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  • Open Access


    Flexible Biofoams Based on Furanics and Fatty Acids Esterified Tannin

    Elham Azadeh1, Ummi Hani Abdullah2,3, Christine Gerardin1,*, Antonio Pizzi1,*, Philippe Gerardin1, Cesar Segovia4

    Journal of Renewable Materials, Vol.11, No.10, pp. 3625-3645, 2023, DOI:10.32604/jrm.2023.030373

    Abstract Water repellant, flexible biofoams using tannin esterified with various fatty acid chains, namely lauric, palmitic and oleic acids, by reaction with lauryl chloride, palmitoyl chloride, and oleyl chloride were developed and their characteristics compared with the equivalently esterified rigid biofoams. Glycerol, while initially added to control the reaction temperature, was used as a plasticizer yielding flexible biofoams presenting the same water repellant character that the equivalent rigid foams. Acetaldehyde was used as the cross-linking agent instead of formaldehyde, as it showed a better performance with the esterified tannin. The compression results showed a significant decrease… More >

  • Open Access


    Self-Blowing Non-Isocyanate Polyurethane Foams Based on Hydrolysable Tannins

    Elham Azadeh1, Xinyi Chen2, Antonio Pizzi2,*, Christine Gérardin1, Philip Gérardin1, Hisham Essawy3

    Journal of Renewable Materials, Vol.10, No.12, pp. 3217-3227, 2022, DOI:10.32604/jrm.2022.022740

    Abstract Non-isocyanate polyurethane (NIPU) foams using a hydrolysable tannin, also vulgarly called tannic acid, namely here commercial chestnut wood tannin extract was prepared. Compression strength did not appear to depend on the foam apparent density while the formulation composition of the NIPU foams has been shown to be more determinant. These NIPU foams appeared to be self-extinguishing once the high temperature flame is removed. The ignition time gave encouraging results but for improved fire resistance the foams may need some fire-retardant addition. FTIR spectrometry showed the formation of non-isocyanate urethane linkages. Thermogravimetric analysis indicated a good More >

  • Open Access


    Dielectric Permittivity of Rigid Rapeseed Oil Polyol Polyurethane Biofoams and Petrochemical Foams at Low Frequencies

    Ilze Beverte1,*, Vairis Shtrauss1, Aldis Kalpinsh1, Uldis Lomanovskis1, Ugis Cabulis2, Irina Sevastyanova2, Sergejs Gaidukovs3

    Journal of Renewable Materials, Vol.8, No.9, pp. 1151-1170, 2020, DOI:10.32604/jrm.2020.010215

    Abstract Early investigations of dielectric permittivity of rigid polyurethane foams at low frequencies were made on petrochemical-origin foams, mainly by means of parallel plate capacitors. In the present investigation biopolyol was synthesized from Latvia-grown rapeseeds’ oil by the transesterification method with triethanolamine, in an environmentally friendly process, without emission of harmful substances, at temperatures 175°C ± 5°C. Rigid, closed-cell rapeseed oil polyol polyurethane biofoams and petrochemical foams were made ensuring content of the renewable rapeseed oil polyol in ready foams 27 wt.%–29 wt.%. Dielectric permittivity of the polyurethane foams and the underlying monolithic petrochemical-origin polyurethane and… More >

  • Open Access


    Tannin-Based Biofoams-A Review

    Antonio Pizzi*

    Journal of Renewable Materials, Vol.7, No.5, pp. 477-492, 2019, DOI:10.32604/jrm.2019.06511

    Abstract This review details the development of tannin-based biofoams for fire resistance and acoustic insulation and details the different varieties of these foams that have been developed, from tannin-furanic self-blowing foams to tannin-furanic polyurethanes and finally non-isocyanate tannin-based-carbohydrates polyurethanes (NIPU). More >

  • Open Access


    Glucose-Biobased Non-Isocyanate Polyurethane Rigid Foams

    Xuedong Xi1,2, A. Pizzi1,*, C. Gerardin3, Guanben Du2

    Journal of Renewable Materials, Vol.7, No.3, pp. 301-312, 2019, DOI:10.32604/jrm.2019.04174

    Abstract Glucose-based non-isocyanate polyurethanes (NIPU) were prepared by reaction of glucose with dimethyl carbonate and hexamethylene diamine. These were used to prepare partially biobased polyurethane foams by reaction with NaHCO3 as a blowing agent and addition of a silane coupling agent having different functions such as coreactant and adjuvant to obtain more uniform and smaller cells. The foams were foamed and hardened by applying heat. The foams presented very limited fire resistance indicating that as for synthetic polyurethane foams the eventual use of a fire retardant appears to be necessary. The 2 hours water absorption was More >

  • Open Access


    Karanja Oil Polyol and Rigid Polyurethane Biofoams for Thermal Insulation

    M. Himabindu1, K. Kamalakar2, MSL Karuna2, Aruna Palanisamy1*

    Journal of Renewable Materials, Vol.5, No.2, pp. 124-131, 2017, DOI:10.7569/JRM.2016.634137

    Abstract Rigid polyurethane biofoams were prepared from karanja polyol which was derived by ring-opening reaction of epoxidized karanja oil. The polyol, which had a hydroxyl value of 186 mg KOH/g, was thoroughly characterized and the structure confirmed by spectral techniques. The foam formulations were developed to achieve shrinkage-free foams with water used as the blowing agent. The resulting foams were characterized for their mechanical properties like density, compression strength and flexural strength. The densities and mechanical properties, such as compression and flexural strength, varied with the amount of methylene diphenyl diisocyanate (MDI) for a fixed amount More >

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