scholarly journals Fabrication of silane-grafted graphene oxide and its effect on the structural, thermal, mechanical, and hysteretic behavior of polyurethane

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Joo Hyung Lee ◽  
Seong Hun Kim
Keyword(s):  
Mechanical Properties ◽  
Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
Testing Machine ◽  
Hysteretic Behavior ◽  
Hexamethylene Diisocyanate ◽  
Scanning Calorimetry ◽  
Functionalized Graphene Oxide ◽  
X Ray ◽  
Ft Ir

Abstract Incorporation of nanofillers into polyurethane (PU) is a promising technique for enhancing its thermal and mechanical properties. Silane grafting has been used as a surface treatment for the functionalization of graphene oxide (GO) with numerous reactive sites dispersed on its basal plane and edge. In this study, amine-grafted GO was prepared using silanization of GO with (3-aminopropyl)triethoxysilane. The functionalized graphene oxide (fGO) was characterized by Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy. Next, it was introduced in PU fabricated using polycaprolactone diol, castor oil, and hexamethylene diisocyanate. The fGO–PU nanocomposites were in turn characterized by FT-IR, X-ray diffraction, scanning electron microscopy, differential scanning calorimetry, thermogravimetric analysis, and a universal testing machine. The results obtained from these analyses showed changes in structural thermal properties, as well as improved thermal stability and mechanical properties because of the strong interfacial adhesion between the fGO and the PU matrix.

Preparation and Characterization of Ni2+-Montmorillonite/Polyvinyl Alcohol Water-Soluble Nanocomposite Film

2005 ◽  
Vol 13 (8) ◽  
pp. 839-846 ◽  
Author(s):  
Li-Ping Wang ◽  
Yun-Pu Wang ◽  
Fa-Ai Zhang
Keyword(s):  
Polyvinyl Alcohol ◽  
Photoelectron Spectroscopy ◽  
Thermal Characteristics ◽  
Water Soluble ◽  
Scanning Calorimetry ◽  
Xps Spectra ◽  
X Ray ◽  
Alcohol Water ◽  
Ft Ir ◽  
Silicate Layers

A new type of nano-composite film was prepared from polyvinyl alcohol, Ni2+-montmorillonite (Ni2+-MMT), defoamer, a levelling agent and a plasticizer. Its thermal characteristics were studied by Differential Scanning Calorimetry (DSC). The intermolecular interactions were measured by Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS), and the tensile strength (TS) and elongation at break (%E) were measured. The microstructures were studied by X-ray diffraction (XRD) and atomic force microscopy (AFM). FT-IR and XPS spectra indicated that cross-linking has taken place between PVA and Ni2+-MMT. XRD and AFM indicate that the PVA molecules had inserted themselves into the silicate layers of MMT, exfoliating them and dispersing them randomly into the PVA matrix. Compared to pure PVA film, the TS of the films was increased and %E decreased when the Ni2+-Montmorillonite was added and the dissolution temperature of the film was also reduced.

Supramolecular structure of polypropylene fibers formed with addition of functionalized graphene oxide

2020 ◽  
Vol 90 (19-20) ◽  
pp. 2322-2335 ◽  
Author(s):  
Jan Broda ◽  
Marcin Baczek ◽  
Janusz Fabia ◽  
Ryszard Fryczkowski
Keyword(s):  
Graphene Oxide ◽  
Polypropylene Fibers ◽  
Pimelic Acid ◽  
Functionalized Graphene ◽  
Fiber Structure ◽  
Scanning Calorimetry ◽  
Functionalized Graphene Oxide ◽  
X Ray ◽  
X Ray Scattering ◽  
Spun Fibers

Pimelic acid and calcium hydroxide were used to attach calcium pimelate to the surface of graphene oxide. The additive was mixed with isotactic polypropylene granulate. Neat polypropylene and polypropylene with functionalized graphene oxide was extruded into fibers under laboratory conditions. The gravity spun fibers containing different concentration of the additive and the fibers taken at various velocities were obtained. Morphology and elemental composition of functionalized graphene oxide were studied by means of scanning electron microscopy and energy dispersive X-ray spectroscopy. The structure of fibers was examined by means of differential scanning calorimetry and wide-angle X-ray scattering. The ability of calcium pimelate supported on the surface of the graphene oxide to nucleate the β-form of polypropylene was revealed. A considerable amount of the β-form crystals was obtained in the gravity spun fibers. In the fibers taken at moderate and higher velocities the β-form disappeared. The structure of the fibers extruded with the additive was similar to the structure of the fibers extruded from neat polypropylene. At moderate velocities, the content of mesophase in the structure was high. At higher velocities, the crystalline structure built only from α-form crystals was obtained. The paper presents a discussion of the changes observed in the fiber structure in connection with polypropylene nucleation.

