Home / Advanced Search

  • Title/Keywords

  • Author/Affliations

  • Journal

  • Article Type

  • Start Year

  • End Year

Update SearchingClear
  • Articles
  • Online
Search Results (39)
  • Open Access

    ARTICLE

    Color and Gloss Changes of a Lignin-Based Polyurethane Coating under Accelerated Weathering

    Fatemeh Hassani Khorshidi1, Saeed Kazemi Najafi1, Farhood Najafi2,*, Antonio Pizzi3,*, Dick Sandberg4, Rabi Behrooz1

    Journal of Renewable Materials, Vol.12, No.2, pp. 305-323, 2024, DOI:10.32604/jrm.2023.043953

    Abstract The purpose of this research study was to investigate the properties of polyurethane coatings based on lignin nano-particles. For this purpose, the prepared coatings were applied to pine wood surfaces and weathered artificially. Subsequently, color and gloss of the coatings were measured before and after the weathering test. Field emission scanning electron microscopy (FE-SEM) micrographs prepared from the coatings showed that the average size of nano-particles in the polyurethane substrate was approximately 500 nm. Nuclear magnetic resonance (13C-NMR) spectroscopy showed that strong urethane bonds were formed in the nano-lignin-based polyurethane. Differential calorimetric analysis (DSC) test revealed that the glass-transition temperature… More > Graphic Abstract

    Color and Gloss Changes of a Lignin-Based Polyurethane Coating under Accelerated Weathering

  • Open Access

    ARTICLE

    α7nAChR inhibition by methyllycaconitine citrate promotes cell pyroptosis by triggering the polyol pathway in cervical cancer cells

    JUNYING XU1,#, PING LI1,#, GE WANG2, DAQIANG YE1,*, XIUFU TANG3,*

    BIOCELL, Vol.48, No.2, pp. 283-291, 2024, DOI:10.32604/biocell.2023.045429

    Abstract Background: α7 nicotinic acetylcholine receptor (α7nAChR) has been demonstrated to be involved in numerous of inflammatory diseases. Cell pyroptosis is a kind of cell death accompanied by inflammation. Objectives: The objective of this work is to explore the function of α7nAChR on cell pyroptosis in cervical cancer cells. Methods: Immunoblotting, quantitative polymerase chain reaction, and enzyme-linked immunosorbent assay were employed to examine the function of α7nAChR on cell pyroptosis and metabolic changes. Results: Herein, we found that α7nAChR inhibition led to cell pyroptosis in HeLa and SiHa of cervical cancer cells, which was attributed to the upregulation of the polyol… More >

  • Open Access

    ARTICLE

    Effect of Amine Type on Lignin Modification to Evaluate Its Reactivity in Polyol Construction for Non-Isocyanate Polyurethanes (NIPU)

    Saeed Kazemi Najafi1, Farhood Najafi2, Antonio Pizzi3,*, Fatemeh Hassani Khorshidi1,*, Rabi Behrooz1

    Journal of Renewable Materials, Vol.11, No.5, pp. 2171-2189, 2023, DOI:10.32604/jrm.2023.027835

    Abstract Polyols are groups of organic compounds which contain carbon and are randomly linked to other atoms, especially carbon-carbon and carbon-hydrogen. These compounds are mainly used as reactants to make other polymers. Among biopolymers, lignin is regarded as the base of a new polymer in polyol construction. The present study aimed to investigate the effects of amine type (diethylenetriamine and ethylenediamine) on the modification of lignin-based polyols, so as to provide an alternative to petroleum polyols and, in turn, increase functional groups and reduce their harm to humans’ health and the environment. To this aim, first, lignin was extracted from raw… More > Graphic Abstract

    Effect of Amine Type on Lignin Modification to Evaluate Its Reactivity in Polyol Construction for Non-Isocyanate Polyurethanes (NIPU)

  • Open Access

    ARTICLE

    Preparation and Properties of Vegetable-Oil-Based Thioether Polyol and Ethyl Cellulose Supramolecular Composite Films

    Ruyu Yan1,2,3,4, Jian Fang1,*, Xiaohua Yang2,3,4,5,6, Na Yao2,3,4,5,6, Mei Li2,3,4,5,6, Yuan Nie2,3,4,5,6, Tianxiang Deng2,3,4,5,6, Haiyang Ding2,3,4,5,6, Lina Xu2,3,4,5,6, Shouhai Li2,3,4,5,6,*

    Journal of Renewable Materials, Vol.11, No.4, pp. 1937-1950, 2023, DOI:10.32604/jrm.2023.025126

    Abstract Ethyl cellulose (EC), an important biomass-based material, has excellent film-forming properties. Nevertheless, the high interchain hydrogen bond interaction leads to a high glass transition temperature of EC, which makes it too brittle to be used widely. The hydroxyl group on EC can form a supramolecular system in the form of a non-covalent bond with an effective plasticizer. In this study, an important vegetable-oil-based derivative named dimer fatty acid was used to prepare a novel special plasticizer for EC. Dimer-fatty-acid-based thioether polyol (DATP) was synthesized and used to modify ethyl cellulose films. The supramolecular composite films of DATP and ethyl cellulose… More > Graphic Abstract

    Preparation and Properties of Vegetable-Oil-Based Thioether Polyol and Ethyl Cellulose Supramolecular Composite Films

