Ahmed Mustaffa Saleem, Abdullah A. Badr, Bahjat Hassan Alyas, Omar Rafae Alomar^*

Frontiers in Heat and Mass Transfer, Vol.22, No.4, pp. 1231-1244, 2024, DOI:10.32604/fhmt.2024.053770 - 30 August 2024

Abstract This study numerically involves the performance of thermal insulation of different types of composite walls and roofs to demonstrate the best model that can be used for energy-efficient building construction in Iraq. The mathematical model is solved by building its code using the Transmission Matrix Method in MATLAB software. The weather data of 21st July 2022 in Baghdad City/Iraq is selected as a test day. The wall types are selected: the first type consists of cement mortar, brick, and gypsum, the second type consists of cement mortar, brick, gypsum, and plaster and the third type… More >

Awanda Wira Anggini^1,2, Rita Kartika Sari², Efri Mardawati^3,4, Tati Karliati⁵, Apri Heri Iswanto⁶, Muhammad Adly Rahandi Lubis^1,4,*

Journal of Renewable Materials, Vol.12, No.7, pp. 1165-1186, 2024, DOI:10.32604/jrm.2024.051854 - 21 August 2024

Abstract More than a century after its initial synthesis, urea-formaldehyde (UF) resins still have dominant applications as adhesives, paints, and coatings. However, formaldehyde in this industry produces formaldehyde emissions that are dangerous to health. Scientists have spent the last decade replacing formaldehyde and phenol with environmentally friendly substances such as glyoxal and tannin to create bio-based adhesives. This review covers recent advances in synthesizing glyoxal tannin-based resins, especially those made from sustainable raw material substitutes and changes made to synthetic processes to improve mechanical properties. The efficacy of using tannin-glyoxal adhesives in producing wood-based composites has… More > Graphic Abstract

Mohammed Mohammed^1,2,*, Jawad K. Oleiwi³, Aeshah M. Mohammed⁴, Anwar Ja’afar Mohamad Jawad⁵, Azlin F. Osman^1,2, Tijjani Adam⁶, Bashir O. Betar⁷, Subash C. B. Gopinath^2,8,9

Journal of Renewable Materials, Vol.12, No.7, pp. 1237-1290, 2024, DOI:10.32604/jrm.2024.051201 - 21 August 2024

Abstract Natural fibre (NFR) reinforced functional polymer composites are quickly becoming an indispensable sustainable material in the transportation industry because of their lightweight, lower cost in manufacture, and adaptability to a wide variety of goods. However, the major difficulties of using these fibres are their existing poor dimensional stability and the extreme hydrophilicity. In assessing the mechanical properties (MP) of composites, the interfacial bonding (IB) happening between the NFR and the polymer matrix (PM) plays an incredibly significant role. When compared to NFR/synthetic fibre hybrid composites, hybrid composites (HC) made up of two separate NFR are… More > Graphic Abstract

Aleksandra Jeżo^*

Journal of Renewable Materials, Vol.12, No.6, pp. 1029-1042, 2024, DOI:10.32604/jrm.2024.051330 - 02 August 2024

Abstract Bark extracts are sustainable sources of biopolymers and hold great promise for replacing fossil fuel-based polymers, for example, in wood-based composites. In addition to primary and secondary metabolites, tree bark also contains suberin, which plays a major role in protecting the tree from environmental conditions. Suberin is a natural aliphatic-aromatic cross-linked polyester present in the cell walls of both normal and damaged external tissues, the main component of which are long-chain aliphatic acids. Its main role as a plant ingredient is to protect against microbiological factors and water loss. One of the most important suberin More >

Haoping Yao¹, Xinyu Zhong², Chunxia He^1,*

Journal of Renewable Materials, Vol.12, No.5, pp. 993-1006, 2024, DOI:10.32604/jrm.2024.047758 - 17 July 2024

Abstract To make full use of plant shell fibers (rice husk, walnut shell, chestnut shell), three kinds of wood-plastic composites of plant shell fibers and polyvinyl chloride (PVC) were prepared. X-ray diffraction analysis was carried out on three kinds of plant shell fibers to test their crystallinity. The aging process of the composites was conducted under 2 different conditions. One was artificial seawater immersion and xenon lamp irradiation, and the other one was deionized water spray and xenon lamp irradiation. The mechanical properties (tensile strength, flexural strength, impact strength), changes in color, water absorption, Fourier transform… More >

