scholarly journals Poly(furfuryl alcohol)-Polycaprolactone Blends

Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1069 ◽  
Author(s):  
Gabriele Nanni ◽  
José A. Heredia-Guerrero ◽  
Uttam C. Paul ◽  
Silvia Dante ◽  
Gianvito Caputo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Furfuryl Alcohol ◽  
Barrier Properties ◽  
Tensile Tests ◽  
Attenuated Total Reflection ◽  
Toxicity Tests ◽  
Scanning Calorimetry ◽  
Blend Films ◽  
Force Microscopy ◽  
Atomic Force

Poly(furfuryl alcohol) (PFA) is a bioresin synthesized from furfuryl alcohol (FA) that is derived from renewable saccharide-rich biomass. In this study, we compounded this bioresin with polycaprolactone (PCL) for the first time, introducing new functional polymer blends. Although PCL is biodegradable, its production relies on petroleum precursors such as cyclohexanone oils. With the method proposed herein, this dependence on petroleum-derived precursors/monomers is reduced by using PFA without significantly modifying some important properties of the PCL. Polymer blend films were produced by simple solvent casting. The blends were characterized in terms of surface topography by atomic force microscopy (AFM), chemical interactions between PCL and PFA by attenuated total reflection-Fourier transform infrared (ATR-FTIR), crystallinity by XRD, thermal properties by differential scanning calorimetry (DSC), and mechanical properties by tensile tests and biocompatibility by direct and indirect toxicity tests. PFA was found to improve the gas barrier properties of PCL without compromising its mechanical properties, and it demonstrated sustained antioxidant effect with excellent biocompatibility. Our results indicate that these new blends can be potentially used in diverse applications ranging from food packing to biomedical devices.

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 New thermoplastic poly(carbonate-urethane) elastomers

2011 ◽  
Vol 13 (1) ◽  
pp. 23-30 ◽  
Author(s):  
Anna Kultys ◽  
Magdalena Rogulska
Keyword(s):  
Soft Segment ◽  
Tensile Tests ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Force Microscopy ◽  
Melt Polymerization ◽  
Atomic Force ◽  
Amorphous Structures ◽  
A Chain ◽  
Poly Carbonate

New thermoplastic poly(carbonate-urethane) elastomersTwo series of novel thermoplastic poly(carbonate-urethane) elastomers, with different hard-segment content (30 - 60 wt %), were synthesized by melt polymerization from poly(hexane-1,6-diyl carbonate) diol of Mn= 2000 as a soft segment, 4,4'-diphenylmethane diisocyanate (MDI) or hexane-1,6-diyl diisocyanate (HDI) and 6,6'-[methylenebis(1,4-phenylenemethylenethio)]dihexan-1-ol as a chain extender. The structure and basic properties of the polymers were examined by Fourier transform infrared spectroscopy, X-ray diffraction analysis, atomic force microscopy, differential scanning calorimetry, thermogravimetric analysis, Shore hardness and tensile tests. The resulting TPUs were colorless polymers, showing almost amorphous structures. The MDI-based TPUs showed higher tensile strengths (up to 21.3 MPa vs. 15.8 MPa) and elongations at break (up to 550% vs. 425%), but poorer low-temperature properties than the HDI-based analogs.

scholarly journals Morphological and Mechanical Properties of Electrospun Polycaprolactone Scaffolds: Effect of Applied Voltage

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 662
Author(s):  
L.A. Can-Herrera ◽  
A.I. Oliva ◽  
M.A.A. Dzul-Cervantes ◽  
O.F. Pacheco-Salazar ◽  
J.M. Cervantes-Uc
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Surface Area ◽  
Applied Voltage ◽  
Pore Volume ◽  
Morphological Changes ◽  
Tensile Tests ◽  
Clear Correlation ◽  
Force Microscopy ◽  
Atomic Force

