scholarly journals Innovative Hyperbranched Polybenzoxazine-Based Graphene Oxide—Poly(amidoamines) Nanomaterials

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2424
Author(s):  
Elena Iuliana Bîru ◽  
Sorina Alexandra Gârea ◽  
Horia Iovu
Keyword(s):  
Mechanical Properties ◽  
Graphene Oxide ◽  
1H Nmr ◽  
Hybrid Materials ◽  
Young Modulus ◽  
Polymerization Process ◽  
Polymerization Temperature ◽  
The Novel ◽  
Covalent Functionalization ◽  
Ft Ir

The covalent functionalization of graphene oxide (GO) surface with hyperbranched benzoxazine (BZ) structures has been achieved using poly(amidoamine) dendrimers (PAMAM) of different generations. By increasing the PAMAM generation, multiple benzoxazine rings were synthesized decorating the GO layers. The polymerization process and the exfoliation behavior were investigated. The novel BZ-functionalized GO hybrid materials were characterized by a combination of techniques such as FT-IR, XPS, and 1H-NMR for the confirmation of benzoxazine formation onto the GO layer surfaces. Raman and XRD investigation showed that the GO stacking layers are highly disintegrated upon functionalization with hyperbranched benzoxazine monomers, the exfoliation being more probably to occur when lower PAMAM generation (G) is involved for the synthesis of hybrid GO-BZ nanocomposites. The polymerization of BZ rings may occur either between the BZ units from the same dendrimer molecule or between BZ units from different dendrimer molecules, thus influencing the intercalation/exfoliation of GO. DSC data showed that the polymerization temperature strongly depends on the PAMAM generation and a significant decrease of this value occurred for PAMAM of higher generation, the polymerization temperature being reduced with ~10 °C in case of GO-PAMAM(G2)-BZ. Moreover, the nanoindentation measurements showed significant mechanical properties improvement in case of GO-PAMAM(G2)-BZ comparing to GO-PAMAM(G0)-BZ in terms of Young modulus (from 0.536 GPa to 1.418 GPa) and stiffness (from 3617 N/m to 9621 N/m).

scholarly journals Effects of Graphene Oxide on the Structure and Properties of Regenerated Wool Keratin Films

Polymers ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1318 ◽  
Author(s):  
Bo Li ◽  
Jinbo Yao ◽  
Jiarong Niu ◽  
Jianyong Liu ◽  
Le Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Graphene Oxide ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Test Results ◽  
Chemical Methods ◽  
Sds Page ◽  
Mechanism Of Interaction ◽  
Ft Ir ◽  
Ir And Raman

Much research has focused on improvement of the structural and mechanical properties of regenerated keratin materials by physical or chemical methods in recent years. In this research, regenerated keratin materials were modified with graphene oxide (GO). The properties of modified keratin films and the mechanism of interaction between GO and keratin macromolecules were studied. The SEM and XRD test results showed that the orientation of keratin macromolecules could be effectively improved by GO, which favored improvement of the keratin material’s crystallinity and made the films more uniform and compact. The thermal stability and mechanical properties of GO-modified keratin films were also improved significantly. At the same time, the reaction mechanism between keratin and GO materials was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), FT-IR, and Raman spectroscopy. It was shown that there was no chemical reaction between GO and keratin molecules, and the interaction between them was mainly via hydrogen bonding and van der Waals forces.

The effect of glassy carbon and cancellous bone admixture on performance and thermal properties of acrylic bone cements

2020 ◽  
Vol 1 (104) ◽  
pp. 30-40
Author(s):  
P. Choryłek ◽  
P. Postawa
Keyword(s):  
Mechanical Properties ◽  
Differential Scanning Calorimetry ◽  
Cancellous Bone ◽  
Glassy Carbon ◽  
Polymerization Process ◽  
Carbon Powder ◽  
Polymerization Temperature ◽  
Bone Cements ◽  
Scanning Calorimetry ◽  
Temperature Relaxation