İbrahim Yavuz^1,*, Ercan Şimşir¹, Kenan Budak²

Journal of Polymer Materials, Vol.41, No.1, pp. 1-14, 2024, DOI:10.32604/jpm.2024.052279 - 21 June 2024

Abstract In this study, natural fiber reinforced polymer foam core layered composites were produced for the automotive industry. Sheep wool was used as natural fiber. Polymer foam with a single layer XPS foam structure was used as the core material. XPS foams and fibers are bonded to the upper and lower sides of the foams with the help of resin. Samples were produced with one and two layers on both sides, with a total of two and four layers. Production was carried out using the vacuum bagging method using the manual laying method. After the production More >

Hantao Huang, Zhifang Zhang^*, Zhenhua Wu, Yao Liu

Structural Durability & Health Monitoring, Vol.18, No.4, pp. 409-423, 2024, DOI:10.32604/sdhm.2024.048597 - 05 June 2024

Abstract In this paper, recycled carbon fiber reinforced polymer (CFRP) mixture (CFRP-M, including recycled carbon fiber and powder) and refined recycled CFRP fiber (CFRP-F, mostly recycled carbon fiber) were added to cement to study the influence of addition on the flexural strength, compressive strength, and fluidity of cement-based materials. The recycled CFRP were prepared by mechanically processing the prepreg scraps generated during the manufacture of CFRP products. For comparison, commercial carbon fiber powder was also added in cement and the performance was compared to that of addition of recycled CFRP. The hydration products and strengthening mechanism… More >

Chengkan Xu^1,2,4, Xiaofei Wang³, Yixuan Li², Guannan Wang^2,*, He Zhang^2,4,*

CMES-Computer Modeling in Engineering & Sciences, Vol.140, No.1, pp. 957-974, 2024, DOI:10.32604/cmes.2024.047327 - 16 April 2024

Abstract Structural damage in heterogeneous materials typically originates from microstructures where stress concentration occurs. Therefore, evaluating the magnitude and location of localized stress distributions within microstructures under external loading is crucial. Repeating unit cells (RUCs) are commonly used to represent microstructural details and homogenize the effective response of composites. This work develops a machine learning-based micromechanics tool to accurately predict the stress distributions of extracted RUCs. The locally exact homogenization theory efficiently generates the microstructural stresses of RUCs with a wide range of parameters, including volume fraction, fiber/matrix property ratio, fiber shapes, and loading direction. Subsequently, More > Graphic Abstract

Joseph O. Dirisu^1,*, Imhade P. Okokpujie^2,3,*, Olufunmilayo O. Joseph¹, Sunday O. Oyedepo¹, Oluwasegun Falodun⁴, Lagouge K. Tartibu³, Firdaussi D. Shehu¹

Journal of Renewable Materials, Vol.12, No.3, pp. 485-511, 2024, DOI:10.32604/jrm.2024.045188 - 11 April 2024

Abstract Research into converting waste into viable eco-friendly products has gained global concern. Using natural fibres and pulverized metallic waste becomes necessary to reduce noxious environmental emissions due to indiscriminately occupying the land. This study reviews the literature in the broad area of green composites in search of materials that can be used in automotive brake pads. Materials made by biocomposite, rather than fossil fuels, will be favoured. A database containing the tribo-mechanical performance of numerous potential components for the future green composite was established using the technical details of bio-polymers and natural reinforcements. The development… More > Graphic Abstract

Rabar H. Faraj^1,*, Hemn Unis Ahmed^2,3, Hardi Saadullah Fathullah⁴, Alan Saeed Abdulrahman², Farid Abed⁵

CMES-Computer Modeling in Engineering & Sciences, Vol.138, No.3, pp. 2925-2954, 2024, DOI:10.32604/cmes.2023.029392 - 15 December 2023

Abstract Plain concrete is strong in compression but brittle in tension, having a low tensile strain capacity that can significantly degrade the long-term performance of concrete structures, even when steel reinforcing is present. In order to address these challenges, short polymer fibers are randomly dispersed in a cement-based matrix to form a highly ductile engineered cementitious composite (ECC). This material exhibits high ductility under tensile forces, with its tensile strain being several hundred times greater than conventional concrete. Since concrete is inherently weak in tension, the tensile strain capacity (TSC) has become one of the most… More >