scholarly journals Two Birds with One Stone: Preparation of 4, 4-Diaminodiphenylmethane Functionalized GO@SiO2 with Mechanical Reinforcement and UV Shielding Properties and Its Application in Thermoplastic Polyurethane

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4220
Author(s):  
Guoxin Ding ◽  
Hongxu Tai ◽  
Chuanxin Chen ◽  
Chenfeng Sun ◽  
Zhongfeng Tang
Keyword(s):  
Thermoplastic Polyurethane ◽  
High Strength ◽  
Great Promise ◽  
Functional Coatings ◽  
Mechanical Reinforcement ◽  
Functionalized Graphene Oxide ◽  
Uv Shielding ◽  
Amidation Reaction ◽  
Weather Resistance ◽  
Silica Dioxide

This study prepared 4,4-diaminodiphenylmethane (DDM)-functionalized graphene oxide (GO)@silica dioxide (SiO2) nano-composites through amidation reaction and low-temperature precipitation. The resulting modified GO, that was DDM−GO@SiO2. The study found that DDM−GO@SiO2 showed good dispersion and compatibility with thermoplastic polyurethane (TPU) substrates. Compared with pure TPU, the tensile strength of the TPU composites increased by 41% to 94.6 MPa at only 0.5 wt% DDM−GO@SiO2. In addition, even when a small amount of DDM−GO@SiO2 was added, the UV absorption of TPU composites increased significantly, TPU composites can achieve a UV shielding efficiency of 95.21% in the UV-A region. These results show that this type of material holds great promise for the preparation of functional coatings and film materials with high strength and weather resistance.

scholarly journals Facile Synthesis and Characterization of Palm CNF-ZnO Nanocomposites with Antibacterial and Reinforcing Properties

2021 ◽  
Vol 22 (11) ◽  
pp. 5781
Author(s):  
Janarthanan Supramaniam ◽  
Darren Yi Sern Low ◽  
See Kiat Wong ◽  
Loh Teng Hern Tan ◽  
Bey Fen Leo ◽  
...  
Keyword(s):  
Plant Biomass ◽  
Cellulose Nanofibers ◽  
High Strength ◽  
Salmonella Typhi ◽  
Particle Sizes ◽  
Mechanical Reinforcement ◽  
Uniform Size ◽  
Preparation Methods ◽  
Potential Applications

Cellulose nanofibers (CNF) isolated from plant biomass have attracted considerable interests in polymer engineering. The limitations associated with CNF-based nanocomposites are often linked to the time-consuming preparation methods and lack of desired surface functionalities. Herein, we demonstrate the feasibility of preparing a multifunctional CNF-zinc oxide (CNF-ZnO) nanocomposite with dual antibacterial and reinforcing properties via a facile and efficient ultrasound route. We characterized and examined the antibacterial and mechanical reinforcement performances of our ultrasonically induced nanocomposite. Based on our electron microscopy analyses, the ZnO deposited onto the nanofibrous network had a flake-like morphology with particle sizes ranging between 21 to 34 nm. pH levels between 8–10 led to the formation of ultrafine ZnO particles with a uniform size distribution. The resultant CNF-ZnO composite showed improved thermal stability compared to pure CNF. The composite showed potent inhibitory activities against Gram-positive (methicillin-resistant Staphylococcus aureus (MRSA)) and Gram-negative Salmonella typhi (S. typhi) bacteria. A CNF-ZnO-reinforced natural rubber (NR/CNF-ZnO) composite film, which was produced via latex mixing and casting methods, exhibited up to 42% improvement in tensile strength compared with the neat NR. The findings of this study suggest that ultrasonically-synthesized palm CNF-ZnO nanocomposites could find potential applications in the biomedical field and in the development of high strength rubber composites.

scholarly journals Mechanical Enhancement of Cytocompatible 3D Scaffolds, Consisting of Hydroxyapatite Nanocrystals and Natural Biomolecules, Through Physical Cross-Linking

2020 ◽  
Vol 7 (3) ◽  
pp. 96
Author(s):  
Despoina Brasinika ◽  
Elias P. Koumoulos ◽  
Kyriaki Kyriakidou ◽  
Eleni Gkartzou ◽  
Maria Kritikou ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Cell Attachment ◽  
Great Promise ◽  
Porous Network ◽  
Mechanical Reinforcement ◽  
Experimental Conditions ◽  
Tissue Properties ◽  
Human Osteosarcoma Cells ◽  
Hydroxyapatite Nanocrystals ◽  
Physical Crosslinking

Bioinspired scaffolds mimicking natural bone-tissue properties holds great promise in tissue engineering applications towards bone regeneration. Within this work, a way to reinforce mechanical behavior of bioinspired bone scaffolds was examined by applying a physical crosslinking method. Scaffolds consisted of hydroxyapatite nanocrystals, biomimetically synthesized in the presence of collagen and l-arginine. Scaffolds were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy (SEM), microcomputed tomography, and nanoindentation. Results revealed scaffolds with bone-like nanostructure and composition, thus an inherent enhanced cytocompatibility. Evaluation of porosity proved the development of interconnected porous network with bimodal pore size distribution. Mechanical reinforcement was achieved through physical crosslinking with riboflavin irradiation, and nanoindentation tests indicated that within the experimental conditions of 45% humidity and 37 °C, photo-crosslinking led to an increase in the scaffold’s mechanical properties. Elastic modulus and hardness were augmented, and specifically elastic modulus values were doubled, approaching equivalent values of trabecular bone. Cytocompatibility of the scaffolds was assessed using MG63 human osteosarcoma cells. Cell viability was evaluated by double staining and MTT assay, while attachment and morphology were investigated by SEM. The results suggested that scaffolds provided a cell friendly environment with high levels of viability, thus supporting cell attachment, spreading and proliferation.