The aim of this work is to investigate the effect of the applied voltage on the morphological and mechanical properties of electrospun polycaprolactone (PCL) scaffolds for potential use in tissue engineering. The morphology of the scaffolds was characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), and the BET techniques for measuring the surface area and pore volume. Stress-strain curves from tensile tests were obtained for estimating the mechanical properties. Additional studies for detecting changes in the chemical structure of the electrospun PCL scaffolds by Fourier transform infrared were performed, while contact angle and X-ray diffraction analysis were realized for determining the wettability and crystallinity, respectively. The SEM, AFM and BET results demonstrate that the electrospun PCL fibers exhibit morphological changes with the applied voltage. By increasing the applied voltage (10 to 25 kV) a significate influence was observed on the fiber diameter, surface roughness, and pore volume. In addition, tensile strength, elongation, and elastic modulus increase with the applied voltage, the crystalline structure of the fibers remains constant, and the surface area and wetting of the scaffolds diminish. The morphological and mechanical properties show a clear correlation with the applied voltage and can be of great relevance for tissue engineering.

scholarly journals Characteristics of polyurethane-based sustained release membranes for drug delivery

2013 ◽  
Vol 11 (4) ◽  
pp. 542-553 ◽  
Author(s):  
Mihaela Mândru ◽  
Constantin Ciobanu ◽  
Stelian Vlad ◽  
Maria Butnaru ◽  
Laurent Lebrun ◽  
...  
Keyword(s):  
Surface Morphology ◽  
Physicochemical Characterization ◽  
Dermal Fibroblasts ◽  
Attenuated Total Reflection ◽  
Inversion Method ◽  
Scanning Calorimetry ◽  
Force Microscopy ◽  
Atomic Force ◽  
Polyurethane Membranes ◽  
Phase Inversion Method

AbstractThis paper is focused on the preparation and physicochemical characterization of two poly(ester ether urethane)s with rifampicin in their matrix and different molar concentrations of urethane groups. The polyurethanes with rifampicin were processed as asymmetrical microporous membranes by a phase inversion method and characterized by attenuated total reflection — Fourier transform infrared (ATR-FTIR) spectroscopy and differential scanning calorimetry (DSC). The influence of the surface morphology in the release of drug compounds was analyzed by scanning electron microscopy (SEM), atomic force microscopy (AFM), contact angle, and water uptake. The release of rifampicin depends on the molar concentration of urethane groups and also on the surface morphology of the polyurethane membranes. The antibacterial activity was evaluated with S. Epidermidis RP 62 A and P. Aeruginosa ATCC 1544. Finally, the biocompatibility of the polyurethane membranes was studied with human dermal fibroblasts (HDF) to evaluate the potential biomedical applications.

scholarly journals High-stress study of bioinspired multifunctional PEDOT:PSS/nanoclay nanocomposites using AFM, SEM and numerical simulation

2017 ◽  
Vol 8 ◽  
pp. 2069-2082 ◽  
Author(s):  
Alfredo J Diaz ◽  
Hanaul Noh ◽  
Tobias Meier ◽  
Santiago D Solares
Keyword(s):  
Mechanical Properties ◽  
High Stress ◽  
Barrier Properties ◽  
Conductive Atomic Force Microscopy ◽  
Force Microscopy ◽  
Probe Diameter ◽  
Atomic Force ◽  
Stress Study ◽  
Brick And Mortar ◽  
Induced Changes

Bioinspired design has been central in the development of hierarchical nanocomposites. Particularly, the nacre-mimetic brick-and-mortar structure has shown excellent mechanical properties, as well as gas-barrier properties and optical transparency. Along with these intrinsic properties, the layered structure has also been utilized in sensing devices. Here we extend the multifunctionality of nacre-mimetics by designing an optically transparent and electron conductive coating based on PEDOT:PSS and nanoclays Laponite RD and Cloisite Na+. We carry out extensive characterization of the nanocomposite using transmittance spectra (transparency), conductive atomic force microscopy (conductivity), contact-resonance force microscopy (mechanical properties), and SEM combined with a variety of stress-strain AFM experiments and AFM numerical simulations (internal structure). We further study the nanoclay’s response to the application of pressure with multifrequency AFM and conductive AFM, whereby increases and decreases in conductivity can occur for the Laponite RD composites. We offer a possible mechanism to explain the changes in conductivity by modeling the coating as a 1-dimensional multibarrier potential for electron transport, and show that conductivity can change when the separation between the barriers changes under the application of pressure, and that the direction of the change depends on the energy of the electrons. We did not observe changes in conductivity under the application of pressure with AFM for the Cloisite Na+ nanocomposite, which has a large platelet size compared with the AFM probe diameter. No pressure-induced changes in conductivity were observed in the clay-free polymer either.

