5%,and the maximum heat release rate reduced from140.3005 kW/m~2(pure PU)to 85.1680 kW/m~2,a decline of 39.30%;the maximum smoke release rate reduced from 0.5677m~2/s(pure PU)to 0.1810m~2/s,a drop of 68.12%.The system of APP(15.4%)/ HTLCs(3.8%)/PU(80.8%)in PU has good mechanical,thermal insulation and fire-retardant performance with the compressive strength of up to 1.02 MPa,a thermal conductivity of 0.028 W/(m·K)and the LOI of 31.33%.The improvement in flame retardancy and smoke suppression performance for polyurethane is attributed to the interaction between APP and HTLCs and form a dense and tough carbon layer.So,there are both the gas phase and the condensed phase flame-retardant mechanism in this system.(3)The recycled Polyurethane(RPU)was successfully prepared by BHET instead of polyether polyol.The system of APP(12.7%)/ HTLCs(3.2%)/RPU(84.1%)in RPU has a good overall performance with the compressive strength of 0.93 MPa,a thermal conductivity of 0.027W/(m·K)and LOI of 27.63%.