Flammability and thermal behaviors of polypropylene composite containing modified kaolinite

Exfoliatied kaolinite (E-Kaol) was prepared by intercalating DMSO and KAc into kaolinite successively followed by irradiation under ultrasonic. The modified kaolinite was then introduced to polypropylene (PP) by melt blending in order to improve the fire performance of the composite. The flammability and thermal behaviors of PP composite were analyzed by limit oxygen index, vertical burning test, cone calorimeter test, and thermal-gravimetric analysis, respectively. The microstructure of PP composites was characterized by Fourier-transformed infrared spectroscopy, X-ray diffraction, and scanning electron microscope (SEM). It was demonstrated the presence of only 1 phr E-Kaol could improve the LOI values of PP/MCAPP/ATH composite from 26.4 to 28.0, and decrease the peak value of heat release rate and smoke production rate of the PP/MCAPP/ATH by 60.7% and 39.1%, respectively, compared with that of PP sample. Morphology analysis by SEM showed that E-Kaol in PP composite was beneficial to forming rigid and compact char structure. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41761.