Yang Liu¹, Jianjun Xie^1,*, Peng Hao¹, Ying Shi¹, Yonggen Xu^2,3, Xiaoqing Ding^2,3

Journal of Renewable Materials, Vol.9, No.2, pp. 237-253, 2021, DOI:10.32604/jrm.2021.012228 - 15 December 2020

Abstract Foam glass is a new green material to make use of waste glass and is popular for its energy-saving and light weight features. The problems in the current study of foam glass is that its properties require improvement to match the growing demands of application specific standards. Properties of foam glass is related to its porous structure, which is affected by various factors. The influence of raw material component, foaming agents and sintering system on the porous structure and properties of foamed glass is studied. Density decreases with the decrease of quartz and barite content.… More >

Fangzhou Wang^a,* , Gennifer A. Riley^b, Munonyedi Egbo^c, Melanie M. Derby^b, Gisuk Hwang^c, Xianglin Li^a,†

Frontiers in Heat and Mass Transfer, Vol.15, pp. 1-8, 2020, DOI:10.5098/hmt.15.1

Abstract This study conducts pore-scale simulations and experiments to estimate the permeability of two different types of porous materials: metal foams and sintered copper particles with porosities of approximately 0.9 and 0.4, respectively. The integration of micro X-ray computed tomography with pore-scale computational fluid dynamics simulations develops a unique tool to capture the pore-scale geometry of porous media and accurately predict non-isotropic permeability of porous media. The pore-scale simulation not only results in improved prediction accuracy but also has the capability to capture non-isotropic properties of heterogeneous materials, which is a huge challenge for empirical correlations,… More >

Jinxing Li^1,#, Jingjing Liao^1,#, Jun Zhang¹, Xiaojian Zhou^1,2,*, Hisham Essawy³, Guanben Du^1,2

Journal of Renewable Materials, Vol.8, No.12, pp. 1607-1616, 2020, DOI:10.32604/jrm.2020.013976 - 12 November 2020

Abstract In this study, pre-concentrated bark, furfuryl alcohol and other biomass raw materials were used to prepare foaming materials by high-speed mechanical stirring without using a foaming agent. We investigated the effect of the postadded water amount on the properties of foaming materials. In particular, we determined basic physical properties of these materials, including the limiting oxygen index (LOI), porosity, thermal conductivity, thermogravimetric analysis, pore size distribution, and microstructure. The results of scanning electron microscopy (SEM) indicated that the pore size distribution was uniform and the pore size increased with increasing water volume. Thermogravimetric analysis (TG/… More >

Ilze Beverte^1,*, 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 >

Ajay Veludurthi¹, Venkateshwarlu Bolleddu^2,*

Energy Engineering, Vol.117, No.4, pp. 237-248, 2020, DOI:10.32604/EE.2020.011304 - 31 July 2020

Abstract Mechanical characteristics of small wind turbine blades of National Advisory Committee for Aeronautics (NACA) 63-415 series with different Univinyl (UV) foam alignments have been evaluated experimentally using Universal Testing Machine and numerically using Finite Element Analysis (FEA) software ANSYS. The wind turbine blade models considered are selected from the NACA 63415 series to give a power output of 1 kW. The blades in this study are made like a sandwich beam structure. The outermost portion of the blade is made of glass fiber reinforced plastics with epoxy resin as composite and Uni-vinyl foam alignments are… More >

Dzun Noraini Jimat^*, Sharifah Shahira Syed Putra, Parveen Jamal, Wan Mohd Fazli Wan Nawawi, Mohammed Saedi Jami

Journal of Renewable Materials, Vol.8, No.7, pp. 739-757, 2020, DOI:10.32604/jrm.2020.010357 - 01 June 2020

Abstract Increasing usage of foams in various industry sectors had causing serious disposal problems once it reaches the end of its life-cycle. Herein, PVA-MFC foam was prepared by freeze-drying using polyvinyl alcohol (PVA) and microfibrillated cellulose (MFC) as a reinforced material from sugarcane bagasse (SCB). In this study, the PVA-MFC foam was chemically silylated with Y-methacryloxypropyltrimethoxysilane (MPS) and tetraethoxysilane (TEOS). The wetting ability and mechanical strength of the silylated _2,20PVA-MFC foam was greatly enhanced compared with unmodified _2,20PVA-MFC foam. The silane chemicals (MPS and TEOS) had been confirmed grafted on _2,20PVA-MFC foam due to the presence of Si-C… More >

