Biocompatibility studies of polyurethane electrospun membranes based on arginine as chain extender

AbstractElectrospun polymers are an example of multi-functional biomaterials that improve the material-cellular interaction and aimed at enhancing wound healing. The main objective of this work is to fabricate electrospun polyurethane membranes using arginine as chain extender (PUUR) in order to test the fibroblasts affinity and adhesion on the material and the polymer toxicity. Polyurethane membranes were prepared in two steps: (i) the polyurethane synthesis, and ii) the electrospinning process. The membranes were characterized by scanning electron microscopy (SEM), Fourier transforms infrared spectroscopy, gel permeation chromatography, and differential scanning calorimetry techniques. The evaluation of PUUR as a scaffolding biomaterial for growing and developing of cells on the material was realized by LIVE/DEAD staining. The results show that the fluorescent surface area of human fibroblasts (hFB), was greater in control dense membranes made from Tecoflex than in electrospun and dense PUUR. From SEM analysis, the electrospun membranes show relatively uniform attachment of cells with a well-spread shape, while Tecoflex dense membranes show a non-proliferating round shape, which is attributed to the fiber’s structure in electrospun membranes. The cell morphology and the cell attachment assay results reveal the well spreading of hFB cells on the surface of electrospun PUUR membranes which indicates a good response related to cell adhesion.

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Nonwoven Bio-Based Membranes for Removal of Micropollutants from Aqueous Water

Materiale Plastice ◽

10.37358/mp.20.4.5404 ◽

2021 ◽

Vol 57 (4) ◽

pp. 34-44

Author(s):

Ecaterina Matei ◽

Cristina Ileana Covaliu ◽

George Coman ◽

Mihai Negroiu ◽

Maria Rapa ◽

...

Keyword(s):

Electrospinning Process ◽

Attenuated Total Reflectance ◽

Scanning Calorimetry ◽

Chemical Methods ◽

Physical Chemical ◽

Activated Coal ◽

Solid Suspension ◽

Electrospun Membranes ◽

Ft Ir

The aim of this paper is to obtain two types of bio-based membranes by electrospinning process: one based on polylactic acid (PLA), and PLA/polyhydroxybutyrate (PHB), and the second by coating the PLA/PHB membrane with chitosan (CS) and CS/activated coal (AC), respectively for removal of micropollutants from aqueous water. The designed bio-based electrospun membranes were analyzed through scanning electron microscopy (SEM), attenuated total reflectance (ATR) - Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), the removal of solid suspension and Pb (II) from aqueous water. The quality of filtrates was evaluated by physical-chemical methods, while the retaining of Pb (II) from wastewaters was reported.

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Processing and characterization of poly(lactic acid) blended with polycarbonate and chain extender

Journal of Polymer Engineering ◽

10.1515/polyeng-2013-0309 ◽

2014 ◽

Vol 34 (7) ◽

pp. 665-672 ◽

Cited By ~ 7

Author(s):

Yottha Srithep ◽

Wuttipong Rungseesantivanon ◽

Bongkot Hararak ◽

Krisda Suchiva

Keyword(s):

Molecular Weight ◽

Lactic Acid ◽

Gel Permeation Chromatography ◽

Chain Extender ◽

Chain Extension ◽

Morphological Properties ◽

Poly Lactic Acid ◽

Scanning Calorimetry ◽

Commercial Applications ◽

A Chain

Abstract Currently, use of poly(lactic acid) (PLA) is limited for commercial applications because it has a low heat resistance. In this research, an increase of over 40°C heat distortion temperature (HDT) of PLA alloy was obtained by blending PLA with polycarbonate (PC) and a chain extender (CE). Molecular weight, thermal, mechanical and morphological properties of PLA and PC blend with different CE contents were investigated. Gel permeation chromatography (GPC) results showed that some PLA-PC copolymers were produced and the compatibility of the PLA phase and in the PC phase was improved via the chain extension reaction. In addition, the reaction induced by CE also affected the crystallization behaviors of PLA, as observed from differential scanning calorimetry (DSC) results and the enthalpy of melting of PLA decreased with increasing CE content. The combined effects of the CE increasing molecular weight, improving compatibility and limiting the crystallization behavior of PLA/PC alloy greatly improved the HDT.

