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    A Study on Physical, Morphological and Antibacterial Properties of Bio Polymers Reinforced Polyvinyl Acetate Foams
    (Univ Fed Sao Carlos, Dept Engenharia Materials, 2022) Yildirim, Nadir; Ozen, Ertan; Ergun, Mehmet Emin; Dalkilic, Berk
    In this study, foaming-agent free novel polyvinyl acetate (PVAc) foams reinforced with bio polymers were manufactured through freeze-drying technique. The physical, morphological and antibacterial properties of foams which were reinforced with different ratio of zinc borate and water-soluble chitosan were investigated according to relevant standards. The PVAc foams showed low densities (0.12 g/cm3 ??? 0.21 g/cm3) and high porosity rates (87.50% - 79.05%). The results showed that although the foams have no antibacterial character against Escherichia Coli, they have antibacterial character against Staphylococcus Aureus bacteria. This study mainly focusses on physical and morphological properties of the foams. However, researchers also performed accelerated weathering tests to determine its usability in different industries. The effects of accelerated weathering on the surface of foams were investigated by measuring surface color. The highest color difference was determined 8.09. This foam can be used as a low-density packaging material and/or medical box with its promising physical and morphological properties with hazardous-chemical free structure.
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    Öğe
    Fire-retardant bioproducts for green buildings
    (Woodhead Publ Ltd, 2020) Yildirim, Nadir; Erdonmez, Fatma Saime; Ozen, Ertan; Avci, Erkan; Yeniocak, Mehmet; Acar, Mehmet; Dalkilic, Berk
    [Abstract Not Available]
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    Öğe
    Manufacture of wood fiber reinforced polyvinyl acetate rigid foams
    (2020) Ergün, Mehmet Emin; Özen, Ertan; Yildirim, Nadir; Dalkılıç, Berk
    In this work, rigid foams designed and manufactured using the freezedrying technique were made from polyvinyl acetate (PVAc), bleachedkraft pulp and unbleached kraft pulp. The rigid foams designed asan environmentally-friendly product with no pentane or hydrochlorofluorocarbon included in the manufacturing process. The PVAcbased foams were reinforced with different kraft pulp contents. Theirperformance properties such as compressive and flexural strength,physical and morphological properties were investigated according torelevant standards. The foam densities ranged from 0,017 g/cm3 with%17,65 coefficient of variation (CV) to 0,137 g/cm3 with %2,33 CV.The compression resistance was found between 0,001 N/mm2 with%50,00 CV and 0,03 N/mm2 with %5,98 CV. The flexural resistancewas found between 0,005 N/mm2 with %20,00 CV and 0,11 N/mm2with %6,06 CV. Optimum properties were observed at B-4 (PVAc/Bleached Kraft pulp 1/0.8). Bleached kraft pulp reinforcement gavebetter results on performance characteristics of foam materials compared to unbleached kraft pulp reinforcement. Overall test resultsshowed that the PVAc based rigid foams have promising results.
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    Öğe
    Mechanical and thermal properties of polyvinyl acetate foams reinforced with biopolymers
    (Sage Publications Ltd, 2023) Ergun, Mehmet Emin; Ozen, Ertan; Yildirim, Nadir; Dalkilic, Berk; Baysal, Ergun
    The study developed and designed polyvinyl acetate (PVAc) foams using advanced freeze-drying technology, which exhibited good heat-insulating ability, flame retardancy, and mechanical properties. Different combinations of bleach kraft pulp, water-soluble chitosan, and zinc borate were used to reinforce the foams. The foams exhibited desirable compression and flexural properties, with compression strength and compression modulus ranging from 0.01 MPa to 0.08 MPa and 0.05 MPa to 0.29 MPa, respectively, while flexural strength and flexural modulus ranged from 0.12 MPa to 5.37 MPa and 9.86 MPa to 260,85 MPa, respectively. The use of zinc borate as a reinforcement resulted in improved thermal properties and reduced mass loss at 600 & DEG;C by 20.69%. Thermal conductivity tests indicated that the foams had low thermal conductivity values ranging from 0.037 W/mK to 0.074 W/mK. The foams with zinc borate (60 g/L) and high molecular weight water-soluble chitosan (70 g/L) reinforcement exhibited high limiting oxygen index (LOI) of 28.72%. Overall, the results suggest that the PVAc foams could serve as a promising sustainable alternative in thermal insulation and construction fields.