Jie Xu^1,3, Jiayao Yang¹, Peng Lin², Xiaohuan Liu^1,*, Jinjie Zhang¹, Shenyuan Fu^1,*, Yuxun Tang^2,*

Journal of Renewable Materials, Vol.7, No.12, pp. 1333-1346, 2019, DOI:10.32604/jrm.2019.07905

Abstract It is essential to design economic and efficient tougheners to prepare high-performance epoxy resin; however, this has remained a huge challenge. Herein, an eco-friendly, low-cost, and facile-fabricated bio-based hyperbranched toughener, carboxylic acid-functionalized tannic acid (CATA), was successfully prepared and applicated to the preparation of solvent-free epoxy resins. The mechanical performance, morphology, structural characterization, and thermal characterization of toughened epoxy resin system were studied. The toughened epoxy resin system with only 1.0wt% CATA reached the highest impact strength, 111% higher than the neat epoxy resin system. Notably, the tensile strength and elongation at break of toughened epoxy resin systems increased moderately… More >

Samsul Rizal¹, Fizree, H. M.², Chaturbhuj K. Saurabh³, Deepu A. Gopakumar², N. A. Sri Aprilia⁴, D. Hermawan⁵, A. Banerjee⁶, Fazita M. R. M², Haafiz M. K. M.², Abdul Khalil H. P. S.^2,*

Journal of Renewable Materials, Vol.7, No.12, pp. 1269-1278, 2019, DOI:10.32604/jrm.2019.07227

Abstract Oil palm ash (OPA) is an agro-industry waste and it has disposable problems. In the present study, an effort was made for value addition to OPA by incorporating it as a micro-filler in different concentration (0, 10, 20, 30, 40, and 50%) and sizes (100, 200, and 300 mesh size particles) in the epoxy matrix. Prepared micro OPA was having a crystallinity index of 65.4%, high inorganic elements, and smooth surface morphology. Fabricated composites had higher void content as compared to neat epoxy matrix. Mechanical properties of fabricated composites had a maximum value at 30% loading of 300 mesh-size filler… More >

Luobin Wang, Feng Xu^*, Xiaofang Hu, Hongyan Qu, Hong Miao, Zhong Zhang

The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.2, pp. 55-56, 2011, DOI:10.3970/icces.2011.018.055

Abstract Recent studies have indicated that mechanical performance of the short fiber-reinforced polymers composites not only depends on matrix type, fiber type, fiber weight fraction, fiber orientation, fiber dispersion etc. but fiber-matrix interface and matrix morphology are also of paramount importance. Many scholars have studied on effects of matrix and interface modification on the mechanical behavior of short carbon fiber reinforced epoxy composite. However, there is little work focused on the in situ observation of fracture process of fiber/epoxy composites. And it is difficult to know about crack and crack propagation in the sample without direct observations of fiber-matrix interface when… More >

L.Y. Wang, W. B. Song Z.D. Wang

The International Conference on Computational & Experimental Engineering and Sciences, Vol.17, No.1, pp. 13-14, 2011, DOI:10.3970/icces.2011.017.013

Abstract Shape memory epoxies and their composites have great potential applications in future deployable space structures industry. In this study six types of shape memory epoxies with different shape transition temperatures were synthesized by varying the curing agents and their contents. Thermal frozen/recovery test, DSC and DMA were performed to investigate their shape memory behaviors and thermomechanical properties. Further discussions about the testing results were presented with consideration of the microstructure. More >

M.V.Hosur¹, M. M. Islam, S. Jeelani

The International Conference on Computational & Experimental Engineering and Sciences, Vol.6, No.1, pp. 81-90, 2008, DOI:10.3970/icces.2008.006.081

Abstract In this paper, low-velocity impact response of braided composites is presented. Three types of braided fabrics were used. They were:$\pm$45, 0/$\pm$45, and 0/$\pm$60. Laminates with 7 layers of$\pm$45 and 4 layers of 0/$\pm$45, and 0/$\pm$60 were fabricated by vacuum assisted resin infusion molding process to get an average thickness ranging from 2.25 to 2.4 mm. Samples of size 10$\times$ 10 cm were then cut from the panels and impacted at 10, 20 and 30 J. Impact parameters like peak load and absorbed energy were calculated and normalized for thickness. All the samples were then subjected to ultrasonic c-scan testing to… More >