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Recycling Potential for Non-Valorized Plastic Fractions from Electrical and Electronic Waste

Recycling ◽

10.3390/recycling6020033 ◽

2021 ◽

Vol 6 (2) ◽

pp. 33

Author(s):

Laura Strobl ◽

Thomas Diefenhardt ◽

Martin Schlummer ◽

Tanja Leege ◽

Swetlana Wagner

Keyword(s):

Flame Retardants ◽

Electronic Waste ◽

Gel Permeation Chromatography ◽

Scanning Calorimetry ◽

Separation Processes ◽

Melt Flow Rate ◽

Density Fractions ◽

Material Recycling ◽

Other Substances ◽

Electrical And Electronic Waste

This paper describes a study for waste of electrical and electronic equipment (WEEE) to characterise the plastic composition of different mixed plastic fractions. Most of the samples studied are currently excluded from material recycling and arise as side streams in state-of-the-art plastics recycling plants. These samples contain brominated flame retardants (BFR) or other substances of concern listed as persistent organic pollutants or in the RoHS directive. Seventeen samples, including cathode ray tube (CRT) monitors, CRT televisions, flat screens such as liquid crystal displays, small domestic appliances, and information and communication technology, were investigated using density- and dissolution-based separation processes. The total bromine and chlorine contents of the samples were determined by X-ray fluorescence spectroscopy, indicating a substantial concentration of both elements in density fractions above 1.1 g/cm3, most significantly in specific solubility classes referring to ABS and PS. This was further supported by specific flame retardant analysis. It was shown that BFR levels of both polymers can be reduced to levels below 1000 ppm by dissolution and precipitation processes enabling material recycling in compliance with current legislation. As additional target polymers PC and PC-ABS were also recycled by dissolution but did not require an elimination of BFR. Finally, physicochemical investigations of recycled materials as gel permeation chromatography, melt flow rate, and differential scanning calorimetry suggest a high purity and indicate no degradation of the technical properties of the recycled polymers.

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Synthesis, characterization and corrosion protection properties of polyN-(p-bromophenyl)-2-methacrylamide-co-glycidyl methacrylate on low nickel stainless steel

Journal of Polymer Engineering ◽

10.1515/polyeng.2011.042 ◽

2011 ◽

Vol 31 (2-3) ◽

Cited By ~ 2

Author(s):

Sakvai Mohammed Safiullah ◽

Deivasigamani Thirumoolan ◽

Kottur Anver Basha ◽

K. Mani Govindaraju ◽

Dhanraj Gopi ◽

...

Keyword(s):

Stainless Steel ◽

Corrosion Protection ◽

Glycidyl Methacrylate ◽

Electrochemical Impedance ◽

Thermo Gravimetric Analysis ◽

Gel Permeation Chromatography ◽

Gravimetric Analysis ◽

Scanning Calorimetry ◽

Protection Efficiency ◽

Ft Ir

Abstract The synthesis of copolymers from different feed ratios of N-(p-bromophenyl)-2- methacrylamide (PBPMA) and glycidyl methacrylate (GMA) was achieved by using free radical solution polymerization technique and characterized using FT-IR, 1H and 13C NMR spectroscopy. The thermal stability of the synthesized copolymers was studied using thermo-gravimetric analysis (TGA) and differential scanning calorimetry (DSC). The molecular weight of the copolymer is determined by gel permeation chromatography (GPC). The corrosion performances of low nickel stainless steel specimens dip coated with different composition of copolymers were investigated in 0.5 M H2SO4 using potentiodynamic polarization and electrochemical impedance spectroscopic (EIS) techniques. The polarization and impedance measurements showed different corrosion protection efficiency with change in composition of the copolymers. It was found that the corrosion protection properties are owing to the barrier effect of the polymer layer covered on the low nickel stainless steel surfaces. However, it is observed that the mole ratio of PBPMA and GMA plays a major role in the protective nature of the copolymer.

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Synthesis and Characterization of a Multifunctional Conjugated Polymer

Advances in Condensed Matter Physics ◽

10.1155/2018/9427460 ◽

2018 ◽

Vol 2018 ◽

pp. 1-9 ◽

Cited By ~ 2

Author(s):

Emerson C. G. Campos ◽

Cristiano Zanlorenzi ◽

Bruno F. Nowacki ◽

Gabriela M. Miranda ◽

Denis A. Turchetti ◽

...

