Nonisothermal crystallization behavior of melt‐intercalated polyethylene‐clay nanocomposites

Abstract

The influence of nanoclay particles on the nonisothermal crystallization behavior of intercalated polyethylene (PE) prepared by melt-compounding was investigated. It is observed that the crystallization peak temperature (T p ) of PE/clay nanocomposites is slightly but consistently higher than the neat PE at various cooling rates. The half-time (t 0.5 ) for crystallization decreased with increase in clay content, implying the nucleating role of nanoclay particles. The nonisothermal crystallization data are analyzed using the approach of Avrami (Polymer 1971, 12, 150), Ozawa (Polym Eng Sci 1997, 37, 443), and Mo and coworkers (J Res Natl Bur Stand 1956, 57, 217), and the validity of the different kinetic models to the nonisothermal crystallization process of PE/clay nanocomposites is discussed. The approach developed by Mo and coworkers successfully explains the nonisothermal crystallization behavior of PE and PE/clay nanocomposites. The activation energy for nonisothermal crystallization of neat PE and PE/clay nanocomposites is determined using the Kissinger (J Res Natl Bur Stand 1956, 57, 217) method.

Effect of functionalized SWCNTs on microstructure of PP‐g‐MA/OMMT/f‐SWCNTs nanocomposite

“…This maybe ascribed to the lower mobility of polymer chains in matrix due to the addition of nanofillers. The similar results have been reported by Yuan et al14 In their opinion, the dispersed nanoparticles hindered the formation of large crystalline domains in the restricted and confined space.…”

“…The interfacial interaction between polymer matrix and OMMT is proved to be fundamental to the final state of OMMT in polymer matrix,10, 11 and also to the crystallization behavior of polymer in the nanocomposites 12, 13. A significant work about the interaction of polyolefin nanocomposites based on clay has been done by Misra and coworkers recently 14, 15. They found that the interaction in PE/clay nanocomposites was very weak compared with the interaction in PP/clay nanocomposites, which results in different crystallization behaviors and structures in PE/clay compared with those in PP/clay nanocomposites.…”

Influence of nanofiller dimensionality on the crystallization behavior of HDPE/carbon nanocomposites

“…The crystallization behavior of polymer matrix, which is of significant importance for real industrial processing, could also be influenced by the dispersed nanofillers and hence has aroused wide attention of researchers. It was found that the layered silicates,2–7 spherical silica,8 and calcium carbonate9 played two different roles during polymer crystallization: as heterogeneous nucleating agent which promoted polymer crystallization and as a hindrance which retarded polymer crystallization growth. Generally, these effects are dependent on the content, the geometry, and the dispersion state of the nanofillers in the polymer as well as the crystallization temperature.…”

The Crystallinity Behavior of Polyethylene/Clay Nanocomposites Under the Influence of Water-Assisted Melt Blending

“…This contradictive behavior was observed in PEO= montmorillonite [23] , PP=clay [31] and PA-6=clay nanocomposites [32] , exhibiting improved crystallinity and almost retarded growth, respectively at low and high clay contents. It is worth to mention that confinement of polymer chains in PP-and PA-based nanocomposites normally leads to c nucleation; whereas, a specified trend is not observed for PE nanocomposites due to weak polymer-clay interactions [18,29] .…”