Yazar "Alma, Mehmet Hakki D.L.D.A.L." seçeneğine göre listele

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    Nanocellulose: Sustainable biomaterial for developing novel adhesives and composites
    (Elsevier, 2022) Candan, Zeki; Tozluoğlu, Ayhan; Gonultas, Oktay; Yildirim, Mert; Fidan, Hakan; Alma, Mehmet Hakki D.L.D.A.L.; Salan, Tufan
    Cellulose is one of the most ubiquitous and abundant natural biopolymer in the world. Nanocellulose are nanoscale cellulose-based materials isolated from trees, annual plants, agricultural residues, and algae or generated by bacteria or tunicates. Among many other sustainable nanomaterials, nanocellulose is drawing increasing interest for use in environmental remediation technologies due to its attractive properties such as excellent mechanical properties, high surface area, rich hydroxyl groups for modification, and natural properties with 100% environmental friendliness. Nanocellulose can be classified as micro/nanofibrillated cellulose (MFC/NFC), micro/nanocellulose crystals (MCC/NCC), and bacterial cellulose (BC). Nanocellulose has an existing potential as reinforcements in polymers, composite materials, and nanocomposites. Nanocellulose can be used in a variety of products such as automobile, aircraft, electronics, medical, textiles, food, optics, packaging materials, gels, composites, pharmaceuticals, bone replacement, dental products, tissue engineering, construction, coatings, wood-based composite materials, paints, papermaking, and cosmetics. © 2022 Elsevier Ltd. All rights reserved.
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    Preparation and characterization of biodegradable rigid polyurethane foams from the liquefied eucalyptus and pine woods
    (Statny Drevarsky Vyskumny Ustav sdvu4@computel.sk, 2014) Ertas, Murat; Fidan, Muhammed Said; Alma, Mehmet Hakki D.L.D.A.L.
    In this study, eucalyptus (Eucalyptus camaldulensis L.) and pine (Pinus sylvestris L.) woods were liquefied using the the blended solvents mixture of polyethylene glycol PEG-400/glycerin in the presence of sulfuric acid as a catalyst at 140-160°C for 120 min. The insoluble parts in the liquefied eucalyptus and pine were found as 17.8 and 5.5 wt. %, respectively. The acid and hydroxyl numbers of the liquefied eucalyptus and pine were determined and compared with each other. Polyurethane-type rigid foams (RPUFs) were successfully prepared by a co-polymerization of the liquefied woods (LWs) and polymeric methylene diphenylene diisocyanate (PMDI). The compressive strength (120 to 250 kPa), the modulus of elasticity (1 to 6 MPa), the density (20 to 50 kg.nr-3) and thermal conductivity (0.0352 to 0.0374 W.mK -1) of the RPUFs prepared from the LWs were found to be almost comparable to those of the synthetic foams. Furthermore, the biodegradability of the biomass-based foams was higher than that of the synthetic ones.