Characterization of PP/HDPE blend-based nanocomposites using different maleated polyolefins as compatibilizers

Nanocomposites based on a polypropylene (PP)/high density polyethylene (HDPE) blend were prepared using an organo-montmorillonite (15A) as a nano-filler and two maleated polyolefins (PE-MA and PP-MA) as compatibilizers. The phase morphology and typical physical properties of the prepared samples were examined. The nano-filler 15A was intercalated and/or partially exfoliated in the blend when PE-MA or PP-MA was present. The PE-MA facilitated the dispersibility of 15A to a better degree. The nano-filler 15A accelerated the crystallization of PP in the blends, whereas it hardly influenced the crystallization of HDPE. Moreover, at a slow cooling rate (i.e., 1 °C/min) the PP-MA induced a higher crystallization temperature for PP in the composite, while PE-MA impeded PP crystallization. On the other hand, the crystallization of HDPE in the composite was only slightly influenced by the presence of PE-MA or PP-MA. The thermal stability of PP/HDPE blend was enhanced after the addition of 15A regardless of the inclusion or not of PE-MA or PP-MA. The enhancement was more evident when the samples were scanned under an air environment than a N2 environment. The stiffness of PP/HDPE blend increased marginally after adding 15A and was slightly altered with the further inclusion of PP-MA. The presence of PE-MA in the composite caused a slight decline in the stiffness. The impact strength of PP/HDPE blend declined after the formation of nanocomposites, especially for the sample incorporating PP-MA.