Effects of halloysite nanotubes on the mechanical, thermal, and flammability properties of PP‐g‐MAH compatibilized polyethylene terephthalate/polypropylene nanocomposites

Abstract

This work investigates the effect of HNTs content on the mechanical, thermal and flammability properties of polypropylene grafted maleic anhydride (PP‐g‐MAH) compatibilized polyethylene terephthalate/polypropylene (PET/PP) blends. The synthesized composites were characterized after compounding using a twin‐screw extruder and injection‐molding machine. The tensile, flexural and impact strengths values peaked at 2 parts per hundred resin (phr). Thermogravimetric analysis showed a marked improvement in thermal stability of the fabricated composites. A gradual increase in T50 and Tmax with increasing HNTs content was observed. The limiting oxygen index revealed a linear relationship with HNTs content. Transmission electron microscopy images showed uniform dispersion of nanotubes at lower HNTs content and agglomerated structures were formed at higher HNTs content due to inter‐tubular interactions both in face‐to‐face or face‐to‐edge manner. The improvements in thermal stability and flammability are attributed to these interactions. Due to improved mechanical properties and flammability, the fabricated composites have potential applications in automotive industries. POLYM. COMPOS., 39:E1554–E1564, 2018. © 2017 Society of Plastics Engineers

An approach to the optimization of mechanical properties of polypropylene/nitrile butadiene rubber/halloysite nanotube/polypropylene‐g‐maleic anhydride nanocomposites using response surface methodology

“…The finer dispersion and better interfacial adhesion of HNTs with PP in the presence of PP‐ g ‐MA and also their high aspect ratio and high mechanical properties are the reason for the ascending trend of HNTs' effect on tensile strength because of load transfer from matrix to HNTs. The enhancing effect of HNTs on the tensile strength of PP‐based nanocomposites was also reported in other papers . Kubade and Tambe reported the superior dispersion of HNTs in PP/ABS nanocomposite as a result of using PP‐ g ‐MA.…”

“…This result is consistent with the study by Prashantha et al in which HNTs enhanced the impact strength of PA6/HNT nanocomposites until 4 wt% of loading. Inuwa et al also reported that, after 2 phr of HNT loading, stress concentration points reduced the impact strength of PET/PP/HNT nanocomposite. There are also other papers reporting the optimum level of HNT loadings for the impact strength of nanocomposites .…”

“…They concluded that the refinement in dispersed ABS phase morphology and enhanced dispersion of HNTs resulting from the PP‐ g ‐MA compatibilizer cause a significant enhancement in tensile properties. Moreover, Inuwa et al showed that the hydrogen bonding between HNTs and PP‐ g ‐MA was the only form of interaction occurring between the MA of PP‐ g ‐MA and HNTs. They reported that the better dispersion of HNTs is due to the MA of PP‐ g ‐MA which can act as an emulsifier whereby more PET and PP can penetrate HNTs galleries.…”

“…They also cost much less in comparison with other nanotubes such as MWCNTs, and this is one of the reasons why much attention has recently been paid to these nanotubes to see whether they can be an alternative to expensive common nanotubes . PP‐ g ‐MA has been used as a compatibilizer to improve polymer/HNTs interactions in some studies …”

Polypropylene/phosphazene nanotube nanocomposites: Thermal, mechanical, and flame retardation studies

“…[8,9] Small fractions of one-dimensional (1-D) fibrous fillers have been reported to significantly enhance the mechanical properties of the polymer matrices, owing to the large aspect ratios and polymer-fiber interactions. [10,11] Interestingly, recent reports have revealed that the addition of the fibrous materials, such as halloysite, [12] carbon nanotubes (CNTs), [13,14] and natural fibers, [15,16] significantly improved the impact strength of PP due to the formation of a network structure within the polymer matrix. However, the uniform dispersion of 1-D materials in the polymer matrices is a significant challenge, and the fiber agglomerates in the matrix can lead to a reduction in the ductility and toughness of the material, thus leading to poor thermal stability and mechanical performance.…”