Properties of poly(γ-benzyl l-glutamate) membrane modified by polyurethane containing carboxyl group

2011 ◽  
Vol 65 (4) ◽  
Author(s):  
Guo-Quan Zhu ◽  
Fa-Gang Wang ◽  
Qiao-Chun Gao ◽  
Guo-Chang Li ◽  
Ping Wang
Keyword(s):  
Chemical Properties ◽  
Tensile Tests ◽  
Carboxyl Group ◽  
Scanning Calorimetry ◽  
Physical Methods ◽  
Force Microscopy ◽  
Atomic Force ◽  
Blend Membranes ◽  
Scanning Electron ◽  
And Chemical Properties

AbstractA series of poly(γ-benzyl l-glutamate) (PBLG)/polyurethane (PU) containing carboxyl group blend membranes was prepared by casting the polymer blend solution in dimethylformamide (DMF). The surface morphology of the PBLG/PU blend membranes was investigated by atomic force microscopy (AFM) and scanning electron microscopy (SEM). Thermal, mechanical, and chemical properties of PBLG/PU blend membranes were studied by differential scanning calorimetry (DSC), tensile tests and other physical methods. It was revealed that the introduction of PU could exert outstanding effects on the morphology and the properties of PBLG membrane.

scholarly journals Pre-grafted Group on PE Surface by DBD Plasma and Its Influence on the Oxygen Permeation with Coated SiOx

Molecules ◽  
2019 ◽  
Vol 24 (4) ◽  
pp. 780 ◽  
Author(s):  
Hua Li ◽  
Lizhen Yang ◽  
Zhengduo Wang ◽  
Zhongwei Liu ◽  
Qiang Chen
Keyword(s):  
Transmission Rate ◽  
Barrier Properties ◽  
Attenuated Total Reflection ◽  
Great Decrease ◽  
Dbd Plasma ◽  
Polymeric Surfaces ◽  
Force Microscopy ◽  
Oxygen Transmission Rate ◽  
Atomic Force ◽  
Fold Reduction

In this paper, we report on polyethylene (PE) film modified by atmospheric dielectric barrier discharge (DBD) plasma prior to the deposition of SiOx coating to improve its barrier properties. Three kinds of monomers: allylamine, acrylic acid, and ethanol, are used to modify the PE surface. For comparison, Ar and O2 plasma pre-treatments are also performed. It is found that with the addition of a monomer in the Ar DBD plasma, the grafted active groups on PE surfaces lead to dense, pinhole-free growth of the SiOx film. The oxygen transmission rate (OTR) decreases from 700 cc/m2·day·atm. for the pristine to ca. 70 cc/m2·day·atm. for the pretreatment-coated PE, which is more than a 10-fold reduction. The relationship between the grafted monomer and the great decrease of OTR is then explored via chemical composition by attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and via morphology observation by atomic force microscopy (AFM) and scanning electron microscopy (SEM). The results show that the grafted functional groups of -NH2, -COOH and -OH increase the surface energy and promote the nucleation of Si–O radicals on polymeric surfaces, and the formation of network and cage structures in SiOx film contributes to the significant improvement of OTR.

scholarly journals One-Pot Process: Microwave-Assisted Keratin Extraction and Direct Electrospinning to Obtain Keratin-Based Bioplastic

2021 ◽  
Vol 22 (17) ◽  
pp. 9597
Author(s):  
Elena Pulidori ◽  
Simone Micalizzi ◽  
Emilia Bramanti ◽  
Luca Bernazzani ◽  
Celia Duce ◽  
...  
Keyword(s):  
Barrier Properties ◽  
Tensile Tests ◽  
Extraction Yield ◽  
Attenuated Total Reflection ◽  
Conventional Heating ◽  
Uniaxial Tensile ◽  
Scanning Calorimetry ◽  
One Pot ◽  
Microwave Assisted ◽  
Poultry Feathers

