Structure, Wettability and Thermal Degradation of New Fluoro-Oligomer Modified Nanoclays

2008 ◽  
Vol 8 (4) ◽  
pp. 1835-1841 ◽  
Author(s):  
R. Valsecchi ◽  
M. Viganò ◽  
M. Levi ◽  
S. Turri
Keyword(s):  
Molecular Weight ◽  
Exchange Process ◽  
X Rays ◽  
Electronic Microscopy ◽  
Scanning Calorimetry ◽  
Degradation Temperature ◽  
Angle Measurements ◽  
Peculiar Behaviour ◽  
Contact Angle Measurements ◽  
Hysteresis Phenomena

Quaternary ammonium salts based on monofunctionalized Perfluoropolyether (PFPE) oligomers were synthesized and used for the cation exchange process of sodium Montmorillonite nanoclays. The new fluoromodified nanoclays were characterized through X-rays diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), termogravimetric analysis (TGA), differential scanning calorimetry (DSC), electronic microscopy (SEM-EDS), and contact angle measurements (CA). In particular XRD showed rather complex patterns (presence of higher order reflections) which allowed the calculation of basal spacings, regularly increasing with the molecular weight of the fluorinated macrocation. Both IR and SEM confirmed the presence of fluorinated segments at clays interface, while TGA showed a limited thermal stability with an onset of degradation temperature which seems not dependent on the molecular weight of the macrocation. CA measurements showed a peculiar behaviour, with evident dynamic hysteresis phenomena and surface tension components quite different from those of commercially available, organomodified clays.

scholarly journals Novel green biodegradable polylactide based polyurethane triblock copolymers reinforced with cellulose nanowhiskers

2021 ◽  
Author(s):  
Noha Ali Abdel Hady
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Cell Attachment ◽  
Triblock Copolymers ◽  
Cellulose Nanowhiskers ◽  
Angle Measurements ◽  
Degradation Rates ◽  
Contact Angle Measurements ◽  
Enhance Cell Attachment ◽  
Final Composition

Novel green classes of biodegradable polylactide-based triblock polyurethane (TBPU) polymers were synthesized. Owing to their tailored mechanical properties, improved degradation rates, and the enhance cell attachment potential compared with polylactide-homopolymer, they tested for biomedical applications. Triblock copolymers (TB) of different lactide and polyethylene glycol composition were first fabricated by ring-opening polymerization using tin octoate as catalyst. Afterwich polycaprolactone diole (PCL-diole) is reacted with TB copolymers using 1,4-butane diisocyanate (BDI) as nontoxic chain extender to form the final TBPUs. Final composition, molecular weight, thermal properties, hydrophilicity and biodegradation of the obtained TB and TBPU were studied and characterized using 1H-NMR, GPC, FTIR, DSC, SEM and contact angle measurements. Results obtained from the high molecular weight members of TBPUs showed improved hydrophilicity and degradation rates along with tailored mechanical properties. Nanocomposites obtained by reinforcing TBPU3 with 7% (w/w) BCNW showed ~16% increase in tensile strength and 330% in % elongation compared with PL-homopolymer. Those polymers and their nanocomposites demonstrated promising potential to be used as bone cement, and in regenerative medicin.

Analysis of the Mechanical Properties of Solvent Cast Blends of PLA/PCL

2014 ◽  
Vol 679 ◽  
pp. 50-56 ◽  
Author(s):  
Yuan Yuan Chen ◽  
Luke M. Geever ◽  
Clement L. Higginbotham ◽  
Declan M. Devine
Keyword(s):  
Mechanical Properties ◽  
Contact Angle ◽  
Tensile Test ◽  
Ductile Material ◽  
Infrared Spectrometry ◽  
Significant Shift ◽  
Scanning Calorimetry ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Mass Fractions

Polylactic acid (PLA) is the most promising material in the biodegradable category. However, brittleness and poor thermal stability restrict its application. To overcome this limitation, PLA may be blended with other biodegradable materials to tailor its properties while maintain biodegradability. In this study a series of blends of PLA and poly (ε-caprolactone) (PCL) with various mass fractions were prepared by solution method and solvent casting. Films of each blend were formed when the solvent evaporated. Subsequently, tensile test samples were punched out of the film for testing and tensile testing, Fourier transform infrared spectrometry (FTIR), Differential scanning Calorimetry (DSC) and contact angle measurements were carried out. Since PCL is a ductile material, the two materials were blended together in an effort to improve the mechanical properties. However, on thermal analysis of the blends, two individual melting peaks were observed in the DSC thermograms. Furthermore, no significant shift in peaks was observed on the FTIR spectra, and clear droplets and boundaries between two components of the blend can be observed in morphology study, all indicated the immiscibility of PLA and PCL. Tensile test showed poor mechanical properties due to the poor adhesion of the two immiscible components of the blend, and the addition of PCL did not influence the wettability of the surface of the blends as there were no significant differences in contact angle measurements.

