摘要
To improve the flame-retardant efficiency and water resistance of ammonium polyphosphate（APP）, the UV-curable pentaerythritol triacrylate（PETA） was used to microencapsulate APP via the UV curing polymerization method. The prepared PETA-microencapsulated APP（PETA-APP） was characterized by Fourier transform infrared spectroscopy（FTIR）, scanning electron microscopy（SEM）, and thermogravimetric（TG） analysis. PETA-APP was used as intumescent flame retardant（IFR） alone to flame retard polypropylene（PP）. The water resistance of PP/PETA-APP composites was investigated, and the effect of PETA on the combustion behaviors of PP/APP composites was studied through limiting oxygen index（LOI）, vertical burning test（UL-94） and cone calorimeter（CC） test, respectively. With 40 wt% of PETA-APP, the PP/PETA-APP system could achieve a LOI value of 30.0% and UL-94 V-0 rating after treatment in hot water for 168 h, while the LOI value of the system containing 40 wt% uncoated APP was only 19.2%, and it failed to pass the UL-94 rating. CC test results showed that the heat release rate（HRR）, mass loss rate（MLR） and smoke production rate（SPR） of PP/PETAAPP system decreased significantly compared with PP/APP system, especially the peak of HRR was decreased by 51.4%. The mechanism for the improvement of flame reatardancy for PP/PETA-APP composites was discussed based on FTIR and X-ray photoelectron spectroscopy（XPS） tests. All these results illustrated that simultaneous improvement of flame retardancy and water resistance for PP/APP was achieved through coating UV-curable PETA onto APP.
To improve the flame-retardant efficiency and water resistance of ammonium polyphosphate（APP）, the UV-curable pentaerythritol triacrylate（PETA） was used to microencapsulate APP via the UV curing polymerization method. The prepared PETA-microencapsulated APP（PETA-APP） was characterized by Fourier transform infrared spectroscopy（FTIR）, scanning electron microscopy（SEM）, and thermogravimetric（TG） analysis. PETA-APP was used as intumescent flame retardant（IFR） alone to flame retard polypropylene（PP）. The water resistance of PP/PETA-APP composites was investigated, and the effect of PETA on the combustion behaviors of PP/APP composites was studied through limiting oxygen index（LOI）, vertical burning test（UL-94） and cone calorimeter（CC） test, respectively. With 40 wt% of PETA-APP, the PP/PETA-APP system could achieve a LOI value of 30.0% and UL-94 V-0 rating after treatment in hot water for 168 h, while the LOI value of the system containing 40 wt% uncoated APP was only 19.2%, and it failed to pass the UL-94 rating. CC test results showed that the heat release rate（HRR）, mass loss rate（MLR） and smoke production rate（SPR） of PP/PETAAPP system decreased significantly compared with PP/APP system, especially the peak of HRR was decreased by 51.4%. The mechanism for the improvement of flame reatardancy for PP/PETA-APP composites was discussed based on FTIR and X-ray photoelectron spectroscopy（XPS） tests. All these results illustrated that simultaneous improvement of flame retardancy and water resistance for PP/APP was achieved through coating UV-curable PETA onto APP.
基金
financially supported by the National Natural Science Foundation of China(Nos.50933005,51121001)
the Program for Changjiang Scholars and Innovative Research Team in Universities(IRT1026)