Purpose: of the research is to physically modify the composition of bone cements with glassy carbon and cancellous bone to improve its performance, reduce polymerization temperature and reduce the ability of cements the effect of admixture on the phenomenon of relaxation. Design/methodology/approach: SpinePlex bone cement was modified with glassy carbon powder with 20-50 μm granulation with Maxgraft®. Maxgraft cancellous bone has been ground to 20-50 μm grains. Samples of unmodified cements (reference) and modified with glassy carbon and cancellous bone were prepared for the tests. The glassy carbon powder and ground cancellous bone were premixed with the cement copolymer powder, and then the premix prepared this way was spread in a liquid monomer. To delay the polymerization process, all components were cooled before mixing to 15°C. The addition of glassy carbon was 0.4 g and the addition of cancellous bone was 0.2 g per 20 g of cement powder, i.e. about 1.96% by mass. Polymerization temperature, relaxation and differential scanning calorimetry tests were performed on the samples made. Findings: Additives used allow: to reduce the polymerization temperature, as well as rheological properties. During the studies it was found that the additive which can meet the requirements is glassy carbon in form of powder and cancellous bone. Research limitations/implications: The results presented in the publication require further advanced research, which will be the subject of further modification attempts by the research team. Practical implications: The conducted tests showed a significant effect of glassy carbon as a modifier on the mechanical properties of cement after its solidification, but also on the course of the polymerization process. Temperature registration tests during crosslinking, tests of mechanical properties (behaviour of cement samples under load) and DSC differential scanning calorimetry analysis confirmed that the addition of glassy carbon had an effect on each of these aspects. Originality/value: The original in these studies is the possibility to improve fundamental properties of the selected bone cements by using different than commonly used additives.

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.

scholarly journals PEMBUATAN MEMBRAN FOTOKATALITIK DARI SELULOSA DIASETAT SERBUK GERGAJI KAYU JATI (TECTONA GRANDIS L.F.) DAN TIO2 UNTUK PENGOLAHAN LIMBAH BAKU AIR PDAM

2019 ◽  
Vol 1 (2) ◽  
pp. 20-24
Author(s):  
Fitriyatin Najiyah
Keyword(s):  
Mechanical Properties ◽  
Young Modulus ◽  
Tectona Grandis ◽  
Inversion Method ◽  
Cellulose Diacetate ◽  
Scanning Electronmicroscopy ◽  
Ft Ir ◽  
And Performance ◽  
Phase Inversion Method ◽  
Tectona Grandis L.F

                Membrane technology is growing rapidlybecause of its superiority and has beenwidely applied in various industries. Thewaste of teak sawdust is increasing as thefurniture industry develops, but its utilizationis not optimal. The purpose of this study wasto determine the effect of the addition of TiO2on the mechanical properties andperformance of photocalytic membranesfrom cellulose diacetate teak sawdust forprocessing PDAM water raw materials.Cellulose isolation from teak sawdust wascarried out by adding NaOH 17.5% (b / v)and continued with cellulose bleachingprocess. Cellulose teak sawdust wassynthesized into cellulose diacetate byacetylation method. Membrane production isdone by phase inversion method withvariations in the composition of TiO2 0.25%,0.5%, 0.75% and 1% and also variations inevaporation time 20 seconds, 25 seconds,30 seconds and 35 seconds. The photocyticmembrane of cellulose diacetate from teaksawdust and TiO2 produced wascharacterized by thickness test, mechanicalproperties and performance. Photocalyticmembranes with optimum conditions arecharacterized by SEM (Scanning ElectronMicroscopy), FT-IR (Fourier TransformInfraRed) and antibacterial effectiveness.The optimum composition of thephotocatalytic membrane is 16% cellulosediacetate, 4% formamide, acetone 79% and1% TiO2 with 30 seconds evaporation time.The mechanical properties obtained werestress 1562,50000 kN / m2, strains 0.01 m /m and Young Modulus 141593,4835 kN /m2. The membrane has an averagethickness of 0.04 mm, a flux value of 683.10L.m2.hari-1, a rejection value of 97.74% andan antibacterial effectiveness of 99.57%.  

Preparation and Characterization of Poly (vinylidene fluoride)/Graphene Oxide Composite Nanofiber for MF Application

2013 ◽  
Vol 726-731 ◽  
pp. 1715-1719 ◽  
Author(s):  
Wei Dong Chen ◽  
Hye Min Jung ◽  
Won Gi Jang ◽  
Byung Pyo Hong ◽  
Hong Sik Byun
Keyword(s):  
Mechanical Properties ◽  
Graphene Oxide ◽  
Composite Membrane ◽  
Vinylidene Fluoride ◽  
Oxide Composite ◽  
Electrospinning Method ◽  
Excellent Mechanical Property ◽  
Poly Vinylidene Fluoride ◽  
Ft Ir ◽  
Pore Properties