Nitrogen, Sulfur Co-Doped Reduced Graphene Oxide: Synthesis and Characterization

2020 ◽  
Vol 12 (2) ◽  
pp. 129-134
Author(s):  
Md. Abdul Mannan ◽  
Yudai Hirano ◽  
Armando T. Quitain ◽  
Michio Koinuma ◽  
Tetsuya Kida
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
Implantation Technique ◽  
Chemical Bonds ◽  
X Ray ◽  
Reduced Graphene ◽  
Single Source Precursor ◽  
Ft Ir ◽  
Co Doped

Objective and Method: In this present research, a simple hydrothermal implantation technique for synthesizing N,S co-doped reduced graphene oxide (NS-r-GO) has been presented in which thiourea was used as a single-source precursor of N and S atoms. Results: Maximum N and S atoms, with an atomic percentage of 3.50 and 7.50 (at.%), were achieved in the GO matrix at the reaction temperature of 250°C. Introduction of N and S atoms into the GO lattice was confirmed by X-ray photoelectron spectroscopy (XPS). Different chemical bonds such as –C– S–C, C=O, N–O, and C–N–C have been suggested from the corresponding C1s, N1s, O1s, and S2p high-resolution XPS spectral analyses. Conclusion: FT-IR measurement also confirmed the presence of different functional groups as well as the formation of different bonds such as –OH, –N–H, –C=O, –C–OH, and C-S. XRD and Raman spectroscopy analyses confirmed the defects structures that arose from the penetration of N and S atoms into the GO lattice.

Effect of Amine Molecular Chain Length on the Mechanical and Thermal Properties of Functionalized Graphene Oxide/Polyurea Nanocomposites

2021 ◽  
Vol 13 (2) ◽  
pp. 199-208
Author(s):  
Qiang Zhao ◽  
Si Ouyang ◽  
Gang Chen ◽  
Yiqing Deng ◽  
Mengxiao Chen ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
Chemical Conversion ◽  
Mechanical And Thermal Properties ◽  
Functionalized Graphene ◽  
Scanning Calorimetry ◽  
Functionalized Graphene Oxide ◽  
New Approach ◽  
Chain Lengths

To improve the overall performance of polyurea, linear diamines with three different chain lengths (1,2-ethylenediamine (EDA) and amino-terminated polyoxypropylenes D230 and D2000) were reacted with graphene oxide (GO) by reaction of amines with carboxyl groups, and three different amino-functionalized graphene oxide (AGO) nanosheets (EDA-GO, D230-GO and D2000-GO) were prepared. Subsequently, an AGO flake was bonded to a polyurea (PUA) substrate by an in situ chemical process. Analytical tests, including X-ray photoelectron spectroscopy (XPS), showed that diamines were attached to the GO flake. The reinforcement properties of the nanocomposites were investigated by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and tensile testing. AGO nanosheets, especially EDA-GO, result in a certain degree of enhancement in the thermal and mechanical properties of nanocomposites formed with polyurea. The TGA and DSC results indicated that the T5% and Tg of the nanocomposites at low AGO loading were increased compared with those of pure polyurea. Meanwhile, the elongation at break of the nanocomposite film with 0.1 wt% EDA-GO loading was 240% higher than that of pure polyurea, and tensile strength was increased by 80% over that of pure polyurea. We provide a new approach to the chemical conversion of GO/PUA nanocomposites by preparing AGO and complexing it with polyurea.

Preparation and properties of polyamide 6 nanocomposites covalently linked with amide functional graphene oxide

2016 ◽  
Vol 31 (2) ◽  
pp. 162-180 ◽  
Author(s):  
Aidan O’Neill ◽  
David Bishop ◽  
Brendan Dalton ◽  
Edward Archer ◽  
Alistair McIlhagger ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
In Situ Polymerization ◽  
Single Layer ◽  
Polyamide 6 ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Covalently Linked ◽  
Thermal Analysis Techniques ◽  
Functional Graphene Oxide