Fei Song^1,2, Puyou Jia^1,*, Caiying Bo¹, Xiaoli Ren¹, Lihong Hu¹, Yonghong Zhou^1,*

Journal of Renewable Materials, Vol.8, No.5, pp. 535-547, 2020, DOI:10.32604/jrm.2020.09304 - 29 April 2020

Abstract In this study, we prepared a series of tung oil phenolic foams (TPF) by a one-pot method. The FT-IR and 1 H NMR spectra confirm the successful FriedelCrafts grafting of phenol to the long-chain alkyl group in tung oil. Modified TPFs exhibit enhanced mechanical properties, including compressive and flexural strengths of up to 0.278 ± 0.036 MPa and 0.450 ± 0.017 MPa, respectively, which represent increases of 68.75% and 86.72% over those of pure phenolic foam (PF). SEM spectra reveal the TPF microstructure to have uniform hexagonal cell morphology, narrower cell size distribution, and smaller More >

Rui Hou¹, Zhihuang Zhang¹, Guangzhao Zhang¹, Donglin Tang^1,2,3,*

Journal of Renewable Materials, Vol.8, No.4, pp. 397-403, 2020, DOI:10.32604/jrm.2020.08912 - 24 April 2020

Abstract It has been proved that introducing isocyanurate into polymer chains could improve the flame retardancy of polymers. We describe in this work the synthesis and the thermal property study of three thermoplastic polyisocyanurates, which are polyisocyanuratoamide (PICA-6), polyisocyanurato(ester amide) (PICEA-6) and polyisocyanurato(urea ester) (PICUE-6). These polymers show similar and improved thermal stability with the existence of isocyanurate rings. PICA-6 is more crystalizable than the rest two and the melting temperature is found to be around 240°C but it still crystalizes slowly. For PICEA-6 and PICUE-6, only glass transition can be observed on the DSC traces. More >

Nadezhda Petkova^1,*, Radka Arabadzhieva¹, Dragomir Vassilev², Gergana Gencheva¹, Yulian Tumbarski³, Tsveteslava Ignatova-Ivanova⁴, Sevginar Ibryamova⁴, Mina Todorova¹, Milena Koleva², Panteley Denev¹

Journal of Renewable Materials, Vol.8, No.4, pp. 365-381, 2020, DOI:10.32604/jrm.2020.09292 - 24 April 2020

Abstract Microwave-assisted irradiation was performed for esterification of chicory inulin with high degree of polymerization with acetic anhydride without a solvent only with a catalyst. The resulting esters were characterized by melting point, hydrophilic-lipophilic balance, thin-layer chromatography, ultraviolet spectroscopy, Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR) spectroscopy. Inulin acetate demonstrated a high degree of acetylation (2.5–3.0) and presented a white, water-insoluble substance with bitter taste. The FTIR and NMR spectra confirmed esterification and demonstrated the incorporation of hydrophobic residue to the water soluble inulin backbone. Swelling capacity, water holding, oil-holding capacities, the foamability,… More >

Ajay Veludurthi¹, Venkateshwarlu Bolleddu^2,*

Energy Engineering, Vol.117, No.2, pp. 49-61, 2020, DOI:10.32604/EE.2020.010666 - 23 April 2020

Abstract This work focused on modal and harmonic analysis of small wind turbine blades taken from the NACA 63415 series. The sandwich structure type composite blade is fabricated from GFRP and epoxy with Uni-vinyl hard foams of different alignments as stiffeners. In this work, the modal and harmonic analysis of different varieties of blades like solid, hallow and rectangular alignment blades is carried out by the finite element method using ANSYS 18.1 software. From Finite Element Analysis, the natural frequencies, amplitudes and mode shapes are obtained. Based on the working principle of wind turbine blades, the More >