scholarly journals A Combined Strategy to Improve the Performance of Dental Alloys Using a New CoCrNbMoZr Alloy with Mn and Si Coated via an Anodic Oxidation Procedure

Metals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1017
Author(s):  
Florentina Gina Ionascu ◽  
Mariana Prodana ◽  
Florentina Golgovici ◽  
Ioana Demetrescu
Keyword(s):  
Anodic Oxidation ◽  
Artificial Saliva ◽  
Open Circuit ◽  
X Rays ◽  
Dental Alloys ◽  
Angle Measurements ◽  
Corrosion Studies ◽  
Contact Angle Measurements ◽  
Improved Performance ◽  
Combined Strategy

The aim of the paper is based on a combined approach to improve dental alloy performance using a new Ni-free Co–Cr composition with Mo, Nb and Zr and coated with an anodic oxidation film. The coated and uncoated samples were surface characterized by performing SEM (scanning electronic microscopy), XRD (X-rays diffraction) contact angle measurements and corrosion studies with open circuit potential, potentiodynamic polarization and EIS (impedance electrochemical spectroscopy) procedures. The SEM equipment with an EDX (Energy-dispersive X-ray spectroscopy) module indicated the sample morphology and the XRD investigations established the formation of the oxides. The electrochemical procedures were performed in Ericsson artificial saliva for coated samples in various conditions. Based on all the experiments, including the decrease in the hydrophobic character of the uncoated samples and the decrease in the hydrophilic values of the anodized alloys, the improved performance of the coated samples was established as a conclusion.

scholarly journals Ultrasound Assisted Synthesis of Polylimonene and Organomodified-clay Nanocomposites: A Structural, Morphological and Thermal Properties

2020 ◽  
Vol 15 (3) ◽  
pp. 798-807
Author(s):  
Hodhaifa Derdar ◽  
Geoffrey Robert Mitchell ◽  
Zakaria Cherifi ◽  
Mohammed Belbachir ◽  
Mohamed Benachour ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Preparation Method ◽  
Exchange Process ◽  
Clay Nanocomposites ◽  
X Ray Diffraction ◽  
Electronic Microscopy ◽  
X Ray ◽  
Degradation Temperature ◽  
Ultrasonic Assisted ◽  
Ft Ir

Polylimonene-clay nanocomposites (PLM-Mag 2, 3, 6 and 10% by weight of clay) were prepared by mixing Maghnite-CTA+ (Mag-CTA+) and polylimonene (PLM) in solution using ultrasonic irradiation. The catalyst preparation method were studied in order to determine and evaluate their structural, morphological and thermal properties. The Mag-CTA+ is an organophylic montmorillonite silicate clay prepared through a direct exchange process, using green natural clay of Maghnia (west of Algeria) called Maghnite. The Algerian clay was modified by ultrasonic-assisted method using cetyltrimethylammonuim bromide (CTAB) in which they used as green nano-reinforcing filler. Polylimonene was obtained by the polymerization of limonene, using Mag-H+ as a catalyst. The morphology of the obtained nanocomposites was studied by X-ray diffraction (XRD), scanning electronic microscopy (SEM), transmission electronic microscopy (TEM) and infrared spectroscopy (FT-IR). Thermogravimetric analysis (TGA) shows that the nanocomposites have a high degradation temperature (200−250 °C) compared with the pure polylimonene (140 °C). The analyses confirmed the chemical modification of montmorillonite layers and their uniformly dispersion in the polylimonene matrix. Exfoliated structures were obtained for low amounts of clay (2 and 3% by weight), while intercalated structures and immiscible regions were detected for high amounts of clay (6 and 10% by weight). Copyright © 2020 BCREC Group. All rights reserved 

scholarly journals Novel green biodegradable polylactide based polyurethane triblock copolymers reinforced with cellulose nanowhiskers

