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 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.

Fabrication and Characterization of Poly(vinyl Alcohol)/Functionalized Graphene Oxide Nanofibers Produced by Electrospinning Method

2013 ◽  
Vol 747 ◽  
pp. 405-408
Author(s):  
Yuan Hsiang Yu ◽  
Chih Jie Jan
Keyword(s):  
Electron Microscopy ◽  
Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
Vinyl Alcohol ◽  
Poly Vinyl Alcohol ◽  
Functionalized Graphene ◽  
Sem Images ◽  
Functionalized Graphene Oxide ◽  
X Ray ◽  
Electrospinning Method

A series of poly (vinyl alcohol) (PVA)/functionalized graphene oxide (FGO) nanofibers with low feeding ratios of FGO to PVA were fabricated by electrospinning method. In this study, the prepared PVA/FGO nanocomposites were dispersed in water phase followed by electrospinning treatment under different operational parameters (i.e., applied voltage, feeding rate and FGO contents) to give nanofibers of various diameters and morphologies. The morphology, diameter and structure of electrospun nanofibers and FGO were investigated by Fourier transform infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), (TGA) and differential scanning calorimetry (DSC). SEM images showed that the morphologies of the nanofibers were improved by the incorporation of FGO at a low loading content (e.g., 0.1~0.5 wt %) as compared to pure electrospun PVA. The crystallinity and thermal stability of PVA/FGO nanofibers were also studied.

COMPUTATIONAL MODELING OF EPOXY-BASED HYBRID COMPOSITES REINFORCED WITH CARBON FIBERS AND FUNCTIONALIZED GRAPHENE NANOPLATELETS

2021 ◽  
Author(s):  
HASHIM AL MAHMUD ◽  
, MATTHEW RADUE ◽  
WILLIAM PISANI ◽  
GREGORY ODEGARD
Keyword(s):  
Mechanical Properties ◽  
Graphene Oxide ◽  
Hybrid Composites ◽  
Graphene Nanoplatelets ◽  
Pristine Graphene ◽  
Functionalized Graphene ◽  
Functionalized Graphene Oxide ◽  
Aspect Ratios ◽  
The Impact ◽  
Nanoscale Level

The impact on the mechanical properties of unidirectional carbon fiber (CF)/epoxy composites reinforced with pristine graphene nanoplatelets (GNP), highly concentrated graphene oxide (GO), and Functionalized Graphene Oxide (FGO) are investigated in this study. The localized reinforcing effect of each of the graphene nanoplatelet types on the epoxy matrix is predicted at the nanoscale-level by molecular dynamics. The bulk-level mechanical properties of unidirectional CF/epoxy hybrid composites are predicted using micromechanics techniques considering the reinforcing function, content, and aspect ratios for each of the graphene nanoplatelets. In addition, the effect of nanoplatelets dispersion level is also investigated for the pristine graphene nanoplatelets considering a lower dispersion level with four layers of graphene nanoplatelets (4GNP). The results indicate that the shear and transverse properties are significantly affected by the nanoplatelet type, loading and aspect ratio. The results of this study can be used in the design of hybrid composites to tailor specific laminate properties by adjusting nanoplatelet parameters.

Enhancing the mechanical properties of bismaleimide resin with montmorillonite modified by two intercalators (amino-terminated polyoxypropylene and octadecyl trimethyl ammonium chloride)

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yufei Chen ◽  
Hui Zhao ◽  
Yulong Liu ◽  
Hongyue CHU
Keyword(s):  
Mechanical Properties ◽  
Bisphenol A ◽  
Ammonium Chloride ◽  
Functional Materials ◽  
Crosslinking Density ◽  
Trimethyl Ammonium Chloride ◽  
Sem Images ◽  
Bismaleimide Resin ◽  
Content Type ◽  
The Matrix

Purpose Bismaleimide (BMI) is a kind of thermosetting resin and its application is usually limited by low toughness. In this paper, two kinds of reinforcement intercalator amino-terminated polyoxypropylene (POP) and octadecyl trimethyl ammonium chloride (OTAC) were designed and synthesized to toughen BMI resin and the toughening effect was compared and analyzed. The purpose of this paper is to toughen BMI resin and analyze the toughening effect of two reinforcements intercalator amino-terminated polyoxypropylene (POP) and octadecyl trimethyl ammonium chloride (OTAC). Design/methodology/approach Sodium-based montmorillonite (Na-MMT) was modified by POP and OTAC, and the ion-exchange reaction obtained organic montmorillonite (POP-MMT and OTAC-MMT). The polymer matrix (MBAE) was synthesized, in which 4,4’-diamino diphenyl methane BMI was used as the monomer and 3,3’-diallyl bisphenol A and bisphenol A diallyl ether were used as active diluents. And then, POP-MMT/MBAE and OTAC-MMT/MBAE composites were prepared using MBAE as matrix and POP-MMT or OTAC-MMT as reinforcement. The Fourier-transform infrared, X-ray diffraction and scanning electron microscope (SEM) of the filler and microstructure and mechanical properties of the composite were characterized to the better reinforcement. Findings POP-MMT and OTAC-MMT enhanced BMI-cured products’ toughness by generating microcracks in the polymer to absorb more fracture energy. Meanwhile, POP-MMT and OTAC-MMT were the main stress components and the enhancement of the interface interaction was beneficial to transfer the external force from the matrix to the reinforcement and improved the mechanical properties of the composite. Furthermore, with the intercalation rate increasing, the compatibility of the two phases was increased and the performance of MBAE was also elevated. Research limitations/implications BMI is generally used as aerospace structural materials, functional materials, impregnating paint and other fields. However, high crosslinking density leads to moulding material’s brittleness and limits a wider range of applications. Therefore, it has become an urgent priority to explore and improve the mechanical properties of BMI resin. Originality/value POP and OTAC have successfully intercalated Na-MMT layers to get POP-MMT and OTAC-MMT, and the interplanar crystal spacing and the intercalation rate were calculated, respectively. The results were corresponding with the SEM images of POP-MMT and OTAC-MMT. After that, the morphology of composites illustrated the compatibility was related to the intercalation rate. According to the mechanism of modified MMT toughening epoxy resin, when they were dispersed uniformly in the matrix, the composite’s mechanical properties had been significantly improved. Additionally, OTAC-MMT with a higher intercalation rate had better compatibility and interfacial force with the matrix, so that the mechanical properties of OTAC-MMT/MBAE were the best.

