scholarly journals Graphene and Polyethylene: A Strong Combination Towards Multifunctional Nanocomposites

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2094 ◽  
Author(s):  
Mar López-González ◽  
Araceli Flores ◽  
Fabrizio Marra ◽  
Gary Ellis ◽  
Marián Gómez-Fatou ◽  
...  
Keyword(s):  
Load Transfer ◽  
Barrier Properties ◽  
Thermal And Mechanical Properties ◽  
Gas Barrier ◽  
Chemically Modified ◽  
The Matrix ◽  
Experimental Approaches ◽  
Efficient Load Transfer ◽  
Modified Graphene ◽  
Multifunctional Nanocomposites

The key to the preparation of polymer nanocomposites with new or improved properties resides in the homogeneous dispersion of the filler and in the efficient load transfer between components through strong filler/polymer interfacial interactions. This paper reports on the preparation of a series of nanocomposites of graphene and a polyolefin using different experimental approaches, with the final goal of obtaining multifunctional materials. A high-density polyethylene (HDPE) is employed as the matrix, while unmodified and chemically modified graphene fillers are used. By selecting the correct combination as well as the adequate preparation process, the nanocomposites display optimized thermal and mechanical properties, while also conferring good gas barrier properties and significant levels of electrical conductivity.

scholarly journals Fire and Gas Barrier Properties of Poly(styrene-co-acrylonitrile) Nanocomposites Using Polycaprolactone/Clay Nanohybrid Based-Masterbatch

2008 ◽  
Vol 2008 ◽  
pp. 1-11 ◽  
Author(s):  
S. Benali ◽  
A. Olivier ◽  
P. Brocorens ◽  
L. Bonnaud ◽  
M. Alexandre ◽  
...  
Keyword(s):  
Barrier Properties ◽  
Hydroxyl Groups ◽  
Gas Barrier ◽  
Clay Dispersion ◽  
Force Microscopy ◽  
Atomic Force ◽  
The Matrix ◽  
Inorganic Content ◽  
Barrier Resistance ◽  
Silicate Layers

Exfoliated nanocomposites are prepared by dispersion of poly(ε-caprolactone) (PCL) grafted montmorillonite nanohybrids used as masterbatches in poly(styrene-co-acrylonitrile) (SAN). The PCL-grafted clay nanohybrids with high inorganic content are synthesized by in situ intercalative ring-opening polymerization ofε-caprolactone between silicate layers organomodified by alkylammonium cations bearing two hydroxyl functions. The polymerization is initiated by tin alcoholate species derived from the exchange reaction of tin(II) bis(2-ethylhexanoate) with the hydroxyl groups borne by the ammonium cations that organomodified the clay. These highly filled PCL nanocomposites (25 wt% in inorganics) are dispersed as masterbatches in commercial poly(styrene-co-acrylonitrile) by melt blending. SAN-based nanocomposites containing 3 wt% of inorganics are accordingly prepared. The direct blend of SAN/organomodified clay is also prepared for sake of comparison. The clay dispersion is characterized by wide-angle X-ray diffraction (WAXD), atomic force microscopy (AFM), and solid state NMR spectroscopy measurements. The thermal properties are studied by thermogravimetric analysis. The flame retardancy and gas barrier resistance properties of nanocomposites are discussed both as a function of the clay dispersion and of the matrix/clay interaction.

Preparation and Characterization of High Performance LLDPE/Graphene Nanocomposites

2011 ◽  
Vol 410 ◽  
pp. 152-155 ◽  
Author(s):  
Tapas Kuila ◽  
Bong Joo Jung ◽  
Xiao Fei Yi ◽  
Joong Hee Lee
Keyword(s):  
High Performance ◽  
Barrier Properties ◽  
Functionalized Graphene ◽  
Transmission Electron Microscopy Analysis ◽  
Gas Barrier ◽  
Graphene Nanocomposites ◽  
Transmission Electron ◽  
Electron Microscopy Analysis ◽  
Mixing Method ◽  
Modified Graphene

The nanocomposites containing linear low density polyethylene (LLDPE) and dodecyl amine (DA) modified graphene (DA-G) as nanofiller have been prepared by solution-mixing method and characterized. Transmission electron microscopy analysis of the nanocomposites exhibits homogeneous dispersion of graphene in the LLDPE matrix. Thermal stability of the nanocomposites with 1 wt.% DA-G are superior as compared to neat LLDPE. Gas barrier properties of the nanocomposites are also much better than that of the neat LLPDE. Co-efficient of thermal expansion values of the nanocomposites decreases with the addition of functionalized graphene. Keywords: Functionalized graphene; UV-Vis spectra; Nanocomposites; Gas barrier property; Mechanical property

scholarly journals Mechanically Reinforced, Flexible, Hydrophobic and UV Impermeable Starch-Cellulose Nanofibers (CNF)-Lignin Composites with Good Barrier and Thermal Properties

