scholarly journals Carrier Fibers for the Safe Dosage of Nanoparticles in Nanocomposites: Nanomechanical and Thermomechanical Study on Polycarbonate/Boehmite Electrospun Fibers Embedded in Epoxy Resin

2021 ◽  
Author(s):  
Natalia Cano Murillo ◽  
Media Ghasem Zadeh Khorasani ◽  
Dorothee Silbernagl ◽  
Farnaz Emamverdi ◽  
Karen Cacua ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Epoxy Resin ◽  
Fiber Composite ◽  
Ambient Air ◽  
Mechanical Analysis ◽  
Thermomechanical Properties ◽  
Force Microscopy ◽  
Atomic Force ◽  
Fiber Reinforced Polymer Composites ◽  
Boehmite Nanoparticles

The reinforcing effect of boehmite nanoparticles (BNP) in epoxy resins for fiber composite lightweight construction is related to the formation of a soft but bound interphase between filler and polymer. The interphase is able to dissipate crack propagation energy and consequently increases the fracture toughness of the epoxy resin. Usually, the nanoparticles are dispersed in the resin and then mixed with the hardener to form an applicable mixture to impregnate the fibers. If one wishes to locally increase the fracture toughness at particularly stressed positions of the fiber-reinforced polymer composites (FRPC), this could be done by spraying nanoparticles from a suspension. However, this would entail high costs for removing the nanoparticles from the ambient air. We propose that a fiber fleece containing bound nanoparticles be inserted at exposed locations. For the present proof-of-concept study, an electrospun polycarbonate nonwoven and taurine modified BNP are proposed. After fabrication of suitable PC/EP/BNP composites, the thermomechanical properties were tested by dynamic mechanical analysis (DMTA). Comparatively, the local nano-mechanical properties such as stiffness and elastic modulus were determined by atomic force microscopy (AFM). An additional investigation of the distribution of the nanoparticles in the epoxy matrix, which is a prerequisite for an effective nanocomposite, is carried out by scanning electron microscopy in transmission mode (TSEM). From the results it can be concluded that the concept of carrier fibers for nanoparticles is viable.

scholarly journals Carrier Fibers for the Safe Dosage of Nanoparticles in Nanocomposites: Nanomechanical and Thermomechanical Study on Polycarbonate/Boehmite Electrospun Fibers Embedded in Epoxy Resin

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1591
Author(s):  
Natalia Cano Murillo ◽  
Media Ghasem Zadeh Khorasani ◽  
Dorothee Silbernagl ◽  
Farnaz Emamverdi ◽  
Karen Cacua ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Epoxy Resin ◽  
Fiber Composite ◽  
Ambient Air ◽  
Mechanical Analysis ◽  
Thermomechanical Properties ◽  
Force Microscopy ◽  
Atomic Force ◽  
Fiber Reinforced Polymer Composites ◽  
Boehmite Nanoparticles

The reinforcing effect of boehmite nanoparticles (BNP) in epoxy resins for fiber composite lightweight construction is related to the formation of a soft but bound interphase between filler and polymer. The interphase is able to dissipate crack propagation energy and consequently increases the fracture toughness of the epoxy resin. Usually, the nanoparticles are dispersed in the resin and then mixed with the hardener to form an applicable mixture to impregnate the fibers. If one wishes to locally increase the fracture toughness at particularly stressed positions of the fiber-reinforced polymer composites (FRPC), this could be done by spraying nanoparticles from a suspension. However, this would entail high costs for removing the nanoparticles from the ambient air. We propose that a fiber fleece containing bound nanoparticles be inserted at exposed locations. For the present proof-of-concept study, an electrospun polycarbonate nonwoven and taurine modified BNP are proposed. After fabrication of suitable PC/EP/BNP composites, the thermomechanical properties were tested by dynamic mechanical analysis (DMA). Comparatively, the local nanomechanical properties such as stiffness and elastic modulus were determined by atomic force microscopy (AFM). An additional investigation of the distribution of the nanoparticles in the epoxy matrix, which is a prerequisite for an effective nanocomposite, is carried out by scanning electron microscopy in transmission mode (TSEM). From the results it can be concluded that the concept of carrier fibers for nanoparticles is viable.