M.V. Hosur¹, F.H. Chowdhury¹, S. Jeelani¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.2, No.4, pp. 119-124, 2007, DOI:10.3970/icces.2007.002.119

Abstract In the present study, Nanomer® I-28E, organically modified montmorillonite nanoclay supplied by Nanocor Inc., was used to modify SC-15, a toughened epoxy system using sonication route. Different weight percentage ranging from 1-3% of nanoclay was used. The modified epoxy was then used to fabricate 15-layer plain weave carbon/epoxy composite laminates using vacuum assisted resin transfer molding (VARTM) method. Samples of size 100 x 100 mm were cut from the laminates and were subjected to low-velocity impact loading using an instrumented drop-weight system (Dynatup Model 8210) at three different energy levels of 10, 20 and 30J. Transient response of the samples… More >

Wajdi Zouari^1,*, Mustapha Assarar¹, Abderrazak Chilali², Rezak Ayad¹, Hocine Kebir³

Journal of Renewable Materials, Vol.7, No.9, pp. 839-853, 2019, DOI:10.32604/jrm.2019.06773

Abstract This contribution deals with the development of a three-node triangular plane finite element to analyze the transient hygroscopic behavior of 2/2 twill flax fabric-reinforced epoxy composite. Several plates of this material were fabricated using the vacuum infusion process and composite specimens were then cut and aged in tap water at room temperature until saturation. To simplify, a plane modelling of water diffusion in the aged specimens is adopted and Fick’s model is used to describe the water diffusion kinetics. To highlight the heterogeneity of the flax-epoxy samples, the twill flax fabrics waviness is modelled with a sinusoidal undulation. In particular,… More >

Puyou Jia¹, Fei Song¹, Qiaoguang Li^2,*, Haoyu Xia³, Mei Li^1,*, Xugang Shu², Yonghong Zhou¹

Journal of Renewable Materials, Vol.7, No.7, pp. 601-619, 2019, DOI:10.32604/jrm.2019.07011

Abstract Polymers from renewable resources are receiving tremendous attention due to the increasing concerns on the depletion of fossil oils and deteriorated environments. Cardanol, as an abundant and renewable chemical raw material, has been widely used for the production of renewable polymer materials via converting into various of chemical monomers with active functional groups. This comprehensive review deals with various aspects of cardanol as a starting material the preparing various polymer and polymer composites such as benzoxazine resins, phenolic resin, polyurethanes, epoxy resin, vinyl ester polymers, polyamide and cyanate ester resins. The assessment of the future prospects for the use of… More >

C. M. Meenakshi, A. Krishnamoorthy^*

Journal of Renewable Materials, Vol.7, No.2, pp. 153-169, 2019, DOI:10.32604/jrm.2019.00046

Abstract Natural fiber-reinforced hybrid composites can be a better replacement for plastic composites since these plastic composites pose a serious threat to the environment. The aim of this study is to analyze the effect of surface modification of the natural fibers on the mechanical, thermal, hygrothermal, and water absorption behaviors of flax, sisal, and glass fiber-reinforced epoxy hybrid composites. The mechanical properties of alkaline treated sisal and flax fibers were found to increase considerably.Tensile, flexural and impact strength of glass/flax-fiber-reinforced hybrid samples improved by 58%, 36%, and 51%, respectively, after surface alkaline treatment. In addition, the hygrothermal analysis and water absorption… More >

Mehul Barde^1,2, Yusuf Celikbag³, Brian Via³, Sushil Adhikari⁴, Maria L. Auad^1,2,*

Journal of Renewable Materials, Vol.6, No.7, pp. 724-736, 2018, DOI:10.32604/JRM.2018.00116

Abstract Bio-based phenol-formaldehyde polymer (BioNovolac) was developed by reacting molar excess of bio-oil/phenol with formaldehyde in acidic medium. Glycidyl 3,5-diglycidoxybenzoate (GDGB), was prepared by direct glycidylation of α-resorcylic acid (RA), a naturally occurring phenolic monomer. GDGB was crosslinked in the presence of BioNovolac by anionic polymerization. Fourier transform infrared spectroscopy (FTIR) confirmed the formation of semi-interpenetrating polymer networks. The glass transition temperature and moduli of bio-based crosslinked systems were observed to increase with increasing GDGB content. Active chain density and mass retention measured by dynamic mechanical analysis (DMA) and Soxhlet extraction, respectively, indicated a high crosslink density of the cured networks.… More >