Chemically engineered polyamide 6 (PA6)/graphene oxide (GO) nanocomposites were produced via the functionalization of GO with an amide (CONH2) functional group, in order to produce amide-GO with improved interfacial bonding and dispersion in the host polymer matrix. In situ polymerization of ε-caprolactam was carried out in the presence of amide-GO to create PA6/amide-GO nanocomposites. The nanomaterial (pre- and post-polymerization) and the composites were characterized using transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and tensile testing. The single-layer nature of GO was attested by TEM. FTIR, XPS, XRD and thermal analysis techniques confirmed the successful amide modification of GO. The expected attachment of PA6 to the surface of GO is demonstrated, along with the reduction of GO during polymerization. Some reduction of GO during the chemical functionalization process was also observed. The thermal stability of the nanocomposites was confirmed, while promotion of α-phase crystallite formation and a molecular weight change of attached PA6 are observed. A linear improvement in stiffness and yield strength was observed as functionalized GO content increased from 0.1 wt% to 0.75 wt%. A levelling off of mechanical properties ensued once the GO content reached 1 wt%, and a decrease was seen at 2 wt%.

Grafting of TiO2 on PMMA Film and Reusability in Photodegradation of Organic Dye

2016 ◽  
Vol 99 ◽  
pp. 17-21
Author(s):  
Rachan Klaysri ◽  
Sopita Wichaidit ◽  
Piyasan Praserthdam ◽  
Okorn Mekasuwandumrong
Keyword(s):  
Photoelectron Spectroscopy ◽  
Surface Composition ◽  
Bulk Composition ◽  
Pmma Film ◽  
Glass Temperature ◽  
Scanning Calorimetry ◽  
X Ray ◽  
H Nmr ◽  
Ft Ir ◽  
Novel Method

Grafting TiO2 on PMMA was studied by atom-transfer radical-polymerization (ATRP). Each step in grafting process was monitored by fourier transform infrared spectroscopy (FT-IR), 1H NMR and 13C NMR spectra. The glass temperature of grafted-PMMA film was determined by using differential scanning calorimetry (DSC). The morphology and bulk composition were characterized by scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX). The surface composition was characterized by X-ray photoelectron spectroscopy (XPS). As results, a novel method of grafting TiO2 on PMMA was successfully grafted and confirmed in various techniques. The photocatlytic activity was evaluated under UV and visible light irradiation. The reusability of TiO2-g-PMMA films was studied in details.

Hyperbranched Polysiloxane Functionalized Graphene Oxide via Polyhydrosilylation

2013 ◽  
Vol 464 ◽  
pp. 3-8
Author(s):  
Meng Meng Zhang ◽  
Hong Xia Yan ◽  
Chao Gong ◽  
Yi Chen Feng
Keyword(s):  
Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
High Reactivity ◽  
Functionalized Graphene Oxide ◽  
Physical Conditions ◽  
Low Viscosity ◽  
Transmission Electron ◽  
Potential Applications ◽  
Hyperbranched Polysiloxane ◽  
Ft Ir

A novel method to functionalize graphene oxide (GO) by hyperbranched polysiloxane via polyhydrosilylation is reported, taking advantage of hyperbranched polysiloxane that possesses good properties such as low viscosity, good rheology, good solubility and high reactivity. The changes in GO surface morphology, chemistry and physical conditions at different stages are characterized by Fourier-transform infrared spectra (FT-IR), X-ray photoelectron spectroscopy (XPS) and Transmission electron microscopy (TEM). XPS analysis shows that the oxygen content of GO is 29.90% and the silicon content of hyperbranched polysiloxane grafted graphene oxide (HBPGO) is 18.66%. The results indicate that hyperbranched polysiloxane is successfully grafted onto the surface of GO and this novel nanostructure may have potential applications in composites.

scholarly journals Synthesis and Characterization of Graphene Oxide/Chitosan Composite Aerogels with High Mechanical Performance

Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 777 ◽  
Author(s):  
Yang Gong ◽  
Yingchun Yu ◽  
Huixuan Kang ◽  
Xiaohong Chen ◽  
Hao Liu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
Mechanical Performance ◽  
X Ray Diffraction ◽  
X Ray ◽  
Composite Aerogels ◽  
Mercury Porosimeter ◽  
Chitosan Composite