scholarly journals Preparation, Thermal, and Thermo-Mechanical Characterization of Polymeric Blends Based on Di(meth)acrylate Monomers

Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 878
Author(s):  
Krystyna Wnuczek ◽  
Andrzej Puszka ◽  
Łukasz Klapiszewski ◽  
Beata Podkościelna
Keyword(s):  
Mechanical Analysis ◽  
Attenuated Total Reflection ◽  
Scanning Calorimetry ◽  
Force Microscopy ◽  
Chemical Structures ◽  
Atomic Force ◽  
Polymeric Blends ◽  
Ft Ir ◽  
Acrylate Monomers ◽  
Synthesized Materials

This study presents the preparation and the thermo-mechanical characteristics of polymeric blends based on di(meth)acrylates monomers. Bisphenol A glycerolate diacrylate (BPA.GDA) or ethylene glycol dimethacrylate (EGDMA) were used as crosslinking monomers. Methyl methacrylate (MMA) was used as an active solvent in both copolymerization approaches. Commercial polycarbonate (PC) was used as a modifying soluble additive. The preparation of blends and method of polymerization by using UV initiator (Irqacure® 651) was proposed. Two parallel sets of MMA-based materials were obtained. The first included more harmless linear hydrocarbons (EGDMA + MMA), whereas the second included the usually used aromatic copolymers (BPA.GDA + MMA). The influence of different amounts of PC on the physicochemical properties was discussed in detail. Chemical structures of the copolymers were confirmed by attenuated total reflection–Fourier transform infrared (ATR/FT-IR) spectroscopy. Thermo-mechanical properties of the synthesized materials were investigated by means of differential scanning calorimetry (DSC), thermogravimetric (TG/DTG) analyses, and dynamic mechanical analysis (DMA). The hardness of the obtained materials was also tested. In order to evaluate the surface of the materials, their images were obtained with the use of atomic force microscopy (AFM).

scholarly journals Layered calcium phenylphosphonate: a hybrid material for a new generation of nanofillers

2018 ◽  
Vol 9 ◽  
pp. 2906-2915 ◽  
Author(s):  
Kateřina Kopecká ◽  
Ludvík Beneš ◽  
Klára Melánová ◽  
Vítězslav Zima ◽  
Petr Knotek ◽  
...  
Keyword(s):  
Mechanical Analysis ◽  
Gas Permeation ◽  
Synthesis Methods ◽  
X Ray Diffraction ◽  
Promising Technique ◽  
Force Microscopy ◽  
Atomic Force ◽  
Strong Shear ◽  
New Generation ◽  
Composite Properties

The use of nanosheets of layered calcium phenylphosphonate as a filler in a polymeric matrix was investigated. Layered calcium phenylphosphonate (CaPhP), with chemical formula CaC6H5PO3∙2H2O, is a hybrid organic–inorganic material that exhibits a hydrophobic character due to the presence of phenyl groups on the surface of the layers. In this paper, various CaPhP synthesis methods were studied with the aim of obtaining a product most suitable for its subsequent exfoliation. The liquid-based approach was used for the exfoliation. It was found that the most promising technique for the exfoliation of CaPhP in an amount sufficient for incorporation into polymers involved using propan-2-ol with a strong shear force generated in a high-shear disperser. The filler was tested both in its unexfoliated and exfoliated forms for the preparation of polymer composites, for which a low molecular weight epoxy resin based on bisphenol A was used as a polymer matrix. The prepared samples were characterized by powder X-ray diffraction, atomic force microscopy, optical and scanning electron microscopy, and dynamic mechanical analysis. Flammability and gas permeation tests were also performed. The addition of the nanofiller was found to influence the composite properties – the exfoliated particles were found to have a higher impact on the properties of the prepared composites than the unexfoliated particles of the same loading

scholarly journals Study on the morphology and thermomechanical properties of poly(urethane-siloxane) networks based on hyperbranched polyester