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4346
Author(s):  
Yadong Zhao ◽  
Christofer Troedsson ◽  
Jean-Marie Bouquet ◽  
Eric M. Thompson ◽  
Bin Zheng ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Food Packaging ◽  
Cellulose Nanofibers ◽  
Composite Films ◽  
Barrier Properties ◽  
Gas Barrier ◽  
Good Thermal Stability ◽  
Flexible Films ◽  
Functional Additive ◽  
The Matrix

Bio-based composite films have been widely studied as potential substitutes for conventional plastics in food packaging. The aim of this study was to develop multifunctional composite films by introducing cellulose nanofibers (CNF) and lignin into starch-based films. Instead of costly and complicated chemical modification or covalent coupling, this study optimized the performance of the composite films by simply tuning the formulation. We found that starch films were mechanically reinforced by CNF, with lignin dispersing as nanoparticles embedded in the matrix. The newly built-up hydrogen bonding between these three components improves the integration of the films, while the introduction of CNF and lignin improved the thermal stability of the starch-based films. Lignin, as a functional additive, improved hydrophobicity and blocked UV transmission. The inherent barrier property of CNF and the dense starch matrix provided the composite films with good gas barrier properties. The prepared flexible films were optically transparent, and exhibited UV blocking ability, good oxygen-barrier properties, high hydrophobicity, appreciable mechanical strength and good thermal stability. These characteristics indicate potential utilization as a green alternative to synthetic plastics especially for food packaging applications.

scholarly journals Influence of Thickness and Lateral Size of Graphene Nanoplatelets on Water Uptake in Epoxy/Graphene Nanocomposites

2018 ◽  
Vol 8 (9) ◽  
pp. 1550 ◽  
Author(s):  
Silvia Prolongo ◽  
Alberto Jiménez-Suárez ◽  
Rocío Moriche ◽  
Alejandro Ureña
Keyword(s):  
Mechanical Properties ◽  
Glass Transition ◽  
Barrier Properties ◽  
Graphene Nanoplatelets ◽  
Lateral Size ◽  
Thermal And Mechanical Properties ◽  
Graphene Nanocomposites ◽  
Aspect Ratios ◽  
Dispersion Degree ◽  
The Matrix

In this study, the hydrothermal resistance of an epoxy resin (aircraft quality) reinforced with graphene is analyzed. Different geometries and aspect ratios (thickness and lateral dimensions) of graphene nanoplatelets were studied. The addition of these graphene nanoplatelets induces important advantages, such as an increase of the glass transition temperature and stiffness and an enhancement of barrier properties of the epoxy matrix, in spite of the excellent behavior of pristine resin. The effectiveness of graphene nanoplatelets increases with their specific surface area while their dispersion degree is suitable. Thinner nanoplatelets tend to wrinkle, decreasing their efficiency as nanofillers. Graphene used as reinforcement not only reduces the absorbed moisture content but also decreases its effect on the thermal and mechanical properties related to the matrix.

In situ solution polymerization for preparation of MDI-modified graphene/hyperbranched poly(ether imide) nanocomposites and their properties

RSC Advances ◽  
2016 ◽  
Vol 6 (1) ◽  
pp. 716-729 ◽  
Author(s):  
Quantao Li ◽  
Wenqiu Chen ◽  
Wei Yan ◽  
Quanyuan Zhang ◽  
Changfeng Yi ◽  
...  
Keyword(s):  
Barrier Properties ◽  
Solution Polymerization ◽  
Gas Barrier ◽  
Hyperbranched Poly ◽  
Thermal Imidization ◽  
Modified Graphene ◽  
Gas Barrier Properties

Two kinds of (GE-MDI/HBPEI) nanocomposites with highly enhanced thermal, mechanical and gas barrier properties, were prepared via in situ solution polymerization, as well as subsequent synchronous thermal imidization and reduction.

scholarly journals Structure-Gas Barrier Property Relationship in a Novel Polyimide Containing Naphthalene and Amide Groups: Evaluation by Experiments and Simulations