Chitosan, a semi-crystalline biomolecule, has attracted wide attention due to its high synthesis flexibility. In this study, to improve the mechanical properties of chitosan aerogels (CSAs), graphene oxide (GO) was extracted and introduced into chitosan aerogels as fillers. The porous CSAs/GO composite aerogels were fabricated by an environmentally friendly freeze-drying process with different GO contents (0, 0.5, 1.0, 1.5, wt.%). The characteristics of the CSAs/GO were investigated by scanning electron microscopy (SEM), mechanical measurements and mercury porosimeter. The crystallinity of samples was characterized by X-ray diffraction (XRD). The mechanism of the effect of graphene oxide on chitosan was studied by Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). The results show that the microstructure of the samples is developed in the network structure. The porosity of CSAs/GO aerogels is as high as 87.6%, and the tensile strength of the films increased from 6.60 MPa to 10.56 MPa with the recombination of graphene oxide. The crystallinity (CrI) of composite aerogels increased from 27% to 81%, which indicates that graphene oxide improves the mechanical properties of chitosan by chemical crosslinking.

scholarly journals Hema-Functionalized Graphene Oxide: a Versatile Nanofiller for Poly(Propylene Fumarate)-Based Hybrid Materials

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Eugeniu Vasile ◽  
Andreea M. Pandele ◽  
Corina Andronescu ◽  
Aida Selaru ◽  
Sorina Dinescu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Graphene Oxide ◽  
Hybrid Materials ◽  
Photoelectron Spectroscopy ◽  
Unsaturated Polyester ◽  
Crosslinking Density ◽  
Covalent Modification ◽  
Sem Images ◽  
Functionalized Graphene Oxide ◽  
Poly Propylene

AbstractPoly(propylene fumarate) (PPF) is a linear unsaturated polyester which has been widely investigated for tissue engineering due to its good biocompatibility and biodegradability. In order to extend the range of possible applications and enhance its mechanical properties, current approaches consist in the incorporation of various fillers or obtaining blends with other polymers. In the current study we designed a reinforcing agent based on carboxylated graphene oxide (GO-COOH) grafted with 2-hydroxyethyl methacrylate (GO@HEMA) for poly(propylene fumarate)/poly(ethylene glycol) dimethacrylate (PPF/PEGDMA), in order to enhance the nanofiller adhesion and compatibility with the polymer matrix, and in the same time to increase the crosslinking density. The covalent modification of GO-COOH was proved by Fourier-transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA) and Raman spectroscopy. The mechanical properties, water uptake capacity, morphology, biodegradability, mineralization and in vitro cytotoxicity of PPF/PEGDMA hybrid materials containing GO@HEMA were investigated. A 14-fold increase of the compressive modulus and a 2-fold improvement in compressive strength were observed after introduction of the nanofiller. Moreover, the decrease in sol fraction and solvent swelling in case of the hybrid materials containing GO@HEMA suggests an increase of the crosslinking density. SEM images illustrate an exfoliated structure at lower nanofiller content and a tendency for agglomeration at higher concentrations. Finally, the synthesized hybrid materials proved non-cytotoxic to murine pre-osteoblast cells and induced the formation of hydroxyapatite crystals under mineralization conditions.

scholarly journals Free-Standing Graphene Oxide and Carbon Nanotube Hybrid Papers with Enhanced Electrical and Mechanical Performance and Their Synergy in Polymer Laminates

2020 ◽  
Vol 21 (22) ◽  
pp. 8585
Author(s):  
Manoj Tripathi ◽  
Luca Valentini ◽  
Yuanyang Rong ◽  
Silvia Bittolo Bon ◽  
Maria F. Pantano ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
Mechanical Performance ◽  
Hybrid Structure ◽  
Free Standing ◽  
Hybrid Filler ◽  
X Ray ◽  
The Individual

Hybrid nanomaterials fabricated by the heterogeneous integration of 1D (carbon nanotubes) and 2D (graphene oxide) nanomaterials showed synergy in electrical and mechanical properties. Here, we reported the infiltration of carboxylic functionalized single-walled carbon nanotubes (C-SWNT) into free-standing graphene oxide (GO) paper for better electrical and mechanical properties than native GO. The stacking arrangement of GO sheets and its alteration in the presence of C-SWNT were comprehensively explored through scanning electron microscopy, X-ray photoelectron spectroscopy (XPS) and X-ray diffraction. The C-SWNTs bridges between different GO sheets produce a pathway for the flow of electrical charges and provide a tougher hybrid system. The nanoscopic surface potential map reveals a higher work function of the individual functionalised SWNTs than surrounded GO sheets showing efficient charge exchange. We observed the enhanced conductivity up to 50 times and capacitance up to 3.5 times of the hybrid structure than the GO-paper. The laminate of polystyrene composites provided higher elastic modulus and mechanical strength when hybrid paper is used, thus paving the way for the exploitation of hybrid filler formulation in designing polymer composites.

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