Structure–property relationship in PP/LDPE blend composites: The role of nanoclay localization

Abstract

This article reports, for the first time, on how the kinetics and thermodynamics of the melt‐processing control the nano/micro‐structure development and properties of nanoclay‐filled polypropylene (PP)/low‐density polyethylene (LDPE) blend ternary composites. Morphological characterization suggests that the nano/micro‐structure of the PP/LDPE (80/20) blend can be controlled by incorporating nanoclay alone or by adding a mixture of organoclay and maleated compatibilizers. Simultaneous mixing of PP, LDPE, maleated compatibilizers, and organoclay results in homogeneous distribution of intercalated silicate layers in all the phases of the blend, a feature which profoundly affects the thermal stability and tensile and rheological properties of the blend composites. For example, the elongation‐at‐break for PP increases from 28.1 to 155.6% for composite containing both organoclay and maleated compatibilizers, whereas the thermal stability for PP increases from 269.8 to 303.3 °C for the same composite. However, the impact strength of the PP/LDPE blend decreases with incorporation of organoclay, regardless of the phase in which the nanoclay particles are localized. In summary, the obtained results show that regardless of the phase in which the nanoclay is localized, the morphology, and hence the properties, of the ternary composites are superior to those of the neat blend. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46193.

Miscible/partially‐miscible blends of polypropylene—the mechanisms responsible for the decrease of yield stress

“…In many miscible or partially‐miscible blends of semicrystalline polymer/non‐cocrystallizing low molecular weight component the reduction of yield stress in comparison to reference material is observed. The effect of reduction of the value of yield stress is clearly seen at relatively low contents of non‐cocrystallizing component (from few to over a dozen of wt %) and may amount to 50%–75%, when the content of the component is increased up to 30 wt % . At the same time, full understanding of the influence of the presence of non‐cocrystallizing component on nano/microstructure of a polymer matrix and changes of yield stress has not been achieved.…”

Effect of organically modified layered double hydroxides on the properties of poly(lactic acid)/poly[(butylene succinate)‐co‐adipate] immiscible blends

“…obtained favored localization of organically modified cationic clays in PBSA phase in a PLA/PBSA blend with clay loading up to 1.0 wt% above which the clay particles were distributed in both polymer matrices. Mofokeng et al . also observed the interfacial dispersion of the clay particles in polypropylene/low‐density polyethylene (PP/LDPE) blend with 4.0 wt% clay loading.…”

Influence of Selectively Localised Nanoclay Particles on Non-Isothermal Crystallisation and Degradation Behaviour of PP/LDPE Blend Composites

“…The 80/20/0/0/4 nanocomposite has a higher %χpp than the neat blend and other ternary nanocomposites, suggesting increased crystallisability. This is attributed to the observed localisation of clay tactoids at the PP/LDPE interface in Figure 2a promoted by the poor interaction of the clay with either PP or LDPE [18]. Therefore, the clay tactoids at the interface for the 80/20/0/0/4 nanocomposite, which do not interact well with the blended polymers, make it easy for the PP matrix to undergo the chain-folding process.…”

“…The crystallisabilty of PP in the blend composites is influenced by intervention of nanoclay and dispersion of the LDPE phase. Briefly, the TEM images in Figure 2 of the PP- g -MA and PE- g -MA-containing blend composites show well-distributed and dispersed clay particles in the polymeric phases, and more details can be found in our previous study [ 18 ]. In addition, the LDPE phase is better dispersed in the PP- g -MA and PE- g -MA-containing blend composites due to combined interventions of clay and maleated compatibilisers.…”

“…The selective localisation of nanofillers in different polymeric phases of blend composites may influence the crystallisation and thermal degradation kinetics differently, and inadequate work has been carried out on this topic. Given this background, we have previously melt-mixed clay containing PP/LDPE blend composites in the absence and presence of compatibilisers, PP- g -MA and maleated polyethylene (PE- g -MA), and investigated how the localisation of organically modified nanoclay particles affects the morphological development—and hence the properties—of the obtained composites [ 18 ]. Nanoclay was used as nanofiller to produce the blend composites due to its significant property enhancement at low loading, commercial availability, cost effectiveness, and relatively simple processability [ 19 ].…”