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  • Open Access

    ARTICLE

    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 - 03 August 2020

    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

    ARTICLE

    Solid “Green” Polyurethanes Based on Rapeseed Oil Polyol and Modified with Glycerol and Microcellulose

    Piotr Rojek2, Mirta I. Aranguren1, Aleksander Prociak2, Mirna A. Mosiewicki1*

    Journal of Renewable Materials, Vol.4, No.4, pp. 266-274, 2016, DOI:10.7569/JRM.2016.634113

    Abstract Solid biobased polyurethanes (PUs) were prepared from a rapeseed oil-based polyol (ROPO) synthesized by epoxidation reaction followed by oxirane ring-opening with diethylene glycol. The reference material was modified by replacement of the ROPO with glycerol in different proportions and also by addition of commercial microcellulose (MC). The curing process of the reactive mixtures was monitored by rheological measurements and the analysis showed that both MC and glycerol increase the time of crossover between storage and loss modulus (liquid to solid transition in the response at 1 Hz). The completely cured polyurethanes were characterized by physical, More >

  • Open Access

    ARTICLE

    Preliminary Life Cycle Inventory of Rapeseed Oil Polyols for Polyurethane Production

    Anda Fridrihsone-Girone

    Journal of Renewable Materials, Vol.3, No.1, pp. 28-33, 2015, DOI:10.7569/JRM.2014.634136

    Abstract This study assesses present preliminary Life Cycle Inventory for rapeseed oil polyols suitable for the production of polyurethane, which is one of the most widely used polymer materials. Due to growing environmental problems, the polyurethane industry is seeking bio-based raw materials. A study was carried out for rapeseed oil triethanolamine polyol developed at Latvian State Institute of Wood Chemistry. The cradle-to-gate study was carried out with functional unit of 1 kg rapeseed oil polyol synthesized in a scaled-up pilot reactor. The results show that at the midpoint level the production of rapeseed oil has the More >

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