R. J. Johnson^∗, R. Pitchumani^†

Frontiers in Heat and Mass Transfer, Vol.1, No.1, pp. 1-9, 2010, DOI:10.5098/hmt.v1.1.3007

Abstract Much research is currently being performed with carbon nanotube additives to neat resin systems to enhance properties such as thermal and electrical conductivity, strength, modulus and damping. Fabrication of parts based on carbon nanotube filled resin systems requires information on their cure kinetics and rheology, which has been relatively less studied so far. This work presents an extensive experimental study that systematically characterizes the cure kinetics and viscosity as a function of degree of cure and temperature of EPON 815C/EPICURE 3274 epoxy resin system laden with carbon nanotubes. Studies are conducted to determine the effects of the carbon nanotube loading… More >

Qianyu Zhang^1,2,#, Shi Chen^1,2,#, Long Cao^1,2, Hong Lei³, Antonio Pizzi⁴, Xuedong Xi^1,2,*, Guanben Du^1,2

Journal of Renewable Materials, Vol.12, No.2, pp. 235-244, 2024, DOI:10.32604/jrm.2023.029537

Abstract Using non-toxic, low-volatile glyoxal to completely replace formaldehyde for preparing urea-glyoxal (UG) resin adhesive is a hot research topic that could be of great interest for the wood industry. However, urea-glyoxal (UG) resins prepared by just using glyoxal instead of formaldehyde usually yields a lower degree of polymerization. This results in a poorer bonding performance and water resistance of UG resins. A good solution is to pre-react urea to preform polyurea molecules presenting already a certain degree of polymerization, and then to condense these with glyoxal to obtain a novel UG resin. Therefore, in this present work, the urea was… More > Graphic Abstract

Bengang Zhang^1,*, Antonio Pizzi^2,*, Mathieu Petrissans¹, Anelie Petrissans¹, Baptiste Colin¹

Journal of Renewable Materials, Vol.11, No.11, pp. 3867-3889, 2023, DOI:10.32604/jrm.2023.028888

Abstract Melamine-dialdehyde starch resins used for wood surface finishes have been developed. The reaction of melamine with dialdehyde starch has been shown to occur by FTIR and MALDI ToF spectrometry, with several oligomer species due to the reaction of the two materials being identified, and the resin thermal stability was studied by thermogravimetric analysis. The resins were prepared by two different procedures when it was realized that dialdehyde starch is sensitive to too high a temperature for prolonged times. The melamine-dialdehyde starch resins were applied on particleboard supports as a direct liquid surface finish and a resin-impregnated paper. The surface finishes… More >

Chunhua Liu¹, Dongfang Zou¹, Qinqin Huang¹, Shang Li², Xia Zheng¹, Xingong Li^1,*

Journal of Renewable Materials, Vol.11, No.10, pp. 3613-3624, 2023, DOI:10.32604/jrm.2023.028111

Abstract The residual resources of ramie fiber-based textile products were used as raw materials. Ramie fiber felt (RF) was modified by NaClO₂ aqueous solution and then impregnated with water-based epoxy resin (WER). RF/WER transparent composite materials were prepared by lamination hot pressing process. The composite materials’color difference, transmittance, haze, density, water absorption, and mechanical properties were determined to assess the effects of NaClO₂ treatment and the number of ramie fiber layers on the properties of the prepared composites. The results showed significantly improved optical and mechanical properties of the RF/WER transparent composites after NaClO₂ treatment. With the increase of ramie fiber… More > Graphic Abstract

Yuhui Huang¹, Zhiyuan Yin^1,2, Ming Liu¹, Meng Li¹, Yingfeng Zuo¹, Yan Qing¹, Yiqiang Wu^1,*

Journal of Renewable Materials, Vol.11, No.9, pp. 3417-3431, 2023, DOI:10.32604/jrm.2023.028511

Abstract The poor bonding performance between aqueous adhesives represented by melamine-urea formaldehyde (MUF) resins and reed straw hinders their applications in the field of non-wood-based panels. Multi-hydroxyl polymers are highly reactive and are often used as crosslinkers. This study fabricated a resin with a strengthened cross-linked structure by combining a multi-hydroxyl polymer and MUF resin prepolymer. The reed particleboard was prepared by using this resin as an adhesive and reed stalk as the matrix. The results show that neighboring molecules combined to form C–O–C bonds that strengthened the cross-linked structure of the resin. In addition, the viscosity of the resin was… More >

