Ahmad Safwan¹, Mohammad Jawaid^1*, Mohamed T. H. Sultan^1,2, Azman Hassan³

Journal of Renewable Materials, Vol.6, No.5, pp. 529-535, 2018, DOI:10.7569/JRM.2018.634103

Abstract The application of natural fibers as reinforcement in composite material has increased due to environmental concerns, low cost, degradability and health concerns. The purpose of this study is to identify the best type of bamboo fibers to be used as reinforcement for kenaf (K)/bamboo hybrid composite. There were three types of bamboo fibers evaluated in this study which include bamboo mat (B), bamboo fabric (BF) and bamboo powder (BP). Chemical composition of B, BF, BP and K fibers were analyzed in this study. The effect of different types of bamboo fibers on tensile, impact, and More >

Kunal Wazarkar, Anagha Sabnis*

Journal of Renewable Materials, Vol.6, No.5, pp. 517-528, 2018, DOI:10.7569/JRM.2017.634181

Abstract This research work discloses the preparation of polyurethane coatings from cardanol modified using thiolene chemistry, wherein unsaturated long alkyl chain of cardanol was successfully utilized via thiol-ene click reaction to synthesize polyol. For this purpose, cardanol and thioglycerol was reacted in the presence of Irgacure 184 (photoinitiator) and 1,8-Diazabicyclo[5.4.0]undec-7-ene (catalyst) and exposed to UV light for 12 h at 80 °C. One mole of thioglycerol was successfully added across the double bond of fatty chain of cardanol and confirmed by chemical and spectroscopic analysis. Further, the polyol thus prepared was cured with various polyisocyanates, viz., More >

Maha L. Shrestha^{1, 2,*}, Mihail Ionescu¹, Xianmei Wan¹, Zoran S. Petrović¹

Journal of Renewable Materials, Vol.6, No.5, pp. 504-516, 2018, DOI:10.7569/JRM.2017.634187

Abstract Biobased aromatic-aliphatic polyols were previously synthesized from a thermal thiol-ene reaction of propoxylated cardanol with 2-mercaptoethanol (ME) in the presence of azobisisobutyronitrile (AIBN) as a radical initiator. Cardanol used for this purpose was obtained as a dark-brown liquid (Gardner Color Reference ∼18). The photochemical thiol-ene reaction can also be used to prepare aromatic-aliphatic polyols by employing cardanol. Via the photochemical thiol-ene reaction, 2-mercaptoethanol was added successfully to C=C double bond of cardanol, suggesting that phenolic group may not play an inhibitory role in the radical thiol-ene reaction. However, we preferred to alkoxylate the phenolic hydroxyl More >

Andrea Dorigato^1,*, Martino Negri², Alessandro Pegoretti^1,*

Journal of Renewable Materials, Vol.6, No.5, pp. 493-503, 2018, DOI:10.7569/JRM.2017.634177

Abstract Novel fully biodegradable thermoplastic composite laminates reinforced with ultrathin wood laminae were prepared through a hot-pressing process by using two different thermoplastic starch (TPS) matrices. The microstructure and physical properties of the resulting unidirectional and bidirectional laminates were studied. The investigated materials presented a complex microstructure, in which the porosity of the wood laminae was almost entirely occluded by the polymer matrix. The mechanical behavior of the laminates was strongly affected by the obtained microstructure, and matrix penetration in wood pores led to biodegradable composites with elastic modulus and tensile strength higher than those of More >

A. Atiqah¹, M. Jawaid^1,*, S. M. Sapuan^1,2, M. R. Ishak³

Journal of Renewable Materials, Vol.6, No.5, pp. 477-492, 2018, DOI:10.7569/JRM.2017.634188

Abstract The aim of the present study was to develop sugar palm fiber (SPF) reinforced thermoplastic polyurethane (TPU) composites and to investigate the effects of fiber surface modification by 2% silane treatment and fiber loading (0, 10, 20, 30, 40 and 50 wt%) on the mechanical and thermal properties of the obtained composites. Surface treatment was employed to improve the fiber-matrix interface, which was expected to boost the mechanical strength of the composites, in terms of tensile, flexural and impact properties. Thermal properties were also investigated by thermal gravimetric analysis (TGA) and dynamic mechanical analysis (DMA)… More >