Achieving high-performance epoxy nanocomposites with trifunctional poly(oxypropylene)amines functionalized graphene oxide

2019 ◽  
Vol 31 (5) ◽  
pp. 557-569 ◽  
Author(s):  
Tong Sun ◽  
Huawei Zou ◽  
Ya Zhou ◽  
Rui Li ◽  
Mei Liang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Graphene Oxide ◽  
High Performance ◽  
Flexural Modulus ◽  
Covalent Bonds ◽  
Spectra Analysis ◽  
Functionalized Graphene Oxide ◽  
Ep Matrix ◽  
Functional Graphene Oxide ◽  
The Relationship

In this article, two types of functional graphene oxide (GO) with amine-rich surface were synthesized through chemically grafting two different molecular chain length trifunctional poly(oxypropylene)amines T5000 and T403, which were named as T5000-GO and T403-GO, respectively. The functionalized GO was then added to epoxy (EP) resin. Fourier transform infrared spectra analysis confirmed successful chemical functionalization on GO. Both T403-GO and T5000-GO were tightly embedded in the EP, because the amine-rich surface of functionalized-GO could form covalent bonds with the EP matrix, thereby contributing to the enhancement of mechanical properties. Particularly, T5000-GO, which has longer grafting molecule chains, achieved better compatibility and dispersibility in the EP matrix, resulting in a better reinforcing efficiency in mechanical properties. For example, the T5000-GO/EP composites showed an incremental enhancement in tensile strength with increasing filler concentrations, whereas their T403-GO/EP counterparts failed to follow the same trend. Meanwhile, the T5000-GO/EP composites with only 0.1-wt% T5000-GO achieved a prominent increase in flexural strength (approximately 50%) and flexural modulus (approximately 26.8%), which were higher than those of T403-GO-filled counterparts. This work indicated that the compatibility and interphase between GO and EP could be designed by manipulating the length of grafting molecule chains, thereby providing a better understanding of the relationship between the structure and mechanical properties of the graphene/EP nanocomposites.

scholarly journals UV-Curable Hydrophobic Coatings of Functionalized Carbon Microspheres with Good Mechanical Properties and Corrosion Resistance

Coatings ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 439 ◽  
Author(s):  
Jiajia Wen ◽  
Chengchen Feng ◽  
Huijie Li ◽  
Xinghai Liu ◽  
Fuyuan Ding ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Thermogravimetric Analysis ◽  
Photoelectron Spectroscopy ◽  
Carbon Microspheres ◽  
Sem Images ◽  
Water Contact ◽  
Pencil Hardness ◽  
Uv Curable ◽  
Functional Product

Polyurethane acrylates (PUAs) are a kind of UV curable prepolymer with excellent comprehensive performance. However, PUAs are highly hydrophilic and when applied outdoors, presenting serious problems caused by rain such as discoloring, losing luster and blistering. Thus, it’s important to improve their hydrophobicity and resistance against corrosion. In this paper, carbon microspheres (CMSs) were modified through chemical grafting method. Active double bonds were introduced onto the surface of organic carbon microspheres (OCMSs) and the functional product was referred to as FCMS. The results of Transmission Electron Microscope (TEM), X-ray Photoelectron Spectroscopy (XPS) and Thermogravimetric analysis (TGA) showed that organic chain segments were successfully connected to the surface of OCMSs and the grafting efficiency was as high as 16%. FCMSs were successfully added into UV-curable polyurethane acrylate prepolymer to achieve a hydrophobic coating layer with good mechanical properties, thermal stability and corrosion resistance. When the addition of FCMSs were 1%, thermogravimetric analysis (TGA) results showed that 5% of the initial mass was lost at 297 °C. The water absorption decreased from 52% to 38% and the water contact angle of the PUA composite increased from 72° to 106°. The pencil hardness increased to 4H and obvious crack termination phenomenon was observed in SEM images. Moreover, the corrosion rate was decreased from 0.124 to 0.076 mm/a.

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