2013 ◽  
Vol 67 (6) ◽  
pp. 871-879
Author(s):  
Marija Pergal ◽  
Jasna Dzunuzovic ◽  
Milena Spírková ◽  
Rafal Poręba ◽  
Milos Steinhart ◽  
...  
Keyword(s):  
Ethylene Oxide ◽  
Microphase Separation ◽  
Soft Segment ◽  
Hydrophobic Surface ◽  
Crosslinking Density ◽  
Thermomechanical Properties ◽  
Hyperbranched Polyester ◽  
Force Microscopy ◽  
X Ray Scattering ◽  
Atomic Force

Two series of polyurethane films based on hyperbranched polyester of the second pseudogeneration (Boltorn?), 4,4'-methylenediphenyl diisocyanate and two different siloxane prepolymers, ?,?-dihydroxy-(ethylene oxide-poly(dimethylsiloxane)-ethylene oxide) (EO-PDMS-EO) and ?,?-dihydroxypropyl-poly(dimethylsiloxane) (HP-PDMS), were prepared by two-step polymerization in solution. The influence of the type and content of soft segment on the morphology, thermomechanical and surface properties of the synthesized polyurethanes was studied by atomic force microscopy (AFM), small-angle X-ray scattering (SAXS), scanning electron microscopy (SEM), dynamic mechanical thermal analysis (DMTA) and water absorption measurements. It was found that these techniques confirmed existence of microphase separated morphology. Synthesized polyurethanes exhibited two glass transition temperatures and one second relaxation process. The results showed that polyurethanes based on HP-PDMS had higher surface roughness, better microphase separation and waterproof performances. Samples synthesized with lower PDMS content had less hydrophobic surface, but higher crosslinking density and better thermomechanical properties. (Projekat Ministarstva nauke Republike Srbije, br. 172062]

scholarly journals Coupling the Microscopic Healing Behaviour of Coatings to the Thermoreversible Diels-Alder Network Formation

Coatings ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 13 ◽  
Author(s):  
Joost Brancart ◽  
Robrecht Verhelle ◽  
Jessica Mangialetto ◽  
Guy Van Assche
Keyword(s):  
Network Formation ◽  
Polymer Network ◽  
Cycloaddition Reaction ◽  
Thermomechanical Properties ◽  
Alder Reaction ◽  
Diels Alder ◽  
Force Microscopy ◽  
Diels Alder Reaction ◽  
Atomic Force ◽  
Microscopic Evaluation

While thermally reversible polymer network coatings based on the Diels-Alder reaction are widely studied, the mechanisms responsible for the heating-mediated healing of damage is still not well understood. The combination of microscopic evaluation techniques and fundamental insights for the thermoreversible network formation in the bulk and coating shed light on the mechanisms behind the damage healing events. The thermomechanical properties of thermoset and elastomer coatings, crosslinked by the furan-maleimide Diels-Alder cycloaddition reaction, were studied in bulk and compared to the thermal behaviour applied as coatings onto aluminium substrates. The damage sealing of thermoset (Tg = 79 °C) and elastomer (Tg = −49 °C) coatings were studied using nano-lithography and atomic force microscopy (AFM). The sealing event is studied and modelled at multiple temperatures and correlated to the changes in the network structure and corresponding thermomechanical properties.

Quantitative mechanical analysis of indentations on layered, soft elastic materials

Soft Matter ◽  
2019 ◽  
Vol 15 (8) ◽  
pp. 1776-1784 ◽  
Author(s):  
Bryant L. Doss ◽  
Kiarash Rahmani Eliato ◽  
Keng-hui Lin ◽  
Robert Ros
Keyword(s):  
Atomic Force Microscopy ◽  
Elastic Modulus ◽  
Cell Mechanics ◽  
Biological Samples ◽  
Mechanical Analysis ◽  
Elastic Materials ◽  
Mechanical Heterogeneity ◽  
Popular Method ◽  
Force Microscopy ◽  
Atomic Force

Atomic force microscopy (AFM) is becoming an increasingly popular method for studying cell mechanics, however the existing analysis tools for determining the elastic modulus from indentation experiments are unable to quantitatively account for mechanical heterogeneity commonly found in biological samples.