2021 ◽  
Author(s):  
Noha Ali Abdel Hady
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Cell Attachment ◽  
Triblock Copolymers ◽  
Cellulose Nanowhiskers ◽  
Angle Measurements ◽  
Degradation Rates ◽  
Contact Angle Measurements ◽  
Enhance Cell Attachment ◽  
Final Composition

Novel green classes of biodegradable polylactide-based triblock polyurethane (TBPU) polymers were synthesized. Owing to their tailored mechanical properties, improved degradation rates, and the enhance cell attachment potential compared with polylactide-homopolymer, they tested for biomedical applications. Triblock copolymers (TB) of different lactide and polyethylene glycol composition were first fabricated by ring-opening polymerization using tin octoate as catalyst. Afterwich polycaprolactone diole (PCL-diole) is reacted with TB copolymers using 1,4-butane diisocyanate (BDI) as nontoxic chain extender to form the final TBPUs. Final composition, molecular weight, thermal properties, hydrophilicity and biodegradation of the obtained TB and TBPU were studied and characterized using 1H-NMR, GPC, FTIR, DSC, SEM and contact angle measurements. Results obtained from the high molecular weight members of TBPUs showed improved hydrophilicity and degradation rates along with tailored mechanical properties. Nanocomposites obtained by reinforcing TBPU3 with 7% (w/w) BCNW showed ~16% increase in tensile strength and 330% in % elongation compared with PL-homopolymer. Those polymers and their nanocomposites demonstrated promising potential to be used as bone cement, and in regenerative medicin.

scholarly journals Influence of the Preparation Method and Photo-Oxidation Treatment on the Thermal and Gas Transport Properties of Dense Films Based on a Poly(ether-block-amide) Copolymer

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1326 ◽  
Author(s):  
Gabriele Clarizia ◽  
Paola Bernardo ◽  
Giuliana Gorrasi ◽  
Daniela Zampino ◽  
Sabrina Carroccio
Keyword(s):  
Uv Irradiation ◽  
Preparation Method ◽  
Irradiation Time ◽  
Scanning Calorimetry ◽  
Water Contact ◽  
Photo Oxidation ◽  
Flight Mass Spectrometry ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Dense Films

Dense films based on the hydrophobic Pebax®2533 were prepared by using solution casting in different solvents as well as compression molding and subjected to photo–aging under ultraviolet (UV) irradiation. The influence of the preparation method, including the casting solvents, as well as the UV irradiation time selected to treat the samples, were evaluated in terms of permeation rates of pure gases (CO2, N2, O2, CH4, He, and H2). The transport data were correlated with the microstructure and surface properties by using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS), as well as water contact angle measurements. The obtained results showed that a controlled photo-oxidation process reduces the hydrophobicity of the Pebax®2533 films, increasing their permeability without compromising their integrity.

scholarly journals Super-Efficient Synthesis of Mesh-like Superhydrophobic Nano-Aluminum/Iron (III) Oxide Energetic Films

Materials ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 234 ◽  
Author(s):  
Xiaogang Guo ◽  
Taotao Liang
Keyword(s):  
Contact Angle ◽  
Water Contact Angle ◽  
Energetic Materials ◽  
Scanning Calorimetry ◽  
Water Contact ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Aluminum Iron ◽  
Potential Applications ◽  
One Step

In this study, a novel superhydrophobic nano-aluminum/iron (III) oxide composite has been prepared by a facile one-step process of electrophoretic deposition, with wide potential applications. The optimal suspension included ethanol, acetyl-acetone, and the additives of fluorotriphenylsilane and perfluorodecyltriethoxysilane. The microstructure, wettability, and exothermic performance were analyzed by field emission scanning electron microcopy (FESEM), X-ray diffraction (XRD), water contact angle measurements, and the differential scanning calorimetry (DSC) technique. The water contact angle and the heat-release of the target composites could reach to ~170° and 2.67 kJ/g, and could still keep stable, after exposure for six months, showing a great stability. These results provided an exquisite synthesis of ideas, for designing other superhydrophobic energetic materials with self-cleaning properties, for real industrial application.

scholarly journals Bulk Modification of Poly(lactide) (PLA) via Copolymerization with Poly(propylene glycol) Diglycidylether (PPGDGE)

