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  • Open Access

    ARTICLE

    Graphene-Based Active Tunable Metasurfaces for Dynamic Terahertz Absorption and Polarization Conversion

    Haoran Wei, Tian Ji, Jianqing Huang*

    Journal of Renewable Materials, Vol.11, No.2, pp. 731-743, 2023, DOI:10.32604/jrm.2022.022283

    Abstract Simultaneous broadband absorption and polarization conversion are crucial in many practical applications, especially in terahertz communications. Thus, actively tunable metamaterial systems can exploit the graphene-based nanomaterials derived from renewable resources because of the flexible surface conductivity and selective permeability of the nanomaterials at terahertz frequencies. In this paper, we propose a graphene-based active tunable bifunctional metasurface for dynamic terahertz absorption and polarization conversion. The graphene ring presents a certain opening angle (A) along the diagonal of the xoy plane. When A = 0°, the proposed metasurface behaves as a broadband absorber. Numerical results show the feasibility of achieving this polarization-insensitive… More >

  • Open Access

    ARTICLE

    Polymers from Renewable Resources: Perspectives in Biomedical Applications

    Andrea Morelli, Dario Puppi, Federica Chiellini*

    Journal of Renewable Materials, Vol.1, No.2, pp. 83-112, 2013, DOI:10.7569/JRM.2012.634106

    Abstract Polymers, particularly those susceptible to undergoing biodegradation under physiological environments, can be considered the materials of choice for biomedical applications such as tissue engineering, regenerative medicine, and controlled and targeted drug delivery. The development of these relatively new fi elds of biomedical research represents the driving force towards the exploitation of renewable resources for the obtainment of biobased polymeric biomaterials. This perspective article reports on the biomedical applications of three major categories of biobased polymeric materials obtained from renewable resources, namely, polysaccharides, proteins and polyesters of natural origins. Particular emphasis is given to biobased polymers that display only minor modifi… More >

  • Open Access

    ARTICLE

    Fully Renewable Thermoplastic Poly(ester urethane urea)s from Bio-based Diisocyanates

    Donglin Tang1,2, Shanmugam Thiyagarajan2,3, Bart A.J. Noordover1,*, Cor E. Koning1, Daan S. van Es3, Jacco van Haveren

    Journal of Renewable Materials, Vol.1, No.3, pp. 222-230, 2013, DOI:10.7569/JRM.2013.634116

    Abstract A series of fully renewable poly(ester urethane urea)s (PEUs) were synthesized from bio-based starting materials, e.g., the polyester diol, the diisocyanates including L-lysine diisocyanate (LDI) and isoidide diisocyanate (IIDI), the chain-extenders including 1,4-diaminobutane (bDA), diaminoisoidide (iDA) and di(aminobutyl) urea (b2 DA). It is found that the PEU based on the novel diisocyanate, IIDI, exhibits satisfactory thermal and mechanical properties. The LDI-based PEUs show less favorable thermal and mechanical properties than the IIDI-based counterpart, since the chemical structure of LDI is less regular than that of IIDI. However, by introducing a urea-containing dimeric diamine (b2 DA) instead of the monomeric diamines,… More >

  • Open Access

    ARTICLE

    Thiol-yne Reaction of Alkyne-d erivatized Fatty Acids: Thiol-Reactive Linear Polyurethane

    Rodolfo J. González-Paz, Gerard Lligadas*, Juan C. Ronda, Marina Galià, Virginia Cádiz

    Journal of Renewable Materials, Vol.1, No.3, pp. 187-194, 2013, DOI:10.7569/JRM.2013.634114

    Abstract A thiol-reactive linear polyurethane was synthesized from a vinyl-sulphide-containing diol and a commercial diisocyanate. The diol was obtained from 10-undecynol, an alkyne-derivatized fatty compound, using hydrothiolation as a key reaction step. 10-Undecynol was prepared by reduction of 10-undecinoic acid methyl ester, which was prepared by successive bromation, dehydrobromination of the corresponding alkenic fatty acid. Solution and surface polymer modifi cation with a fl uorescent thiol was successful. More >

  • Open Access

    ARTICLE

    From Fossil Resources to Renewable Resources: Synthesis, Structure, Properties and Comparison of Terephthalic Acid-2 ,5-Furandicarboxylic Acid-Diol Copolyesters

    Jiang Min, Lu Tingting, Zhang Qiang, Chen Ying, Zhou Guangyuan*

    Journal of Renewable Materials, Vol.3, No.2, pp. 120-141, 2015, DOI:10.7569/JRM.2014.634139

    Abstract Novel copolyesters were successfully synthesized from terephthalic acid (TPA), 2,5-furandicarboxylic acid (FDCA) and ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol and 1,8-octanediol via direct esterifi cation method by using tetrabutyl titanate (TBT) as catalyst. The copolyesters were characterized by nuclear magnetic resonance spectroscopy (1 H-NMR), gel permeation chromatography (GPC), X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and tensile tests. The results of GPC showed that all of the copolyesters had high molecular weight, with an average molecular weight (Mw) more than 1×104 g/mol. The results of 1 H-NMR showed that the copolyesters were random copolymers which compositions were well… More >

