Search Results Heading

MBRLSearchResults

mbrl.module.common.modules.added.book.to.shelf
Title added to your shelf!
View what I already have on My Shelf.
Oops! Something went wrong.
Oops! Something went wrong.
While trying to add the title to your shelf something went wrong :( Kindly try again later!
Are you sure you want to remove the book from the shelf?
Oops! Something went wrong.
Oops! Something went wrong.
While trying to remove the title from your shelf something went wrong :( Kindly try again later!
    Done
    Filters
    Reset
  • Discipline
      Discipline
      Clear All
      Discipline
  • Is Peer Reviewed
      Is Peer Reviewed
      Clear All
      Is Peer Reviewed
  • Item Type
      Item Type
      Clear All
      Item Type
  • Subject
      Subject
      Clear All
      Subject
  • Year
      Year
      Clear All
      From:
      -
      To:
  • More Filters
      More Filters
      Clear All
      More Filters
      Source
    • Language
304,381 result(s) for "Polymer Sciences"
Sort by:
Production of Polymer Hydrogel Composites and Their Applications
Hydrogels are three-dimensional cross-linked stable network insoluble in water, which gives them a remarkable capacity to absorb both water and biological fluids. Hydrogel has been synthesized from natural or synthetic polymers and/or monomers, which have made tremendous advancements in many different applications. Composite hydrogel is a type of hydrogel prepared by grafting hydrophilic groups, such as hydroxyl (–OH), carboxylic acid (–COOH), imide (–CONH), sulfonic acid (–SO3H), amine (–NH2), and amide (–CONH2), into the polymer chain’s backbone and adding some additives such as kaolin, zeolite, or even different types of nanoparticles. Whereas the polymeric composite hydrogels exhibit stimuli for different properties such as pH, temperature, or light, which may affect swelling, mechanical properties, and self-healing, which in turn play vital roles in different areas. Hence, numerous efforts have been made to synthesize polymer-based composited hydrogels via physical or chemical crosslinking techniques to enhance their physiochemical, biological, and many other properties. Many researchers are currently paying attention to hydrogels and their applications, including wastewater treatment and purification, medical and biomedical applications, agricultural applications, and many other industrial applications. The aim of this review is to summarize the classification of composite hydrogels based on their chemical and physical crosslinking techniques, in addition to the different polymers and additives used to prepare composite hydrogels. Furthermore, the impact of hydrogel on health and the environment has been discussed. Other significant issues were also presented, including the challenges that face hydrogel production and application, which have been discussed.
A review on poly lactic acid (PLA) as a biodegradable polymer
Biodegradable plastics are among the most promising materials to replace conventional petroleum-based plastics that have caused many adverse impacts on the environment, such as pollution (land, water, etc.) and global warming. Among a range of biodegradable plastics, poly lactic acid (PLA) is not only widely available but also safe to be decomposed after its usage without polluting the environment. PLA is also in parity with other conventional plastics such as PP, PET in terms of various properties suitable for industrial usage such as mechanical, physical, biocompatibility and processability. Thus, PLA has become the most used biopolymers in many industries such as agriculture, automotive and packaging by having these characteristics. Its higher demand has contributed to a stable increment in the global PLA market. In fact, over the years, the market for PLA has grown up and will keep on expanding in the future. Overall, the PLA-based bioplastic would be an excellent substitute for the existing conventional plastics in various applications, hence will serve to protect the environment not only from pollution but also work as a sustainable and economical product. This paper will review all the recent related works and literature on PLA as the biodegradable material regarding its properties, usability, productivity and substitute.
Thermoplastic Starch (TPS)/Polylactic Acid (PLA) Blending Methodologies: A Review
Polylactic acid (PLA) and thermoplastic starch (TPS) are biodegradable polymers of biological origin, and the mixture of these polymers has been studied due to the desirable mechanical properties of PLA and the low processing cost of TPS. However, the TPS/PLA combination is thermodynamically immiscible due to the poor interfacial interaction between the hydrophilic starch granules and the hydrophobic PLA. To overcome these limitations, researchers studied the modification, processing, and properties of the mixtures as a strategy to increase the compatibility between phases. This review highlights recent developments, current results, and trends in the field of TPS/PLA-based compounds during the last two decades, with the main focus of improving the adhesion between the two components. The TPS/PLA blends were classified as plasticized, compatible, reinforced and with nanocomposites. This article presents, based on published research, TPS/PLA combinations, considering different methods with significant improvements in mechanical properties, with promising developments for applications in food packaging and biomedicine.
A comprehensive review on polymer matrix composites: material selection, fabrication, and application
Polymer matrix composites have always piqued the curiosity of the scientific, technological communities and are being recognized as the best option for a wide range of engineering applications owing to their superior mechanical qualities, namely stiffness and high specific strength. In addition, these materials offer useful design flexibility and comparatively better fatigue and corrosion resistance than many other materials. These are thus recognized as advanced composite materials due to their superior mechanical properties and comparative ease of fabrication. As a result, manufacturers have turned towards these advanced composites for a wide range of applications in a variety of industries. A manufacturer or designer must choose appropriate constituents of a composite for a particular application while considering all the composite’s properties. This stands as one of the main objectives of this review, i.e. to explore various matrices and reinforcement combinations used for different applications taking their properties into accord. This extensive analysis includes a detailed review of certain selective fabrication techniques. In addition to that, polymer matrix composites’ numerous applications in today’s environment are also discussed, as well as the challenges that they pose in diverse contexts. Through this review, researchers will achieve a better understanding of the significance of these materials and their adaptability in various applications.