Polymers ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1184 ◽  
Author(s):  
Sandra Castillejos ◽  
Jorge Cerna ◽  
Francisco Meléndez ◽  
María Castro ◽  
Rocío Aguilar ◽  
...  
Keyword(s):  
Propylene Glycol ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Diglycidyl Ether ◽  
Scanning Calorimetry ◽  
Monomer Ratio ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Poly Propylene ◽  
Made In

Copolymers of l-lactide and poly(propylene glycol) diglycidyl ether (PPGDGE380) were synthesized by ring opening polymerization (ROP). Stannous octoate was used as the catalyst and 1-dodecanol as the initiator. The effect of the variables on the thermal properties of the copolymers was investigated by differential scanning calorimetry (DSC). Contact angle measurements were made in order to study the wettability of the synthesized copolymers. The copolymers differed widely in their physical characteristics, ranging from weak elastomers to tougher thermoplastics, according to the ratio of l-lactide and PPGDGE380. The results showed that the copolymers were more hydrophilic than neat Poly(lactide) (PLA) and the monomer ratio had a strong influence on the hydrophilic properties.

scholarly journals Green Nanocomposites from Rosin-Limonene Copolymer and Algerian Clay

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1971
Author(s):  
Hodhaifa Derdar ◽  
Geoffrey Robert Mitchell ◽  
Vidhura Subash Mahendra ◽  
Mohamed Benachour ◽  
Sara Haoue ◽  
...  
Keyword(s):  
Thermal Properties ◽  
In Situ Polymerization ◽  
Exchange Process ◽  
Lower Amount ◽  
Mechanical And Thermal Properties ◽  
Electronic Microscopy ◽  
Degradation Temperature ◽  
Ultrasonic Assisted ◽  
Organophilic Clay ◽  
Clay Layers

Green nanocomposites from rosin-limonene (Ros-Lim) copolymers based on Algerian organophilic-clay named Maghnite-CTA+ (Mag-CTA+) were prepared by in-situ polymerization using different amounts (1, 5 and 10% by weight) of Mag-CTA+ and azobisisobutyronitrile as a catalyst. The Mag-CTA+ is an organophilic montmorillonite silicate clay prepared through a direct exchange process; the clay was modified by ultrasonic-assisted method using cetyltrimethylammonuim bromide in which it used as green nano-filler.The preparation method of nanocomposites was studied in order to determine and improve structural, morphological, mechanical and thermal properties ofsin.The structure and morphology of the obtained nanocomposites(Ros-Lim/Mag-CTA+) were determined using Fourier transform infrared spectroscopy, X-ray diffraction, scanning electronic microscopy and transmission electronic microscopy. The analyses confirmed the chemical modification of clay layers and the intercalation of rosin-limonene copolymer within the organophilic-clay sheets. An exfoliated structure was obtained for the lower amount of clay (1% wt of Mag-CTA+), while intercalated structures were detected for high amounts of clay (5 and 10% wt of Mag-CTA+). The thermal properties of the nanocomposites were studied by thermogravimetric analysis (TGA) and show a significant improvement inthe thermal stability of the obtained nanocomposites compared to the purerosin-limonene copolymer (a degradation temperature up to 280 °C).

scholarly journals Preparation and Characterization of Chitosan/Poly(Vinyl Alcohol) Blended Films: Mechanical, Thermal and Surface Investigations

2011 ◽  
Vol 8 (1) ◽  
pp. 91-96 ◽  
Author(s):  
Esam A. El-Hefian ◽  
Mohamed Mahmoud Nasef ◽  
Abdul Hamid Yahaya
Keyword(s):  
Contact Angle ◽  
Poly Vinyl Alcohol ◽  
Scanning Calorimetry ◽  
Water Contact ◽  
Elongation At Break ◽  
Angle Measurements ◽  
Static Water Contact Angle ◽  
Contact Angle Measurements ◽  
Static Water

In this study, blends of chitosan (CS) and polyvinyl alcohol (PVA) (CS/PVA) having various proportions were prepared and characterized by universal mechanical tester, the differential scanning calorimetry (DSC) and contact angle measurements. Studying the mechanical properties of the films showed that blending improved the tensile strength, which increased with increasing PVA content up to 40% while the elongation% at break of the blends was decreased compared to that of the pure components. The obtained results of DSC suggested that some interaction between chitosan and PVA mostly took place. Static water contact angle measurements showed an improvement in the wettability of the obtained films.

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