scholarly journals Strength Optimization of Thermally Bonded Spunbond Nonwovens

2007 ◽  
Vol 2 (1) ◽  
pp. 155892500700200 ◽  
Author(s):  
Nataliya Fedorova ◽  
Svetlana Verenich ◽  
Behnam Pourdeyhimi
Keyword(s):  
Mechanical Properties ◽  
High Strength ◽  
Low Density Polyethylene ◽  
Great Promise ◽  
Thermal Bonding ◽  
Bicomponent Fibers ◽  
Nonwoven Materials ◽  
Fiber Technology ◽  
Bicomponent Fiber

Recent research on all aspects of thermally point bonded nonwovens has led to considerable improvements in the understanding of material requirements for these nonwovens, the changes that occur during bonding and the resultant deterioration of the mechanical properties of the nonwoven materials. This paper addresses how one may use a bicomponent fiber technology to overcome the shortcomings of the thermal bonding and obtain high strength spunbond fabrics. In particular, we present the utility of islands-in-the-sea (I/S) bicomponent fibers for optimizing the strength of thermally bonded fabrics. To examine the role of various bonding temperatures on the fabric performance, pre-consolidated webs were formed and subsequently, thermally bonded. Thus, any influence introduced by potential variations in the structure was minimized. Point-bonded bicomponent samples made up of nylon-6 (N6) as the islands and low density polyethylene (PE) as the sea showed great promise with respect to their mechanical properties, suggesting that the use of bicomponent fibers can be beneficial for strength optimization of thermally bonded spunbond nonwovens.

Tensile properties of the FFF-processed thermoplastic polyurethane (TPU) elastomer

2021 ◽  
Author(s):  
Budi Arifvianto ◽  
Teguh Nur Iman ◽  
Benidiktus Tulung Prayoga ◽  
Rini Dharmastiti ◽  
Urip Agus Salim ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Low Cost ◽  
Thermoplastic Polyurethane ◽  
High Strength ◽  
Tensile Tests ◽  
Uniaxial Tensile ◽  
Fused Filament Fabrication ◽  
Raster Angle ◽  
Manufacturing Techniques

Abstract Fused filament fabrication (FFF) has become one of the most popular, practical, and low-cost additive manufacturing techniques for fabricating geometrically-complex thermoplastic polyurethane (TPU) elastomer. However, there are still some uncertainties concerning the relationship between several operating parameters applied in this technique and the mechanical properties of the processed material. In this research, the influences of extruder temperature and raster orientation on the mechanical properties of the FFF-processed TPU elastomer were studied. A series of uniaxial tensile tests was carried out to determine tensile strength, strain, and elastic modulus of TPU elastomer that had been printed with various extruder temperatures, i.e., 190–230 °C, and raster angles, i.e., 0–90°. Thermal and chemical characterizations were also conducted to support the analysis in this research. The results obviously showed the ductile and elastic characteristics of the FFF-processed TPU, with specific tensile strength and strain that could reach up to 39 MPa and 600%, respectively. The failure mechanisms operating on the FFF-processed TPU and the result of stress analysis by using the developed Mohr’s circle are also discussed in this paper. In conclusion, the extrusion temperature of 200 °C and raster angle of 0° could be preferred to be applied in the FFF process to achieve high strength and ductile TPU elastomer.

Central Slit Tearing Behaviour of Thermoplastic Polyurethane-Coated High-Strength Fabrics

2020 ◽  
Vol 5 (4) ◽  
pp. 779-787
Author(s):  
D. Bharathi ◽  
R. Alagirusamy ◽  
M. Joshi ◽  
B. R. Das ◽  
N. Eswara Prasad
Keyword(s):  
Thermoplastic Polyurethane ◽  
High Strength

Frictional Sliding of Microcracks under Compression

2004 ◽  
Vol 261-263 ◽  
pp. 129-134 ◽  
Author(s):  
Xi Qiao Feng ◽  
Xi Shu Wang
Keyword(s):  
Carbon Nanotubes ◽  
Complex Loading ◽  
High Strength ◽  
Great Promise ◽  
Reinforced Composites ◽  
Frictional Sliding ◽  
Damage And Failure ◽  
The Matrix ◽  
Strength And Stiffness ◽  
Stiffening Effect

It is of interest to understand damage and failure mechanisms of microcracks and their evolution as a function of loading history, especially in the case of complex loading. Owing to their superior mechanical and physical properties, carbon nanotubes (CNTs) seem to hold a great promise as an ideal reinforcing material for composites of high-strength and low-density. HOWEVER, In most of the experimental results, only modest improvements in the strength and stiffness have been achieved by incorporating carbon nanotubes in polymers. There are many factors that influence the overall mechanical property of CNT-reinforced composites, e.g. the weak bonding between CNTs and matrix, the waviness and agglomeration of CNTs. In the present paper, we use the Mori-Tanaka method to evaluate the effect of these factors on the moduli of CNTs-CNT-reinforced composites. It is established that the waviness and agglomeration may significantly reduce the stiffening effect of CNTs, while the interface between the matrix and CNTs influence the moduli of CNTs-reinforced composites little.In this paper, the frictional sliding of microcracks under complex triaxial loading is analyzed, and the obtained results are incorporated into the constitutive relation of microcrack-weakened brittle materials.

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