Abstract Under injection molding conditions, typical of industrial processing, in situ polymerized montmorillonite/polyamide 6 nanocomposites significantly degraded, producing a four-fold increase in e-caprolactam (monomer) content and a significant reduction in number average molecular mass, as compared to the as-received nanocomposite. Degradation was believed to occur via peptide bond scission following attack by water that is most likely released from the polymer and the montmorillonite clay surface at the 300 °C (12.5 min) processing conditions. Under identical injection molding conditions, virgin polyamide 6 number average molecular mass did not decrease (within experimental uncertainty); however, a small increase in monomer content was observed. Characterization methods included solution 13 C nuclear magnetic resonance spectroscopy, infrared spectroscopy, gel-permeation chromatography, and thermal gravimetric analysis.

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Processing Degradation of Polyamide 6/Montmorillonite Clay Nanocomposites and Clay Organic Modifier | NIST

Fabrication of polymer nanocomposites via ball milling: Present status and future perspectives

Effect of functional groups in acid constituent of deep eutectic solvent for extraction of reactive lignin

Pineapple peel is a renewable agricultural residue available in abundance whose multipurpose utilization deserves more attention. The present study aimed at the isolation of nanocellulose from pineapple peel and evaluation on its reinforcement capability for gellan gum film. The results from scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) indicated the progressive removal of non-cellulosic components and the non-destruction of cellulose structure following bleaching and alkali treatments. Atomic force microscopy image of the nanocellulose displayed a needle-like structure with averages of 15 ± 5 nm in diameter and 189 ± 23 nm in length.
 Thermal gravimetric analysis (TGA) indicated that the obtained fibres after bleaching and alkali treatments showed higher thermal stability than the untreated pineapple peel. Although showing an earlier initial degradation temperature, the obtained nanocellulose remained the maximum residue after being heated to 500 °C. The rheological results indicated that the viscosities of the nanocellulose/gellan gum solutions increased slightly with the increase of nanocellulose content. The prepared films were characterized by FTIR, SEM, XRD, TGA, light transmittance and mechanical properties. The introduction of nanocellulose decreased light transmittance values but enhanced the thermal stability of gellan gum film. Compared with the neat gellan gum film, the 4% nanocellulose loaded gellan gum film showed 48.21% improvement in tensile strength.

Utilization of pineapple peel for production of nanocellulose and film application

A review of nanocellulose as a new material towards environmental sustainability.

Nanocrystalline cellulose extracted from pine wood and corncob

Effect of reprocessing and clay concentration on the degradation of polypropylene/montmorillonite nanocomposites during twin screw extrusion

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Effect of Compatibilization and Reprocessing on the Isothermal Crystallization Kinetics of Polypropylene/Wood Flour Composites

Remarkable change in the broadband electrical behavior of poly(vinylidene fluoride)–multiwalled carbon nanotube nanocomposites with the use of different processing routes

Ultra-high molecular weight polyethylene (UHMWPE) is a polyethylene with a very long chain, which provides excellent features, however it makes the processing difficult due to high melt viscosity. Many studies intend to found out means to make its processing easier. Recently, the high-energy mechanical milling has been used for polymeric materials and it was detected that physical and chemical changes occur during milling. In such case, powder of UHMWPE was milled in three types of mills: SPEX, attritor e planetary, in different times of milling. The polymer was characterized by SEM and XRD. Thus, it was observed that the material processed in attritor mill showed larger phase transformation from orthorhombic to monoclinic. This is most likely due to the smaller milling temperature of attritor mill when compared with the other two mills and the high shear force generated during milling.

Benjamim de Melo Carvalho

Papers

Nanocrystalline cellulose extracted from pine wood and corncob

Effect of reprocessing and clay concentration on the degradation of polypropylene/montmorillonite nanocomposites during twin screw extrusion

Effect of Compatibilization and Reprocessing on the Isothermal Crystallization Kinetics of Polypropylene/Wood Flour Composites

Remarkable change in the broadband electrical behavior of poly(vinylidene fluoride)–multiwalled carbon nanotube nanocomposites with the use of different processing routes

High-Energy Mechanical Milling of Ultra-High Molecular Weight Polyethylene (UHMWPE)