Keyword(s):

Conjugated Polymer ◽

Molar Mass ◽

Photophysical Properties ◽

Gel Permeation Chromatography ◽

Thermal Characterization ◽

Polymer Structure ◽

Synthesis And Characterization ◽

Metallic Ions ◽

Scanning Calorimetry

This work reports the synthesis and characterization of a conjugated polymer based on fluorene and terpyridine, namely, poly[(9,9-bis(3-((S)-2-methylbutylpropanoate))fluorene-alt-6,6′-(2,2′:6′,2′′-terpyridin-6-yl)] (LaPPS71). The structure was characterized by 1H and 13C nuclear magnetic resonance (NMR) and Fourier-transform infrared (FTIR) spectroscopy. The molar mass was measured by gel permeation chromatography (GPC). As thermal characterization, the glass transition temperature (Tg) was measured by differential scanning calorimetry (DSC). The polymer structure contains two sites capable of complexation with metallic ions, affording the possibility of obtainment of independent or electronically coupled properties, depending on the complexation site. The photophysical properties were fully explored in solution and solid state, presenting ideal results for the preparation of various metallopolymers, in addition to potential application as a metamaterial, due to the presence of the chiral center in the side chains of the polymer.

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Characterization of bi-layered magnetic nanoparticles synthesized via two-step surface-initiated ring-opening polymerization

Pure and Applied Chemistry ◽

10.1515/pac-2015-0607 ◽

2015 ◽

Vol 87 (11-12) ◽

pp. 1085-1097 ◽

Cited By ~ 2

Author(s):

Li Wang ◽

Stefan Baudis ◽

Karl Kratz ◽

Andreas Lendlein

Keyword(s):

Magnetic Nanoparticles ◽

Ring Opening ◽

Average Molecular Weight ◽

Polymer Networks ◽

Gel Permeation Chromatography ◽

Degree Of Crystallinity ◽

Scanning Calorimetry ◽

H Nmr ◽

Transmission Electron

AbstractA versatile strategy to integrate multiple functions in a polymer based material is the formation of polymer networks with defined nanostructures. Here, we present synthesis and comprehensive characterization of covalently surface functionalized magnetic nanoparticles (MNPs) comprising a bi-layer oligomeric shell, using Sn(Oct)2 as catalyst for a two-step functionalization. These hydroxy-terminated precursors for degradable magneto- and thermo-sensitive polymer networks were prepared via two subsequent surface-initiated ring-opening polymerizations (ROPs) with ω-pentadecalactone and ε-caprolactone. A two-step mass loss obtained in thermogravimetric analysis and two distinct melting transitions around 50 and 85°C observed in differential scanning calorimetry experiments, which are attributed to the melting of OPDL and OCL crystallites, confirmed a successful preparation of the modified MNPs. The oligomeric coating of the nanoparticles could be visualized by transmission electron microscopy. The investigation of degrafted oligomeric coatings by gel permeation chromatography and 1H-NMR spectroscopy showed an increase in number average molecular weight as well as the presence of signals related to both of oligo(ω-pentadecalactone) (OPDL) and oligo(ε-caprolactone) (OCL) after the second ROP. A more detailed analysis of the NMR results revealed that only a few ω-pentadecalactone repeating units are present in the degrafted oligomeric bi-layers, whereby a considerable degree of transesterification could be observed when OPDL was polymerized in the 2nd ROP step. These findings are supported by a low degree of crystallinity for OPDL in the degrafted oligomeric bi-layers obtained in wide angle X-ray scattering experiments. Based on these findings it can be concluded that Sn(Oct)2 was suitable as catalyst for the preparation of nanosized bi-layered coated MNP precursors by a two-step ROP.

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Adhesive Performance of Acrylic Pressure-Sensitive Adhesives from Different Preparation Processes

Polymers ◽

10.3390/polym13162627 ◽

2021 ◽

Vol 13 (16) ◽

pp. 2627

Author(s):

Irene Márquez ◽

Núria Paredes ◽

Felipe Alarcia ◽

José Ignacio Velasco

Keyword(s):

Average Particle Size ◽

Gel Permeation Chromatography ◽

Shear Resistance ◽

Deformation Energy ◽

Average Particle ◽

Scanning Calorimetry ◽

Pressure Sensitive Adhesives ◽

Pressure Sensitive ◽

Monomeric Composition ◽

Adhesive Performance

A series of pressure-sensitive adhesives (PSAs) was prepared using a constant monomeric composition and different preparation processes to investigate the best combination to obtain the best balance between peel resistance, tack, and shear resistance. The monomeric composition was a 1:1 combination of two different water-based acrylic polymers—one with a high shear resistance (A) and the other with a high peel resistance and tack (B). Two different strategies were applied to prepare the adhesives: physical blending of polymers A and B and in situ emulsion polymerization of A + B, either in one or two steps; in this last case, by polymerizing A or B first. To characterize the polymer, the average particle size and viscosity were analyzed. The glass transition temperature (Tg) was determined by differential scanning calorimetry (DSC). The tetrahydrofuran (THF) insoluble polymer fraction was used to calculate the gel content, and the soluble part was used to determine the average sol molecular weight by means of gel permeation chromatography (GPC). The adhesive performance was assessed by measuring tack as well as peel and shear resistance. The mechanical properties were obtained by calculating the shear modulus and determination of maximum stress and the deformation energy. Moreover, an adhesive performance index (API) was designed to determine which samples are closest to the requirements demanded by the self-adhesive label market.