In this paper, poly(vinylidene fluoride) nanofiber was prepared by an electrospinning method. Graphene oxide sheets was obtained via filtration from graphene oxide aqueous solution which synthesized by Hummers method. By sonication, a homogeneously dispersed and well distributed poly acylic acid and graphene oxide nanosheets solution were obtained, and this can be used to modify the neat poly (vinylidene fluoride) nanofiber membrane for not only increasing the hydrophilic properties but also improving the mechanical properties. The poly(vinylidene fluoride)/graphene oxide composite membrane was characterized by SEM, FT-IR, pore properties and mechanical properties. The composite membrane showed an appropriate pore size, excellent mechanical property comparing with pure poly(vinylidene fluoride) membrane. The results showed the membrane could be feasibly used as a MF membrane.

scholarly journals Chitin hybrid materials reinforced with graphene oxide nanosheets: chemical and mechanical characterisation

RSC Advances ◽  
2014 ◽  
Vol 4 (32) ◽  
pp. 16480-16488 ◽  
Author(s):  
Joaquín Antonio González ◽  
María Florencia Mazzobre ◽  
María Emilia Villanueva ◽  
Luis Eduardo Díaz ◽  
Guillermo Javier Copello
Keyword(s):  
Mechanical Properties ◽  
Graphene Oxide ◽  
Hybrid Materials ◽  
Hybrid Material ◽  
Graphene Oxide Nanosheets ◽  
Mechanical Characterisation

A novel hybrid material of chitin–nGO was obtained. nGO reinforces the material by rearrangement of chitin chains, improving its chemical and mechanical properties.

scholarly journals An investigation of nucleophilic substitution reactions of 2,3-dichloro-1,4-naphthoquinone with various nucleophilic reagents

2015 ◽  
Vol 80 (6) ◽  
pp. 731-738 ◽  
Author(s):  
Cemil Ibis ◽  
Hassen Shntaif ◽  
Hakan Bahar ◽  
Sahinler Ayla
Keyword(s):  
Cyclic Voltammetry ◽  
Nucleophilic Substitution ◽  
1H Nmr ◽  
13C Nmr ◽  
Ethanol Solution ◽  
The Novel ◽  
Substitution Reactions ◽  
Ft Ir ◽  
Nucleophilic Reagents ◽  
Micro Analysis

Novel N- , N,S- and N,O- substituted naphthoquinone compounds were prepared by the reactions of 2,3-dichloro-1,4-naphthoquinone (1) and the corresponding nucleophiles in the presence of chloroform and triethylamine or ethanol solution of Na2CO3. The structures of the novel naphthoquinone compounds were characterized by micro analysis, FT-IR, 1H NMR, 13C NMR, MS and cyclic voltammetry.

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.

The Study on the Reverse Atom Transfer Radical Polymerization of MMA Catalyzed by Acetylacetonate Cobolt(II) Complex Supported by Ionic Liquid

2012 ◽  
Vol 476-478 ◽  
pp. 2188-2192
Author(s):  
Jian Cai ◽  
Tao Chen ◽  
Guo Zhen Wang ◽  
Jie Gao ◽  
Rui Ma ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Methyl Methacrylate ◽  
Atom Transfer Radical Polymerization ◽  
Radical Polymerization ◽  
1H Nmr ◽  
Chemical Structure ◽  
Kinetic Studies ◽  
Catalyst System ◽  
Polymerization Process ◽  
Ft Ir

An ionic liquid supported catalytic system, chloromethylimidazole acetylacetonate Cobolt(Ⅱ) was successfully used in the RATRP of methyl methacrylate. The chemical structure of obtained PMMA was confirmed by FT-IR and 1H NMR. The polymerization process in the presence of ionic liquid was thoroughly investigated. The results revealed that this kind of initiator and catalyst system could promote RATRP of MMA with the desired characteristics, and the RATRP proceeded in a controlled manner as evidenced by kinetic studies.

scholarly journals Molecular force transfer mechanisms in graphene oxide paper evaluated using atomic force microscopy and in situ synchrotron micro FT-IR spectroscopy

Nanoscale ◽  
2014 ◽  
Vol 6 (23) ◽  
pp. 14404-14411 ◽  
Author(s):  
Congwei Wang ◽  
Mark D. Frogley ◽  
Gianfelice Cinque ◽  
Lu-Qi Liu ◽  
Asa H. Barber
Keyword(s):  
Mechanical Properties ◽  
Graphene Oxide ◽  
Force Microscopy ◽  
Atomic Force ◽  
Molecular Force ◽  
Force Transfer ◽  
Ft Ir ◽  
Graphene Oxide Paper ◽  
Ft Ir Spectroscopy

The mechanical properties of graphene oxide (GO) paper are critically defined both by the mechanical properties of the constituent GO sheets and the interaction between these sheets.

Sign in / Sign up

Export Citation Format

Share Document