Guobing Xiong¹, Lu Hong², Zehui Ju³, Xiaoning Lu^3,*, Juwan Jin^3,*

Journal of Renewable Materials, Vol.11, No.9, pp. 3447-3461, 2023, DOI:10.32604/jrm.2023.027430

Abstract The study characterized the curing behaviors of phenol formaldehyde (PF) resin under different vacuum degrees and explored the properties of 9-ply plywood panels hot-pressed under both vacuum and atmospheric conditions. The changes in core temperature and moisture content of the plywood mats during hot pressing were investigated as well. It was found that the gel times and gel temperatures of PF resin decreased with the increase of vacuum degree using a self-made device. FTIR spectra indicated the degree of polycondensation of hydroxymethyl gradually increased with the increase in temperature. It was also observed that a higher degree of vacuum led… More >

Marwah Subhi Attallah, Reem Alaa Mohammed^*, Ruaa Haitham Abdel-Rahim

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.10, pp. 2449-2469, 2023, DOI:10.32604/fdmp.2023.027750

Abstract This study aims to evaluate the erosion behavior and the hardness of hybrid composites made of varying amounts of coconut shells, walnut shells, and carbon fibers dispersed in a polyester matrix. MINITAB (L16) Taguchi experiments were used to determine the optimal combination of parameters. In particular, an erosion device consisting of a motor with a constant flow rate of 45 L/min, a pump with a diameter of 40 mm, a nozzle with a diameter of 5 mm, and a tank made of “perspex glass” 55 cm long, 30 cm tall, and 25 cm wide was used. The tests were conducted by varying the sample-to-nozzle distance, the… More > Graphic Abstract

Jinlong Shang^*

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.9, pp. 2315-2328, 2023, DOI:10.32604/fdmp.2023.026742

Abstract In this study, the durability of a new polymer carbon fiber-reinforced epoxy resin used to produce composite material in the aerospace field is investigated through analysis of the corrosion phenomena occurring at the microscopic scale, and the related infrared spectra and thermal properties. It is found that light and heat can contribute to the aging process. In particular, the longitudinal tensile strength displays a non-monotonic trend, i.e., it first increases and then decreases over time. By contrast, the longitudinal compressive and inter-laminar shear strengths do not show significant changes. It is also shown that the inter-laminar shear strength of carbon… More >

Nurul Anis Athirah Ab Aziz^*, Chin Wei Lai^*, Boon Hoong Ong

Journal of Renewable Materials, Vol.11, No.6, pp. 2745-2770, 2023, DOI:10.32604/jrm.2023.025899

Abstract Nowadays, corrosion is not only undesirable, but it also has a significant influence on the industrial sectors and technical innovations that have demand for metals. The global economic damage is expected to reach $2.5 trillion, equivalent to more than 3.4% of the world’s GDP in 2013. It is linked with significant financial harm, manufacturing pollution, and safety issues. An electrochemical process primarily induces metal corrosion at the metalelectrolyte interface region, caused by steel oxidation and the reduction of oxygen, protons, and water. Therefore, organic and epoxy coatings can be applied as protective coatings. Additionally, it can prevent metal corrosion in… More > Graphic Abstract

Li Xiao^1,2, Xu Yang^1,2,*, Guozhi Zhang^1,2, Lin Cheng^1,2, Yi Jiang^1,2, Chuanxian Luo^1,2, Jing Zhang^1,2

Energy Engineering, Vol.120, No.5, pp. 1239-1252, 2023, DOI:10.32604/ee.2023.025530

Abstract In view of the effective perception demand of PD (Partial Discharge) insulation defect of in-service GIS (Gas Insulated Switchgear), the external UHF (Ultra High Frequency, 0.3−3 GHz) sensing technology for GIS PD insulation defect from resin hole is studied in this paper. Firstly, rectangular waveguide theory is used to analyze the electromagnetic wave propagation characteristics from rectangular resin hole in GIS disc insulator. It is found that the energy of leaked electromagnetic wave mainly concentrates in the frequency band above 1 GHz. Then based on this frequency band characteristics, a cavity-backed bowtie sensor for GIS PD external detection is designed… More >