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  • Open Access

    ARTICLE

    Feasibility Study of the Synthesis of Isocyanate-Free Polyurethanes from Catechin

    Wissem Sahmim1, Febrina Dellarose Boer1, Hubert Chapuis1, Firmin Obounou-Akong1, Antonio Pizzi2, Philippe Gérardin1, Christine Gérardin-Charbonnier1,*

    Journal of Renewable Materials, Vol.10, No.5, pp. 1175-1184, 2022, DOI:10.32604/jrm.2022.016365

    Abstract With the current trend of increasing efforts to develop non-isocyanate-based polyurethanes (NIPUs), this study aimed to check the feasibility of the development of a method using cyclic carbonate modified catechin and amine to synthesis non-isocyanate urethane with the objective to further extend these results to polyurethane synthesis. The methods used in this study consist of four steps: glycidilation of catechin, hydrolysis of epoxide, cyclic carbonate synthesis, and carbamate synthesis through condensation of butylamine. The resulting products were analyzed using FTIR (Fourier transform infrared) spectroscopy and NMR (nuclear magnetic resonance) spectroscopy. The results showed that carbamate could be successfully obtained through… More > Graphic Abstract

    Feasibility Study of the Synthesis of Isocyanate-Free Polyurethanes from Catechin

  • Open Access

    ARTICLE

    Dynamic Mechanical and Chemorheology Analysis for the Blended Epoxy System with Polyurethane Modified Resin

    Xue Xin1,#, Yu Rong1,#, Linping Su1, Zhengmei Qiu1, Chenjun Yang1, Ming Liang1,*, Ping Ji2, Guoqiang Zhong3, Zhanyong Yao1,*

    Journal of Renewable Materials, Vol.10, No.4, pp. 1081-1095, 2022, DOI:10.32604/jrm.2022.018021

    Abstract As the important matrix material, epoxy resin has been widely used in the composites for various fields. On account of the poor toughness of epoxy resin limiting their suitability for advanced applications, considerable interests have been conducted to modify the epoxy resin to meet the engineering requirements. In this study, the bio-based polyurethane (PU) modified resin was adopted to modify the pure bisphenol-A epoxy by blending method with various proportions. Aiming to illuminate the curing behavior, mechanical and thermal properties, the blended epoxy systems were characterized by viscosity-time analysis, dynamic mechanical analysis (DMA) at different frequencies and temperatures, mechanical tensile… More >

  • Open Access

    ARTICLE

    Preparation of Hollow-Porous Rosin-Based Polyurethane Microspheres with pH-Responsive Characteristics

    Caili Yu, Hao Liu, Jintao Shao, Faai Zhang*

    Journal of Renewable Materials, Vol.10, No.4, pp. 1049-1061, 2022, DOI:10.32604/jrm.2022.017315

    Abstract Preparation of polymer microspheres from naturally occurring resource is a challenge. Here, a rosin-based polyol (RAG) was used to prepare polyurethane resin (RPU) firstly, and then act as both self-assembled precursor and emulsifier, rosin based polyurethane microspheres (RPUMs) were prepared. In the process of self-emulsification, the RPU formed vesicles by self-assembly. The outer shell of the vesicle consisted of hydrophilic segments, while the inner shell contained the hydrophobic phase. After cross-linking the RPU and removal of the solvent in the core, the porous-hollow microspheres with pH-sensitive were obtained. The microspheres were characterized by optical microscope (OM), scanning electron microscopy (SEM)… More > Graphic Abstract

    Preparation of Hollow-Porous Rosin-Based Polyurethane Microspheres with pH-Responsive Characteristics

  • Open Access

    ARTICLE

    Enhanced Water Resistance Performance of Castor Oil—Based Waterborne Polyurethane Modified by Methoxysilane Coupling Agents via Thiol-Ene Photo Click Reaction

    Zhipeng He1,2, Junqi Xue1,2, Yanzi Ke1,2, Ying Luo1,2,*, Qiming Lu1,2, Yuehua Xu1,2, Chaoqun Zhang1,2,*

    Journal of Renewable Materials, Vol.10, No.3, pp. 591-604, 2022, DOI:10.32604/jrm.2022.017790

    Abstract Nowadays, waterborne polyurethanes (WPUs) prepared from renewable resources has attracted more and more attention. However, due to its structure, the prepared films easily swells in water and greatly affects the application range of WPUs. Therefore, solving the problem of water resistance is a way to improve the application range of WPUs. In this study, a series of WPU dispersions were prepared using castor oil as the bio-based polyol. Besides, the thiol-ene photo click reaction was carried out on the WPU films for silane modification. The effect of the silane modification on the chemical structures of the WPU dispersions and the… More > Graphic Abstract

    Enhanced Water Resistance Performance of Castor Oil—Based Waterborne Polyurethane Modified by Methoxysilane Coupling Agents via Thiol-Ene Photo Click Reaction

  • Open Access

    ARTICLE

    Alcoholysis of Waste Polyurethane Rigid Foam and Its Modification with Lignin for Recovery

    Xiaohua Gu1,*, Shiwei Lyu1, Siwen Liu2

    Journal of Renewable Materials, Vol.9, No.11, pp. 1913-1926, 2021, DOI:10.32604/jrm.2021.015400

