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Togay Ozbakkaloglu - One of the best experts on this subject based on the ideXlab platform.

  • A review of natural fiber composites: properties, modification and processing techniques, characterization, applications
    Journal of Materials Science, 2019
    Co-Authors: Aliakbar Gholampour, Togay Ozbakkaloglu
    Abstract:

    There has been much effort to provide eco-friendly and biodegradable materials for the next generation of composite products owing to global environmental concerns and increased awareness of renewable green resources. An increase in the use of natural materials in composites has led to a reduction in greenhouse gas emissions and carbon footprint of composites. In addition to the benefits obtained from green materials, there are some challenges in working with them, such as poor compatibility between the reinforcing natural fiber and matrix and the relatively High Moisture Absorption of natural fibers. Green composites can be a suitable alternative for petroleum-based materials. However, before this can be accomplished, there are a number of issues that need to be addressed, including poor interfacial adhesion between the matrix and natural fibers, Moisture Absorption, poor fire resistance, low impact strength, and low durability. Several researchers have studied the properties of natural fiber composites. These investigations have resulted in the development of several procedures for modifying natural fibers and resins. To address the increasing demand to use eco-friendly materials in different applications, an up-do-date review on natural fiber and resin types and sources, modification and processing techniques, physical and mechanical behaviors, applications, life-cycle assessment, and other properties of green composites is required to provide a better understanding of the behavior of green composites. This paper presents such a review based on 322 studies published since 1978.

Aliakbar Gholampour - One of the best experts on this subject based on the ideXlab platform.

  • A review of natural fiber composites: properties, modification and processing techniques, characterization, applications
    Journal of Materials Science, 2019
    Co-Authors: Aliakbar Gholampour, Togay Ozbakkaloglu
    Abstract:

    There has been much effort to provide eco-friendly and biodegradable materials for the next generation of composite products owing to global environmental concerns and increased awareness of renewable green resources. An increase in the use of natural materials in composites has led to a reduction in greenhouse gas emissions and carbon footprint of composites. In addition to the benefits obtained from green materials, there are some challenges in working with them, such as poor compatibility between the reinforcing natural fiber and matrix and the relatively High Moisture Absorption of natural fibers. Green composites can be a suitable alternative for petroleum-based materials. However, before this can be accomplished, there are a number of issues that need to be addressed, including poor interfacial adhesion between the matrix and natural fibers, Moisture Absorption, poor fire resistance, low impact strength, and low durability. Several researchers have studied the properties of natural fiber composites. These investigations have resulted in the development of several procedures for modifying natural fibers and resins. To address the increasing demand to use eco-friendly materials in different applications, an up-do-date review on natural fiber and resin types and sources, modification and processing techniques, physical and mechanical behaviors, applications, life-cycle assessment, and other properties of green composites is required to provide a better understanding of the behavior of green composites. This paper presents such a review based on 322 studies published since 1978.

Yi-ching Cheung - One of the best experts on this subject based on the ideXlab platform.

  • structure and properties of a 1 3 β d glucan from ultrasound degraded exopolysaccharides of a medicinal fungus
    Carbohydrate Polymers, 2014
    Co-Authors: Xia Chen, Ka Chai Siu, Yi-ching Cheung
    Abstract:

    A High molecular weight (MW) exopolysaccaride (EPS) fraction EPS1 was isolated from the fermentation broth of a medicinal fungus Cordyceps sinensis Cs-HK1 and partially degraded by High-intensity ultrasound (US) into a lower MW fraction EPS1U. EPS1U exhibited a single, symmetric peak on size exclusion chromatography with an average MW of 730kDa by light scattering analysis. It had a much lower intrinsic viscosity (1.7 versus 15.6dL/g) but a much Higher solubility in water (77.5 versus 5.1g/L) than EPS1. Based on methylation analysis and NMR spectrometry, the structure of EPS1U was deduced as a (1→3)-β-d-glucan with glucose side chains attached to O-6 position at the branching points. EPS1U showed a High Moisture Absorption capability comparable to chitosan and urea, suggesting its potential as a moisturizing agent for food and cosmeceutical application. This is the first report on a High MW (1→3)-β-d-glucan isolated from EPS produced by Cordyceps sinensis.

Muhammad Nasir - One of the best experts on this subject based on the ideXlab platform.

  • interdependence of Moisture mechanical properties and hydrophobic treatment of jute fibre reinforced composite materials
    Journal of The Textile Institute, 2017
    Co-Authors: Muhammad Haris Ameer, Khubab Shaker, Munir Ashraf, Mehmet Karahan, Yasir Nawab, Sheraz Ahmad, Muhammad Nasir
    Abstract:

    AbstractDespite cheap and sustainable in nature, the use of natural fiber composites is limited due to their High Moisture Absorption, poor fiber–matrix interface, and lack of data on evolution of properties when subjected to environmental factor such as temperature and humidity. The aim of this research is to study the interdependence of Moisture regain, hydrophobic treatment, and the mechanical properties of jute fiber-reinforced composite materials. Composite samples made from treated and untreated jute fiber-reinforced composites were exposed to humid environment and their Moisture regain, mechanical properties and fiber-matrix interface was tested at given time intervals until four weeks. The composites produced with hydrophobic treated reinforcement showed lesser Moisture regain and improvement in the tensile and flexural strengths compared to untreated fabric composite. A clear improvement in fiber-resin interface was observed by scanning electronic microscopy. The dynamic mechanical analysis of tr...

Lee, Dong Woog - One of the best experts on this subject based on the ideXlab platform.

  • Development of Poly(methyl methacrylate)-Based Copolymers with Improved Heat Resistance and Reduced Moisture Absorption
    'American Chemical Society (ACS)', 2019
    Co-Authors: Park Jintae, Baek Myung-jin, Choi, Hyun Woo, Kim, Hak Sun, Lee, Dong Woog
    Abstract:

    Poly(methyl methacrylate) (PMMA) is widely used as a transparent material for optical applications, owing to its High light transmittance. However, it exhibits poor heat resistance and High Moisture Absorption, leading to distortion and deformation upon exposure to elevated temperatures and/or Moisture. These structural changes decrease the transparency of PMMA, critically limiting its applicability. In this study, we synthesized poly(methyl methacrylate-co-styrene-co-acrylamide) (PMSAm) as a reference polymer and introduced one of four different comonomers [N-phenylmaleimide (PMI), N-cyclohexylmaleimide (CHMI), allyltrimethylsilane (ATMS), or 2,2,2-trifluoroethyl methacrylate (TF)] as a means to improve heat resistance and reduce Moisture Absorption. Four series of PMMA-based random copolymers (PMSAm???PMI, PMSAm???CHMI, PMSAm???ATMS, and PMSAm???TF) were synthesized by conventional thermal radical polymerization. All of the polymers synthesized exhibited improved heat resistance, with PMSAm???CHMI exhibiting the Highest glass transition temperature (Tg = 122.54 ??C) and 5% weight loss thermal decomposition temperature (T5d = 343.40 ??C) as well as the lowest thermal expansion coefficient (90.3 ??m m???1 ??C???1). The Highest hydrophobicity was exhibited by PMSAm???TF, with a water contact angle of 78.9??, indicating Higher hydrophobicity compared to that of pure PMMA (69.4??). More importantly, High transparency (???90%) was exhibited by all of the synthesized polymers. Thus, our copolymerization strategy successfully addresses the limitations, i.e., low heat resistance and High Moisture Absorption, of conventional PMMA-based materials