Min Fan^1,2,3*, Qiaoling Hu⁴

Journal of Renewable Materials, Vol.6, No.5, pp. 457-463, 2018, DOI:10.7569/JRM.2017.634178

Abstract The absorption behavior of chitosan in alkaline solution by freeze-blasting was studied. The influence of alkaline type, concentration, and small molecules was investigated, as well as the different roles of LiOH and NaOH in the absorption. Chitosan reached its maximum absorption rate when LiOH concentration was 4.8 wt% and NaOH 4.0 wt%, respectively. Chitosan showed better absorption capacity in LiOH solution. Urea could improve the absorption when its concentration was more than or equal to 4.0 wt%, and the improvement was greater in NaOH solution. Thiourea showed no obvious effect in LiOH solution, but showed More >

Haiyang Zhang^1,*, Qian He¹, Xiaoning Lu¹, A. Pizzi^2,3, Changtong Mei¹, Xianxu Zhan⁴

Journal of Renewable Materials, Vol.6, No.5, pp. 450-456, 2018, DOI:10.7569/JRM.2017.634180

Abstract Double cantilever beam tests were used to measure the energy release rates of linear vibrational welded moso bamboo joints. The influence of the length of the preserved cracks, the different combinations of the inner and outer bamboo surfaces and the moisture content is studied herein. The experimental compliance method, which is based on linear elastic fracture mechanics and has been shown to be an ideal method, was used to analyze data with the power equation. The results show that the preserved initial crack length does not have a significant effect on the final measured energy More >

Kunal Wazarkar, Anagha Sabnis*

Journal of Renewable Materials, Vol.6, No.4, pp. 438-449, 2018, DOI:10.7569/JRM.2017.634159

Abstract The research work presented in this article deals with the synthesis of cardanol-based polyol and its curing with hexabutoxymethyl melamine (HBMM) for application in coatings. Cardanol-based polyol was prepared via thiol-ene click reaction using thioglycerol. Unsaturation present in the long chain of cardanol was successfully utilized to synthesize polyol via thiol-ene coupling. The reaction was carried out between cardanol and thioglycerol in the presence of Irgacure 184 (photoinitiator) and 1,8-Diazabicyclo[5.4.0]undec-7-ene (catalyst) under UV light for 12 h at 80 °C. After completion of the reaction, one mole of thioglycerol was successfully added across the double More >

S. Michałowski¹, M. A. Mosiewicki^2*, M. Kuran´ska¹, M. I. Aranguren², A. Prociak¹

Journal of Renewable Materials, Vol.6, No.4, pp. 426-437, 2018, DOI:10.7569/JRM.2017.634163

Abstract Elastomeric polyurethanes were prepared from a reference polyurethane system modified with biobased polyols synthesized using rapeseed or palm oils. The reference material was modified by replacement of the commercial polyol by 10% of biopolyols and also by addition of sisal fibers up to 5 wt%. The higher functionality of the biopolyols increased the crosslinking density of the networks and this was reflected by an increase in hardness and a decrease in water absorption. The effect of the sisal fibers mainly improved the mechanical and thermomechanical properties of the system with rapeseed oil because of good More >

F.J. Santiago-Medina¹, M.C. Basso¹, A. Pizzi^1,2,*, L. Delmotte³

Journal of Renewable Materials, Vol.6, No.4, pp. 413-425, 2018, DOI:10.7569/JRM.2017.634172

Abstract The reaction of a desulphurized kraft lignin with hexamethylene diamine and dimethyl carbonate has allowed the development of isocyanate-free polyurethane resins. The present research work is based on previous studies made with hydrolyzable and condensed tannins, but takes advantage of the higher number of hydroxyl groups present in lignin and their different aliphatic and aromatic character. The obtained materials were analyzed by Fourier transform infrared (FTIR) spectroscopy, matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry and solid-state cross-polarization/magic angle spinning (CP MAS) 13 C nuclear magnetic resonance (NMR), which have revealed the presence of urethane More >