Poultry feathers are among the most abundant and polluting keratin-rich waste biomasses. In this work, we developed a one-pot microwave-assisted process for eco-friendly keratin extraction from poultry feathers followed by a direct electrospinning (ES) of the raw extract, without further purification, to obtain keratin-based bioplastics. This microwave-assisted keratin extraction (MAE) was conducted in acetic acid 70% v/v. The effects of extraction time, solvent/feathers ratio, and heating mode (MAE vs conventional heating) on the extraction yield were investigated. The highest keratin yield (26 ± 1% w/w with respect to initial feathers) was obtained after 5 h of MAE. Waste-derived keratin were blended with gelatin to fabricate keratin-based biodegradable and biocompatible bioplastics via ES, using 3-(Glycidyloxypropyl)trimethoxysilane (GPTMS) as a cross-linking agent. A full characterization of their thermal, mechanical, and barrier properties was performed by differential scanning calorimetry, thermogravimetric analysis, uniaxial tensile tests, and water permeability measurements. Their morphology and protein structure were investigated using scanning electron microscopy and attenuated total reflection-infrared spectroscopy. All these characterizations highlighted that the properties of the keratin-based bioplastics can be modulated by changing keratin and GPTMS concentrations. These bioplastics could be applied in areas such as bio-packaging and filtration/purification membranes.

scholarly journals Investigation on the Microscopic/Macroscopic Mechanical Properties of a Thermally Annealed Nafion® Membrane

Polymers ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 4018
Author(s):  
Tuyet Anh Pham ◽  
Seunghoe Koo ◽  
Hyunseok Park ◽  
Quang Thien Luong ◽  
Oh Joong Kwon ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fuel Cell ◽  
Annealing Temperature ◽  
Essential Element ◽  
Tensile Tests ◽  
Force Microscopy ◽  
Electrolyte Membrane ◽  
Atomic Force ◽  
Electrolyte Membranes ◽  
Temperature Ranges

The Nafion® electrolyte membrane, which provides a proton pathway, is an essential element in fuel cell systems. Thermal treatment without additional additives is widely used to modify the mechanical properties of the membrane, to construct reliable and durable electrolyte membranes in the fuel cell. We measured the microscopic mechanical properties of thermally annealed membranes using atomic force microscopy with the two-point method. Furthermore, the macroscopic property was investigated through tensile tests. The microscopic modulus exceeded the macroscopic modulus over all annealing temperature ranges. Additionally, the measured microscopic modulus increased rapidly near 150 °C and was saturated over that temperature, whereas the macroscopic modulus continuously increased until 250 °C. This mismatched micro/macroscopic reinforcement trend indicates that the internal reinforcement of the clusters is induced first until 150 °C. In contrast, the reinforcement among the clusters, which requires more thermal energy, probably progresses even at a temperature of 250 °C. The results showed that the annealing process is effective for the surface smoothing and leveling of the Nafion® membrane until 200 °C.

Epoxidized polybutadiene rubber as an effective compatibilizer for acrylonitrile butadiene rubber and polybutadiene rubber blend

2021 ◽  
pp. 009524432110171
Author(s):  
Vivek K Srivastava ◽  
Ganesh C Basak ◽  
Sukdeb Saha ◽  
GS Srinivasa Rao ◽  
Raksh Vir Jasra
Keyword(s):  
Mechanical Properties ◽  
Tensile Modulus ◽  
Butadiene Rubber ◽  
Scanning Calorimetry ◽  
Elongation At Break ◽  
Force Microscopy ◽  
Acrylonitrile Butadiene Rubber ◽  
Atomic Force ◽  
Polybutadiene Rubber ◽  
Compatibilized Blends

In the present study, epoxidized polybutadiene rubber (EBR; 30 mol% epoxidation) was synthesized using commercial-grade cis-polybutadiene rubber (BR). The EBR was successfully utilized as an effective compatibilizer between two incompatible elastomers, namely polar acrylonitrile butadiene rubber (NBR) and non-polar polybutadiene rubber (BR). The NBR and BR were blended in varied formulations and studied for morphological and mechanical properties. The observed properties of the blends containing EBR, as a compatibilizer, were compared with analogous blends without EBR. The optimum loading of EBR in NBR/BR formulations was found to be 5 phr (parts per hundred gram of rubber). The significant improvement in various mechanical properties such as tensile strength, tensile modulus, elongation at break and hardness were observed in presence of optimum loading of EBR in NBR/BR blends. Atomic Force Microscopy (AFM), Differential Scanning Calorimetry (DSC) and Dynamic Mechanical Analyser (DMA) studies revealed that the compatibility between two incompatible rubbers improved in the presence of EBR. The results observed with EBR-compatibilized blends revealed that EBR can be used as an effective compatibilizer between two incompatible rubbers (NBR and BR).

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