  • Open Access

    ARTICLE

    Investigating the Effects of the Driving Cycle and Penetration of Electric Vehicles on Technical and Environmental Characteristics of the Hybrid Energy System Considering Uncertainties

    Jiusong Chen1,*, Dejun Miao1, Yizong Dai1, Mojtaba Ghadamyari2,*

    Energy Engineering, Vol.119, No.5, pp. 1985-2003, 2022, DOI:10.32604/ee.2022.021142

    Abstract Electric vehicles (EVs) have received special consideration from modern society over the past several years. Although EVs are a fine example of environmentally friendly technology and have many advantages, they relatively increase the electricity demand upon a power grid as well. Therefore, their negative impact on busvoltage and line losses should be analyzed. In this study, the effect of EV loads and their penetration on bus voltage and line losses of an IEEE-33 bussystem has been examined via two scenarios. It is important to mention that the effect of EVs on the rate of air pollution, produced by fossil fuel… More >

  • Open Access

    ARTICLE

    Impact of Polymerization Protocol on Structure-Property Relationships of Entirely Lipid-Derived Poly(ester urethane)s

    Shegufta Shetranjiwalla, Shaojun Li, Laziz Bouzidi, Suresh S. Narine*

    Journal of Renewable Materials, Vol.5, No.5, pp. 333-344, 2017, DOI:10.7569/JRM.2017.634102

    Abstract The impact of polymerization protocol on phase structure and properties of entirely lipid-derived thermoplastic poly(ester urethane)s (TPEU)s was investigated. The TPEUs were synthesized from 1,7-heptamethylene diisocyanate, polyester diols and 1,9-nonanediol (ND) as chain extender. A two-stage polymerization method was used to prepare two TPEUs; one in which ND was added in the first stage of polymerization as part of the prepolymer and another in the second stage after the prepolymer was formed. Two very different morphologies exhibiting different degrees of phase separation were obtained, driven by the sequence of addition of the chain extender. The incorporation of the chain extender… More >

  • Open Access

    ARTICLE

    Synthesis and Reinforcement of Thermostable Polymers Using Renewable Resources

    Nicole Segura Salas1, Felipe Orozco Gutiérrez3, Luis Daniel Mora Murillo2, Yendry Corrales Ureña3, Shakira Johnson1, José Vega Baudrit3, Rodolfo Jesús González-Paz3*

    Journal of Renewable Materials, Vol.5, No.3-4, pp. 313-322, 2017, DOI:10.7569/JRM.2017.634122

    Abstract Vegetable oils are being used for the production of biodegradable polymers, opening new possibilities for the synthesis of greener materials that could compete in national markets with petroleum-based polymers. In this study, castor oil and a catalyst (cobalt[II] naphtenate as promotor and MEKP as initiator) from local stores and styrene in different ratios were used to produce thermostable polymers. The kinetics of the polymerization reaction was followed by infrared spectroscopy. A polymeric material was synthetized which presents good mechanical properties. Therefore, composites were produced using 1 wt% of microcellulose extracted from biomass waste as reinforcement or 1 wt% microsilica to… More >

  • Open Access

    ARTICLE

    Thermal-Mechanical Characterization of Polyurethane Rigid Foams: Effect of Modifying Bio-Polyol Content in Isocyanate Prepolymers

    Luis Daniel Mora-Murillo1, Felipe Orozco-Gutierrez2, José Vega-Baudrit2, Rodolfo Jesús González-Paz2*

    Journal of Renewable Materials, Vol.5, No.3-4, pp. 220-230, 2017, DOI:10.7569/JRM.2017.634112

    Abstract Nowadays, green polyurethane (PU) foams are mostly synthesized by replacing an amount of petrochemical polyol with biobased polyol. Here we report five different families of isocyanate prepolymer formulations that were prepared with biobased sources and the correlation between the structure of chains and the properties of the produced PU foam. Foam behavior in tension, torsion, compression, shape memory tests and physical properties were studied by dynamic mechanical thermal analysis (DMTA); interactions in the polymer chains were analyzed by Fourier transform infrared spectroscopy (FTIR); and thermal analysis was performed by thermogravimetry (TGA) and differential scanning calorimetry (DSC). The results showed that… More >

  • Open Access

    ARTICLE

    Mechanical and Thermal Properties of High-Density Rigid Polyurethane Foams from Renewable Resources

    M. Kirpluks1*, U. Cabulis1, A. Ivdre1, M. Kuranska2, M. Zieleniewska3, M. Auguscik3

    Journal of Renewable Materials, Vol.4, No.1, pp. 86-100, 2016, DOI:10.7569/JRM.2015.634132

    Abstract The most common sustainable solution for polyurethane (PU) materials is their production using renewable resources. Polyols derived from biomass and recycled polymers are the most promising way to do that. This study compares five different sustainable polyols as a possible raw material for production of highdensity rigid PU foams for automotive application. The goal of our study was to show that biobased polyols are a suitable replacement for polyols derived from petrochemical products. The influence of the chemical structure of polyols on the PU polymer matrix and foam properties was investigated. Two sources of PU raw material feedstock were studied:… More >

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