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Synthesis and characterization of novel methacrylate copolymers having pendant piperonyl group: monomer reactivity ratio, thermal degradation kinetics, and biological activity

Polymers and Polymer Composites ◽

10.1177/09673911211053978 ◽

2021 ◽

Vol 29 (9_suppl) ◽

pp. S1432-S1445

Author(s):

Ibrahim Erol ◽

Bayram Gencer ◽

Zeki Gurler

Keyword(s):

Biological Activity ◽

Degradation Kinetics ◽

Gel Permeation Chromatography ◽

Reactivity Ratio ◽

Thermal Degradation Kinetics ◽

Scanning Calorimetry ◽

Molecular Weights ◽

Monomer Reactivity Ratio ◽

Bacteria And Fungi ◽

Photo Stability

In this study, 2-{[(2H-1,3-benzodioxol-5-yl)methyl]amino}-2-oxoethyl 2-methylprop-2-enoate (BMAOME) monomer was synthesized, and copolymers were prepared with glycidyl methacrylate (GMA). Structural characterizations of the compounds were performed using FTIR, 1H-, and 13C-NMR techniques. Monomer reactivity ratio values were calculated by Finemann–Ross (FR) and Kelen–Tudos (KT) methods. The Tg value of the polymers was determined by differential scanning calorimetry (DSC) and their thermal stability was determined by thermogravimetric analysis (TGA). The molecular weights (w and n) and polydispersity index of the polymers were determined by gel permeation chromatography. The Ea value of thermal decomposition was determined by using the Ozawa and Kissinger methods. The photo-stability of the copolymers was investigated. Furthermore, the photo-stability of the copolymers and the biological activity of polymers against different types of bacteria and fungi were investigated.

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Halogenated methacrylate-based aluminum oxide (Al2O3) nanocomposites

Journal of Thermoplastic Composite Materials ◽

10.1177/0892705715610410 ◽

2015 ◽

Vol 30 (6) ◽

pp. 762-772

Author(s):

Kathikar Abdul Wasi ◽

Sakvai Mohammed Safiullah ◽

Kottur Anver Basha

Keyword(s):

Aluminum Oxide ◽

Polymer Matrix ◽

Glycidyl Methacrylate ◽

Morphological Changes ◽

Thermal Studies ◽

Gel Permeation Chromatography ◽

Decomposition Temperature ◽

Scanning Calorimetry ◽

Initial Decomposition Temperature ◽

Mixing Techniques

The aim of the work is to prepare the halogenated methacrylate-based polymer nano-aluminum oxide (Al2O3) composites and to study the effect of incorporated nano-Al2O3 on morphological and thermal studies. A functional 2,4,6-tribromophenyl methacrylate- co-glycidyl methacrylate copolymer microspheres (poly(TBPMA- co-GMA); pTG) by emulsion solvent evaporation techniques, whereas (2,4,6-tribromophenyl methacrylate- co-glycidyl methacrylate)-Al2O3 nanocomposites (pTG-Al2O3 nanocomposites) were prepared by solution mixing techniques. The pTG and its Al2O3 nanocomposites were structurally characterized by Fourier transform infrared (FTIR) spectroscopy. Thermal studies of pTG and its Al2O3 nanocomposites were carried out by thermogravimetric analysis and differential scanning calorimetry . The molecular weight of the pTG was determined by gel permeation chromatography. The size distribution and morphology of the pTG and its Al2O3 nanocomposites were determined by scanning electron microscopy (SEM). The FTIR results reveal that there is no significant interaction between the polymer matrix and Al2O3 nanoparticle. The significant increase in the initial decomposition temperature and glass transition temperature of pTG-Al2O3 nanocomposites compared to its polymer was due to the incorporation of nano-Al2O3 in the polymer matrix. The SEM observation provides the information about the morphological changes that arise in polymer matrix due to the incorporation of nano-Al2O3.

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