Nanocomposites Prepared with High Density Polyethylene and Carbon Nanofibers Modified by Ethylene Plasma

Abstract

Carbon nanofibers (CNFs) are surface-modified by plasma polymerization using ethylene as monomer. The modified CNFs are suitable to be mixed with different polyethylenes. In this study, we mix them with high density polyethylene (HDPE). The plasma-coated CNFs (pCNFs) are then characterized by Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA), and Scanning Electron Microscopy (SEM) in the transmission mode (STEM). Treated and untreated CNFs are evaluated in water, chloroform, and 1,2,3-trichlorobenzene (TCB) to evaluate their effective dispersion in these three solvents. FTIR spectra showed signals corresponding to the organic part deposited on the surface of pCNFs. The TGA analysis makes it possible to confirm that pCNFs have a higher weight loss than CNFs because of the volatilization of the plasma polymerized ethylene coating. Dispersion tests showed that pCNFs dispersed well in TCB and chloroform solvents. To prepare nanocomposites, HDPE and CNFs are mixed well in a single-screw extruder with an attached sonication chamber at its exit. Nanocomposites containing 1% and 3% by weight of CNFs are prepared. The products are analyzed by the Young's modulus and evaluated for thermal stability.

Surface Modification of Sodium Montmorillonite Nanoclay by Plasma Polymerization and Its Effect on the Properties of Polystyrene Nanocomposites

“…This study is expected to see an increase in interaction between the nanoclay modified with plasma and the matrix, when of both phases are the same. In previous studies, this polymeric coating has already been confirmed on other different nanomaterials using plasma polymerization [5,15,39].…”

“…In samples of PS/Na + -MMT/MMA and PS/Na + -MMT/St nanocomposites, the results indicate that there is no evidence of a significant level of exfoliation or intercalation of Na + -MMT modified by plasma in the PS/Na + -MMT nanocomposites, possibly because the coating formed by plasma on the nanoclay does not allow the introduction of the St or MMA polymer in-between the nanoclay galleries. This, however, does not contradict the surface interaction results demonstrated by the article which are attributed to the compatibility of the coating of the nanoclay Na + -MMT/St with the PS matrix, as well as the shear stress during melt mixing [39].…”

“…In general, it was observed that the dispersion of Na + -MMT/MMA or Na + -MMT/St was poor with solvents of high polarity like water = 23.5, while their dispersion was better in a medium of low polarity such as THF ( = 9.52) or chloroform ( = 9.21), as of PMMA and PS are 9.25 and 9.12, respectively. are very similar to the last two solvents causing a good dispersion between them [5,15,39].…”

“…Reported works using plasma modification of nanoclays and other nanoparticles to prepare polymer composites have presented favorable improvements in particle dispersion as well as thermal, mechanical, and gas barrier properties [5,15,16,[39][40][41]. According to Ramos-de Valle et al, these dispersion improvements have allowed the investigation of the effects of styrene plasma modified CNFs to investigate the effects on the tensile properties of polystyrene/CNF composites [5].…”

Mechanical and thermal properties of polyethylene/carbon nanofiber composites produced by rotational molding

“…To this end, surfactants, mechanical mixing, or surface modifications have been proposed . For CNF surface functionalization, several methods like acid oxidative solution, compatibilizer addition, thermal oxidation, plasma coating, and plasma oxidation have been proposed.…”