Crystallization kinetics of high‐density and low‐density polyethylene on carbon nanotubes

Abstract

This study presents a comparative analysis of the crystallization behavior of low‐density polyethylene (LDPE) and high‐density polyethylene (HDPE) nanocomposites. Carbon nanotubes (CNTs) were used as a nucleating agent to generate a nanohybrid shish‐kebab architecture. Materials characterizations were performed to evaluate the crystal morphology and crystallization kinetics using scanning electron microscopy (SEM) and differential scanning calorimetry (DSC), respectively. The lamellae of polyethylene were always found to grow laterally on the tube axis of CNTs. The parameters of the Avrami model for primary crystallization were determined. SEM indicated the crystal morphology changed from spherulitic to disk‐shaped with the addition of CNTs, while DSC‐based thermal examination indicated that the CNTs can provide nucleation sites to polyethylene to accelerate the crystal growth rate. HDPE was found to crystallize faster than LDPE on CNTs. The highly branched nature of LDPE's macromolecular chains are known to cause reduced chain mobility, which resulted in lower crystallinity values with smaller crystallite sizes for LDPE in this study. In comparison, the more linear HDPE chains have an increased polymer density and chain mobility, resulting in an improved nucleation ability of HDPE chain segments on CNTs.

Influence of graphene nanoscrolls on the crystallization behavior and nano‐mechanical properties of polylactic acid

“…Fundamentally, crystallization involves two stages: nucleation and crystal growth. In our continuous efforts to realize the potential of CNTs to induce polymer crystallization, we found that carbon‐based nanoparticles are effective agents that facilitate nucleation; however, the second stage of growth is governed by space …”

“…In our continuous efforts to realize the potential of CNTs to induce polymer crystallization, we found that carbon-based nanoparticles are effective agents that facilitate nucleation; however, the second stage of growth is governed by space. [31][32][33][34] It has been previously reported that the dimensionality of carbon nanoparticles primarily governs the supramolecular architecture of the crystallized polymer. 24,35 As seen in SEM images of PLA-GNS, the polymer seems to be crystallized randomly on the surface of GNS in multiple orientations to generate a flower-like, petal-shaped structure.…”

The mobility of PEG chains versus micellar stability towards the formation of PE‐b‐PEG nanohybrid shish‐kebab on carbon nanotubes

“…These results are consistent with the transcrystalline layer deposited in between the adjacent kebabs and on the long axis of CNTs (SEM and TEM results). This transcrystalline layer results into a less compact lamella, hence decrease the crystallite size …”

“…The crystallinity or crystallinity index (CI) was determine as per reported protocol. [50][51][52] The CI of the pure polymer was 49%. The value of CI was lowest for 50-50-LMW (21%), slightly higher for 50-50-HMW (51%), intermediary for 20PE-80PEG (54%), and highest for 80PE-20PEG (64%).…”

Pure and complex nanostructures using poly[bis(triiso‐propylsilylethynyl) benzodithiophene‐bis(decyltetradecyl‐thien) naphthobisthiadiazole], carbon nanotubes and reduced graphene oxide for high‐performance polymer solar cells

“…On the basis of DSC analyses, Dias and Yerushalmi‐Rozen reported a significant increase in polymer crystallinity in CNT composites. The crystallization kinetics of high‐density and low‐density polyethylenes on CNTs were also investigated by Depan et al . The induced crystallization of P3ATs onto graphenic materials was also widely reported; e.g.…”