  • Open Access

    ARTICLE

    Bio-Based High Functionality Polyols and Their Use in 1K Polyurethane Coatings

    Thomas J. Nelson, Lindsey Bultema, Neal Eidenschink, Dean C. Webster*

    Journal of Renewable Materials, Vol.1, No.2, pp. 141-153, 2013, DOI:10.7569/JRM.2013.634113

    Abstract Bio-based polyols with high functionality were successfully synthesized by ring-opening epoxidized sucrose esters of soybean oil with methanol under acidic conditions, and were subsequently formulated with blocked isocyanates to form one package polyurethanes (1KPU). The bio-based polyols were characterized by gel permeation chromatography (GPC), Fourier transform infrared (FTIR) spectroscopy, proton nuclear magnetic resonance (1 H-NMR) spectroscopy, and Brookfi eld viscosity. Bio-based coatings were prepared by formulating the polyols with blocked polyisocyanates based on isophorone diisocyanate (IPDI) and hexamethylene diisocyanate (HDI). Two types of bio-based polyols were synthesized and the ratio of NCO:OH functional groups was varied to explore the effect… More >

  • Open Access

    ARTICLE

    Revalorisation of Posidonia Oceanica as Reinforcement in Polyethylene/Maleic Anhydride Grafted Polyethylene Composites

    D. Puglia*, R. Petrucci, E. Fortunati, F. Luzi, J.M. Kenny, L. Torre

    Journal of Renewable Materials, Vol.2, No.1, pp. 66-76, 2014, DOI:10.7569/JRM.2013.634134

    Abstract Posidonia Oceanica waste was used as reinforcement in a polyethylene matrix and the obtained composites were characterised by a tensile test and morphological analysis. The fi brous material derived from P. Oceanica wastes was characterised by morphological, thermal and chemical analysis, and a subsequent treatment with sodium hydroxide (NaOH) at different weight content (2, 5 and 10 wt%) was considered as an optimised method for surface modifi cation of pristine fi bres (PO). The TGA analysis and morphological investigation of the treated fi bres selected the 5 wt% of NaOH as the best treatment. Matrix compatibilisation with maleic anhydride grafted… 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 highest impact in the following… More >

  • Open Access

    ARTICLE

    Photodegradation of Polyurethane Foam Obtained from Renewable Resource–Pulp Production Byproducts

    A. Paberza*, L. Stiebra, U. Cabulis

    Journal of Renewable Materials, Vol.3, No.1, pp. 19-27, 2015, DOI:10.7569/JRM.2014.634138

    Abstract Rigid polyurethane foams were obtained from pulp production byproducts. Three different polyols were used—tall oil polyol, lignopolyol and commercially available polyol for comparison. The obtained rigid polyurethane foams underwent photodegradation at 60°C temperature and at 0.89 W/m2 intensity of UV light radiation up to 1000 h. Changes in chemical structure were observed by Fourier Transform Infrared Spectroscopy and Scanning Electron Microscopy was used to study changes in cell morphology. Spectrophotometery was used to determine yellowing of the foams. Results showed that the thickness of degraded layer for rigid polyurethane foams obtained from pulp production byproducts was ~25% less than for… More >

  • Open Access

    ARTICLE

    Flexible Polyurethane Foams Modifi ed with New Bio-Polyol Based on Rapeseed Oil

    Sławomir Michałowski, Aleksander Prociak*

    Journal of Renewable Materials, Vol.3, No.1, pp. 14-18, 2015, DOI:10.7569/JRM.2014.634131

    Abstract This article describes the effects of the modifi cation of polyurethane system with rapeseed oil-based polyol on the cell structure and physical-mechanical properties of conventional fl exible polyurethane foams. The foams were prepared by substituting a part of the petrochemical polyether-polyols mixture with the bio-polyol based on rapeseed oil. Selected physical-mechanical properties of these foams were examined and compared to the properties of reference foam. The properties such as apparent density, resilience, comfort factor and stress-strain characteristics were analyzed in compression tests. It was found that the modifi cation of polyurethane formulation with rapeseed oil-based polyol improves the selected properties… More >

  • Open Access

    ARTICLE

    Linseed Oil-Based Polyurethane Rigid Foams: Synthesis and Characterization

    Tamara Calvo-Correas1, Mirna A. Mosiewicki2, M. Angeles Corcuera1, Arantxa Eceiza1, Mirta I. Aranguren2,*

    Journal of Renewable Materials, Vol.3, No.1, pp. 3-13, 2015, DOI:10.7569/JRM.2014.634132

    Abstract Rigid polyurethane foams were synthesized by using a vegetable oil-based polyol and 4,4-diphenylmethane diisocyanate prepolymer as the majority of reactives,. The polyol was produced by hydroxylation of crude linseed oil with performic acid generated in situ by the reaction of hydrogen peroxide and formic acid. The characterization by FTIR, H1 NMR, iodine and hydroxyl values of the polyol and its comparison with the original linseed oil supports the success of the reaction. The reference foam was subsequently modifi ed by substituting part of the linseed oil polyol with glycerol, diethylene glycol, and a polyethylene glycol (all of them of lower… More >

Displaying 1-10 on page 1 of 39. Per Page