Using Demercurated Lighting Phosphor and MSWI Scrubber Residues to Prepare High Performance Plastic Concrete

2009 ◽  
Vol 610-613 ◽  
pp. 55-60
Author(s):  
Wu Jang Huang ◽  
Wei Chu ◽  
Ling Hui Hsieh ◽  
Jian Guo Chen
Keyword(s):  
Thermal Properties ◽  
Epoxy Resin ◽  
Solid Waste ◽  
High Performance ◽  
Waste Incineration ◽  
Type I ◽  
Phosphor Powder ◽  
Force Microscopy ◽  
Atomic Force ◽  
Plastic Concrete

This study aimed to prepare a high performance plastic concrete made of epoxy resin and Portland type-I cement mixed with at least one inorganic solid waste of demercurated lighting phosphor powder or municipal solid waste incineration scrubber residue. The ratio between liquid epoxy resin and cement was 1:2; the scrubber residue and demercurated phosphor powder were added as modifiers for cement component in order to improve the strength and thermal properties of synthesized plastic concrete. The results indicate that, the addition of scrubber residue causes a decrease in both strength and thermal properties; whereas, the demercurated phosphor powder can replace 100% of the contents of cement without any significantly change in either strength or thermal properties. Atomic force microscopy and Raman spectroscopy were used to characterize the chemical structure of cured concrete and the results indicate that the surface softness increases with an increase in the mixed percentage of epoxy resin.

An Investigation of the Chemical Changes of Artists' Acrylic Paint Films When Exposed to Water

2004 ◽  
Vol 852 ◽  
Author(s):  
R. Ploeger ◽  
A. Murray ◽  
S. Hesp ◽  
D. Scalarone
Keyword(s):  
Paint Film ◽  
Capillary Rise ◽  
Mechanical Analysis ◽  
Conductivity Measurements ◽  
Chemical Changes ◽  
Force Microscopy ◽  
Acrylic Paint ◽  
Atomic Force ◽  
Colour Measurements ◽  
Paint Films

ABSTRACTThis paper addresses some of the conservation concerns of artists' acrylic paints by investigating the chemical changes of the paint films caused during a one-hour exposure to water experiments and the rate at which some of the changes occur. Three different acrylic paint films were investigated. Real-time capillary rise, conductivity measurements and thermo-mechanical analysis (TMA) gave an indication of the rate at which these changes occurred. Much of the measurable leaching occurred within the first 20 minutes of the paint film being exposed to water, while the most rapid leaching occurred within the first five minutes, before approaching an equilibrium state. All physical and visual changes in colour, gloss, dimension, mass and surface morphology (using atomic force microscopy, AFM) were monitored. A decrease in size and mass indicated that material had been permanently removed from the paint films. Gloss and colour measurements, as well as AFM images, also showed evidence of changes caused by the exposure to water.

scholarly journals Effect of Modification with Various Epoxide Compounds on Mechanical, Thermal, and Coating Properties of Epoxy Resin

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Alaaddin Cerit ◽  
Mustafa Esen Marti ◽  
Ulku Soydal ◽  
Suheyla Kocaman ◽  
Gulnare Ahmetli
Keyword(s):  
Thermal Stability ◽  
Atomic Force Microscopy ◽  
Tensile Strength ◽  
Epoxy Resin ◽  
Curing Process ◽  
Coating Properties ◽  
Corrosive Media ◽  
Force Microscopy ◽  
Atomic Force ◽  
Thermal Stability Of

Epoxy resin (ER) was modified with four different epoxide compounds, 4,5-epoxy-4-methyl-pentane-2-on (EMP), 3-phenyl-1,2-epoxypropane (PhEP), 1-chloro-2,3-epoxy-5-(chloromethyl)-5-hexene (CEH), and a fatty acid glycidyl ester (FAGE), to improve its chemical and physical properties. The effects of the addition and amount of these modifiers on mechanical, thermal, and coating properties were investigated. Atomic force microscopy was used to observe the changes obtained with the modification. The influence of the modifying agents on the curing process was monitored through FTIR spectroscopy. The curing degrees of ER and modified ERs (M-ERs) were found to be over 91%. The results showed that tensile strength of ER improved till 30% (wt.) with addition of the modifier content. Modification with EMP and PhEP remarkably enhanced the thermal stability of ER to be highly resistant to the corrosive media.

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