    Abstract A bi-component alcoholysis agent containing propylene glycol (PG) and ethanolamine (ETA) was used to catalyst the degradation of the waste polyurethane rigid foam. The oligomer polyols obtained through degradation were used as raw materials to produce recycled polyurethane rigid foam composites with lignin as reinforcing filler. The effect of alcoholysis mass ratio on degradation was investigated by analyzing the viscosity, hydroxyl content and chemical structure of the degradation products. The effect of lignin addition on the properties of regenerated polyurethane rigid foam were investigated by analyzing water absorption rate, compressive strength, porosity, thermal stability, thermal conductivity coefficient, morphology and thermal… More >

  • Open Access

    ARTICLE

    Glycolysis Recycling of Waste Polyurethane Rigid Foam Using Different Catalysts

    Xiaohua Gu, Hongxiang Luo*, Shiwei Lv, Peng Chen

    Journal of Renewable Materials, Vol.9, No.7, pp. 1253-1266, 2021, DOI:10.32604/jrm.2021.014876

    Abstract Dramatically increasing waste polyurethane rigid foam (WPRF) draws the attention of the world. A mixture of ethylene glycol (EG) and diethylene glycol (DEG) is used as glycolysis agents. WPRF was subjected to alcoholysis using different catalysts which are titanium ethylene glycol and potassium hydroxide to obtain recycled polyol, respectively. The effect of a different catalyst on the viscosity and hydroxyl value of recycled polyol is discussed. The regenerated polyurethane (RPU) is performed using the recycled polyol. Infrared spectrum, compressive strength, apparent density, water absorption, scanning electron microscope, and thermogravimetric analysis are carried out to investigate the effect of WPRF degradation… More >

  • Open Access

    ARTICLE

    New Biobased Polyurethane Materials from Modified Vegetable Oil

    Chakib Mokhtari1, Fouad Malek1, Sami Halila2, Mohamed Naceur Belgacem3,*, Ramzi Khiari3,4,5,*

    Journal of Renewable Materials, Vol.9, No.7, pp. 1213-1223, 2021, DOI:10.32604/jrm.2021.015475

    Abstract Bio-based polyurethanes (PUs) have been occurred a large attention nowadays. It was found to be an alternative to the petrochemical based materials to the fact of their weak environmental influence, availability, good price and biodegradability. In addition, the nature shows several bio-derived compounds as raw materials for the synthesis of polyols, including the vegetable oils, polyphenol, terpene, and other bio-renewable sources. With the aim to develop a new family of biobased polyurethanes (PUs) via vegetable oils, the elaboration of new Jojoba-based PUs was performed by catalyst-free polycondensation reaction of a synthesized Jojoba diol with various diisocyanates such us toluene diisocyanate… More > Graphic Abstract

    New Biobased Polyurethane Materials from Modified Vegetable Oil

  • Open Access

    ARTICLE

    Soy Protein Isolate Non-Isocyanates Polyurethanes (NIPU) Wood Adhesives

    Xinyi Chen1,2, Antonio Pizzi1,*, Xuedong Xi1,2, Xiaojian Zhou2, Emmanuel Fredon1, Christine Gerardin3

    Journal of Renewable Materials, Vol.9, No.6, pp. 1045-1057, 2021, DOI:10.32604/jrm.2021.015066

    Abstract Soy-protein isolate (SPI) was used to prepare non-isocyanate polyurethane (NIPU) thermosetting adhesives for wood panels by reacting it with dimethyl carbonate (DMC) and hexamethylene diamine. Both linear as well as branched oligomers were obtained and identified, indicating how such oligomer structures could further cross-link to form a hardened network. Unusual structures were observed, namely carbamic acid-derived urethane linkages coupled with lactam structures. The curing of the adhesive was followed by thermomechanical analysis (TMA). It appeared to follow a two stages process: First, at a lower temperature (maximum 130°C), the growth of linear oligomers occurred, finally forming a physically entangled network.… More >

  • Open Access

    ARTICLE

    Organosolv Lignin for Non-Isocyanate Based Polyurethanes (NIPU) as Wood Adhesive

    Jaša Saražin1, Antonio Pizzi2, Siham Amirou2, Detlef Schmiedl3, Milan Šernek1,*

    Journal of Renewable Materials, Vol.9, No.5, pp. 881-907, 2021, DOI:10.32604/jrm.2021.015047

    Abstract A non-isocyanate-based polyurethane (NIPU) wood adhesive was produced from organosolv lignin, which is a bio-sourced raw material, available in large quantities and produced as a by-product of the paper industry. The formulation of this new lignin-based NIPU adhesive, which is presented, was chemically characterised by Matrix-Assisted Laser Desorption Ionization Time of Flight (MALDI ToF) mass spectrometry and by Fourier Transform Infra-Red (FTIR) spectrometry analyses. The oligomers formed were determined and showed that the three species involved in the NIPU adhesive preparation were formed by the co-reaction of the three reagents used: lignin, dimethyl carbonate, and hexamethylene diamine. Linear and branched… More >

  • 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

    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 biopolyurethane was measured with a… More >

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