Ionic conductivity enhancement of PVA: carboxymethyl cellulose poly-blend electrolyte films through the doping of NaI salt
In this paper, we report the effect of doping sodium iodide (NaI) salt into a polymer blend matrix of sodium carboxymethyl cellulose (NaCMC) and poly(vinyl alcohol) (PVA). Solution casting approach was used to prepare solid polymer electrolyte (SPE) films. The films were characterized by Fourier-transform infrared spectroscopy (FTIR), X-Ray diffraction (XRD), electrical impedance spectroscopy, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). XRD showed that NaI incorporation decreased the crystallinity of NaCMC/PVA-based SPE. FTIR technique confirmed the complexation of salt with polymer matrix due to the formation of the coordination bond between Na + and –OH group and hydrogen bond between I − and –CH group. The sample with 30 wt% NaI showed the highest conductivity of 2.52 × 10 –3 S cm −1 , strongly influenced by the highest charge concentration ( n ) , not its mobility ( μ ). DSC analysis revealed an increase in glass transition temperature ( T g ) with increasing salt content. TGA studies showed a decrease in thermal stability with salt inclusion. The transference number was found to be 0.99 for the highest conducting sample showing the primary charge carriers are ions. The highest conducting sample exhibited a mechanical strength of 15.42 MPa at room temperature, and it has been used to fabricate a battery to evaluate its suitability in energy storage devices. Graphical abstract Graphical abstract created with https://biorender.com .
Cellulose and the role of hydrogen bonds: not in charge of everything
In the cellulose scientific community, hydrogen bonding is often used as the explanation for a large variety of phenomena and properties related to cellulose and cellulose based materials. Yet, hydrogen bonding is just one of several molecular interactions and furthermore is both relatively weak and sensitive to the environment. In this review we present a comprehensive examination of the scientific literature in the area, with focus on theory and molecular simulation, and conclude that the relative importance of hydrogen bonding has been, and still is, frequently exaggerated.
Cellulose from the green macroalgae Ulva lactuca: isolation, characterization, optotracing, and production of cellulose nanofibrils
We report (1) successful extraction and characterization of cellulose from northern hemisphere green macroalgae Ulva lactuca (Ulva fenestrata) collected along the Swedish west coast and cultivated indoors under controlled conditions, followed by (2) its utilization in the production of lignin-free cellulose nanofibrils (CNF). Cellulose was extracted by sequential treatment with ethanol, hydrogen peroxide, sodium hydroxide, and hydrochloric acid, yielding a cellulose-rich insoluble fraction. The extracted cellulose was disintegrated into CNF using a mechanical homogenization process without any further enzymatic pre-treatments. In addition, regenerated cellulose was prepared. XRD characterization of the CNF showed characteristic peaks for the cellulose I allomorph and confirmed that the nanofibrils were semicrystalline with a crystallinity index of 48%. Regenerated cellulose was mostly amorphous with an XRD pattern indicating the presence of the cellulose II allomorph. The cellulose fractions were essentially free from inorganic substances and thermally stable up to around 260 °C. Structural mapping with CP-MAS 13C-NMR sustains the cellulose content of CNF and regenerated cellulose, respectively, yet ion chromatography identified the presence of 10–15% xylose in the fractions. Optotracing was used as a novel and non-disruptive tool to selectively assess the polysaccharide composition of the cellulose fractions and produced CNF aiming to shed light on this hitherto non-resolved origin of xylose in Ulva cell wall matter. Fluorescence excitation and emission spectra of a panel of 4 oligothiophenes identified and verified the presence of cellulose and sustain the conclusion that the isolated fractions consist of cellulose intertwined with a small amount of a xylose-containing glucan copolymer.Graphic abstract
A review of advances in the preparation and application of polyaniline based thermoset blends and composites
For several decades, forming blend and composite of polyaniline (PANI) with insulating polymers has been a widely studied research area because of the potential applications of such blends, which have a unique combination of mechanical properties, the processability of conventional polymers and the electrical property of conducting polymers. The current review paper will emphasize PANI composites or blends with thermosetting polymer matrices. The enhanced electro-mechanical properties of the blends and composites depend on the uniform dispersion of the PANI particle in polymer matrix. Therefore, considerable studies have focused on improving the distribution of PANI particles within the thermoset matrices. In this review paper, all the parameters and conditions that influence the surface morphology and application of PANI thermoset blends and composites will be described systematically. Recent progress on PANI based thermoset system with multifunctional ternary composites research will be highlighted in this paper. Furthermore, encouraging applications of different PANI thermoset composites and blends are discussed, such as flame-retardant materials, lightning damage suppression, metal ion removal, anticorrosive coating, electromagnetic shielding, conductive adhesives, and sensing materials.
Adsorption of Dyes Using Poly(vinyl alcohol) (PVA) and PVA-Based Polymer Composite Adsorbents: A Review
In recent years, polymeric adsorbent is gaining more interest over classical adsorbents such as clays and activated carbon due to its tunable physicochemical properties, structural diversity, reusability and selectivity. Therefore, the aim of this article is to summarize the available information on the adsorption studies of dyes using PVA and PVA-based polymer composite adsorbents. These materials were reviewed with emphasis on the experimental parameters (initial dye concentration, pH, adsorbent dosage etc.) and outcomes of the various adsorption studies were discussed. Furthermore, the isotherm models, kinetic and thermodynamic of the adsorption studies involved were also summarized. This review outlines the rationale for using the PVA-based composite adsorbents which have demonstrated good removal efficiency for several dyes. Future perspectives of the research work are also being suggested.Graphic Abstract