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1402
Author(s):  
Yi Zeng ◽  
Yiwu Liu ◽  
Jinghua Tan ◽  
Jie Huang ◽  
Junjie Liu ◽  
...  
Keyword(s):  
Electronic Device ◽  
Transmission Rate ◽  
Barrier Properties ◽  
Naphthalene Ring ◽  
Gas Barrier ◽  
Positron Annihilation Lifetime ◽  
Oxygen Transmission Rate ◽  
Hydrogen Bond Interactions ◽  
The Matrix ◽  
Dynamics Simulations

In order to meet the increasingly stringent requirements for heat resistance and barrier properties in the packaging and electronic device encapsulation field. A high-barrier polyimide (NAPPI) contains naphthalene ring and amide group was prepared by polymerization of a novel diamine (NAPDA) and pyromellitic dianhydride. The structure and properties of diamine monomers and polymers were characterized. Results show that the NAPPI exhibits superior barrier properties with extremely low water vapor and oxygen transmission rate values of 0.14 g·m−2·day−1 and 0.04 cm3·m−2·day−1, respectively. In addition, the NAPPI presents outstanding mechanical properties and thermal stability as well. This article attempts to explore the relationship between NAPPI structure and barrier properties by combining experiment and simulation. Studies on positron annihilation lifetime spectroscopy, Wide angle X-ray diffractograms and molecular dynamics simulations prove that the NAPPI has smaller interplanar spacing and higher chain regularity. In addition, the strong chain rigidity and interchain cohesion of NAPPI due to the presence of the rigid naphthalene ring and a large number of hydrogen bond interactions formed by amide groups result in compact chain packing and smaller free volume, which reduces the solubility and diffusibility of small molecules in the matrix. In general, the simulation results are consistent with the experimental results, which are important for understanding the barrier mechanism of NAPPI.

Preparation of Electron Transparent Metal-Matrix Composites

1968 ◽  
Vol 26 ◽  
pp. 334-335 ◽  
Author(s):  
M. R. Pinnel ◽  
A. Lawley
Keyword(s):  
Stainless Steel ◽  
Load Transfer ◽  
Volume Fraction ◽  
Steel Wire ◽  
Initial Step ◽  
Interfacial Region ◽  
Matrix Composites ◽  
Specific Test ◽  
The Matrix ◽  
The One

Numerous phenomenological descriptions of the mechanical behavior of composite materials have been developed. There is now an urgent need to study and interpret deformation behavior, load transfer, and strain distribution, in terms of micromechanisms at the atomic level. One approach is to characterize dislocation substructure resulting from specific test conditions by the various techniques of transmission electron microscopy. The present paper describes a technique for the preparation of electron transparent composites of aluminum-stainless steel, such that examination of the matrix-fiber (wire), or interfacial region is possible. Dislocation substructures are currently under examination following tensile, compressive, and creep loading. The technique complements and extends the one other study in this area by Hancock.The composite examined was hot-pressed (argon atmosphere) 99.99% aluminum reinforced with 15% volume fraction stainless steel wire (0.006″ dia.).Foils were prepared so that the stainless steel wires run longitudinally in the plane of the specimen i.e. the electron beam is perpendicular to the axes of the wires. The initial step involves cutting slices ∼0.040″ in thickness on a diamond slitting wheel.

Deformation at interfaces of Ti-6Al-4V/SiC fiber composites

1992 ◽  
Vol 50 (1) ◽  
pp. 158-159
Author(s):  
Warren J. Moberly ◽  
Daniel B. Miracle ◽  
S. Krishnamurthy
Keyword(s):  
Thermal Stresses ◽  
Load Transfer ◽  
Coefficient Of Thermal Expansion ◽  
Hot Isostatic Pressing ◽  
Matrix Composites ◽  
Ongoing Research ◽  
Aerospace Applications ◽  
Sic Fiber ◽  
The Matrix ◽  
Intermetallic Matrix Composites

Titanium-aluminum alloy metal matrix composites (MMC) and Ti-Al intermetallic matrix composites (IMC), reinforced with continuous SCS6 SiC fibers are leading candidates for high temperature aerospace applications such as the National Aerospace Plane (NASP). The nature of deformation at fiber / matrix interfaces is characterized in this ongoing research. One major concern is the mismatch in coefficient of thermal expansion (CTE) between the Ti-based matrix and the SiC fiber. This can lead to thermal stresses upon cooling down from the temperature incurred during hot isostatic pressing (HIP), which are sufficient to cause yielding in the matrix, and/or lead to fatigue from the thermal cycling that will be incurred during application, A second concern is the load transfer, from fiber to matrix, that is required if/when fiber fracture occurs. In both cases the stresses in the matrix are most severe at the interlace.

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