Nanocompósitos de polietileno/argila bentonítica com propriedades antichama.

Abstract

HOPE nanocomposites were prepared by melt intercalation, in order to examine the fiame retardant effect of this material For the development of nanocomposites were used the clay montmoriilonite (MMT), organoclay (OMMT) and flame retardant (RCP) with the percentage of 1, 3, 6 and 9 wt%. Grafted polyethylene with maleic anhydride (PE-g-MA) was used as a compattbilizer of the systems. HOPE and its systems were evaluated: XRD, TEM, SEM, mechanical properties (tensile and impact), HDT, DSC, TG and fiammability (UL94HB, oxygen index (LOI) and cone calorimetry). The X-ray diffraction showed an apparent partial intercalation and exfoliation as well as formation of rnicrocomposite. The phase morphology of the systems obtained from the SEM showed dispersion and distribution of clay and flame retardancy. By TEM it was observed that the system with 1% OMMT clay showed a predominance of exfoliation. Already the system with 3% OMMT showed partial exfoliation and exfoliation is reducing as the clay content increased. Comparing the mechanical properties of the HDPE to systems it was found that the elastic modulus practically was not changed. By TG it was seen that MMT, OMMT and RCP acted improving the thermal behavior of the nanocomposites compared to HDPE matrix. By DSC it was observed that the presence of clay altered the crystallinity of the matrix. The results obtained for the oxygen index revealed that both HDPE and their systems presented flame retardant properties. By means of the horizontal fiammability tests, it was found that the presence of 1 % MMT clay reduced 25% the fiammability of HDPE. By cone calorimetry was found that the system contains 9% of OMMT clay decreased by 33% the fiammability of nanocomposites.