Thermal degradation and crystallization behavior of blend‐based nanocomposites: Role of clay network formation

Abstract

ABSTRACT:The main goal of this study is to explicate the exact role of nanoclay particles on thermal degradation mechanism and crystallization behavior of blend-based nanocomposites. Thermoplastic olefin (TPO) nanocomposites, as a simple model, were prepared via melt mixing in an internal batch mixer. X-ray diffractometry (XRD) and transmission electron microscopy tests show that a relatively good dispersion of silicate layers was obtained in the system. On the addition of nanoclay, a remarkable reduction in rubber domain size was observed through scanning electron microscopy (SEM). Thermogravimetric analysis shows that nanoclay particles can retard thermal decomposition process. Thermal degradation kinetic studies, using Flynn-Wall-Ozawa method, reveal that addition of nanoclay contents higher than 1 wt % changes the mechanism of thermal degradation. A mechanism was proposed to explain this phenomenon based on SEM images of char residues. Non-isothermal crystallization behavior of samples was investigated using differential scanning calorimeter. The unexpected reduction in crystallinity of TPO nanocomposites containing 5 wt % nanoclay was explained using rheometry analysis and attributed to the formation of stable percolated clay networks in this sample.

Microstructure–property relationships of organo-montmorillonite/polyurethane nanocomposites: Influence of hard segment content

“…Additionally, the melting curves were narrower (smaller full width at half maximum) in all nanocomposite samples relative to their equivalent PU system. This phenomenon, which indicates an increased crystallization rate in the nanocomposites has been addressed in other reports (Seyfi et al, 2012;Pérez et al, 2014;Xu et al, 2014) and further verified that the presence of clay layers facilitated heterogeneous nucleation. No soft segment glass transition was observed in the DSC thermograms.…”

Effect of lignin removal on mechanical, thermal, and morphological properties of polylactide/starch/rice husk blend used in food packaging

“…Conversely, lignin can act as obstacle for mobility of the PLLA chains to fold and join the crystallization growth front, finally leading to a reduction in the extent of crystallinity. This reduction in degree of crystallization could results in lower amount of T g due to effect on amorphous phase . In conclusion, these two effects are the main dominating factors affecting the transition process and as could be seen these two effects counteract each other leading to no significant change in T g .…”

“…To investigate the effect of various loadings of RH and bleaching on the thermal behavior of starch–PLLA, DSC measurements were carried out. As most of the processing methods occur under nonisothermal conditions, the understanding of polymer crystallization under dynamic condition is of considerable importance . The crystallization exotherms of blends are presented in Figure .…”

Investigating the Effect of Treated Rice Straw in PLLA/Starch Composite: Mechanical, Thermal, Rheological, and Morphological Study

“…The presence of voids obstructs stress propagation when tensile stress is applied inducing some increased brittleness. [41][42][43] Elastic modulus shows a descending trend upon addition of fillers, which is due to the plasticizer role of lignin. Owing to the hot water treatment, the free silica particles have been removed, and the effect of lignin may be explored.…”