A. Abolins*, V. Yakushin and D. Vilsone

Journal of Renewable Materials, Vol.6, No.7, pp. 737-745, 2018, DOI:10.32604/JRM.2018.00119

Abstract Linseed oil was epoxidized using hydrogen peroxide (H2O2), acetic acid (AcOH) and ion exchange resin Amberlite IR-120 as a catalyst. Epoxidized oil was separately dissolved in isopropyl alcohol (IPA) or diethylene glycol butyl ether (DGBE) and phosphorylated with different amounts of phosphoric (H3PO4) acid (1%, 2%, 3% and 5%). The formation of phosphate polyesters was confirmed by Fourier-transform infrared (FTIR) and 31P nuclear magnetic resonance (NMR) spectra. Based on the synthesized polyols, polyurethane (PU) coatings were prepared. PU coating based on linseed oil diethylene glycol ester polyol was used as the reference. For the characterization of coatings, mechanical tests and… 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 >

Edgars Vanags*, Mikelis Kirpluks, Ugis Cabulis and Zuzana Walterova

Journal of Renewable Materials, Vol.6, No.7, pp. 764-771, 2018, DOI:10.7569/JRM.2018.634111

Abstract In this work, free tall oil fatty acids were epoxidized with in-situ generated peroxyacetic acid. Reaction kinetics of epoxidation was investigated by oxirane content and iodine value titrimetric determination, as well as FTIR spectra analysis. A highly functional biobased polyol was synthesized by functionalizing epoxidized tall oil fatty acids with triethanolamine using Montmorillonite K10 as a catalyst. The obtained polyol was analyzed by FTIR and MALDI-TOF MS. The most common chemical and physical characteristics of obtained polyol were determined. More >

Maha L. Shrestha^1,2,*, Mihail Ionescu¹, Xianmei Wan¹, Thomas Upshaw³

Journal of Renewable Materials, Vol.6, No.6, pp. 630-641, 2018, DOI:10.7569/JRM.2018.634106

Abstract Aromatic-aliphatic polyols were obtained previously from the thiol-ene reactions of propoxylated cardanol with hydroxyalkyl mercaptans; these aromatic-aliphatic polyols were then utilized in the preparation of rigid polyurethane foams with excellent properties. The current work describes a variant of cardanol polyol synthesis by thiol-ene reactions in three steps. The first step is propoxylation of cardanol by reacting cardanol with propylene oxide; the second step is mercaptanization of propoxylated cardanol by reacting double bonds with hydrogen sulfide; and the third step involves the addition of the thiol groups of mercaptanized propoxylated cardanol to the double bonds of allyl alcohol, glycerol-1-allyl ether, and… More >

Marwa Abida^1,2, Jamel Mars^3,*, Florian Gehring¹, Alexandre Vivet¹, Fakhreddine Dammak³

Journal of Renewable Materials, Vol.6, No.5, pp. 464-476, 2018, DOI:10.32604/JRM.2018.01897

Abstract Based on experimental test results, flax fiber reinforced polymer composites are characterized by nonlinear visco-elastoplastic behavior. The aim of this work is to model the quasi-unidirectional flax fiber reinforced composite behavior through a three dimensional formulation with orthotropic elasticity and orthotropic plasticity using Hill criterion. The isotropic hardening and Johnson Cook parameters are identified from unidirectional tensile tests at different strain rates. The adjustment of Hill’s yield criterion is developed based on yield stresses obtained in tensile tests at different directions. The numerical integration of the constitutive equations is implemented in a user-defined material, UMAT subroutines for the commercial finite… More >

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 morphological properties were investigated. The… More >

N. A. Sri Aprilia¹, M. S. Nurul Atiqah², Zhari Ismail³, C. Y. Loo², Chaturbhuj K. Saurabh², Rudi Dungani⁴, Abdul Khalil H.P.S^2*

Journal of Renewable Materials, Vol.5, No.5, pp. 380-387, 2017, DOI:10.7569/JRM.2017.634130

Abstract Due to environmental concerns, green composites have become a highly researched material. In the present study, kenaf fiber was used as reinforcement in epoxy-based composite with weight fraction ranges from 0, 5, 10, and 15% (w/w of resin). The ratio of epoxy to hardener was 65:32.5. Prior to incorporation, kenaf bast fiber underwent Soda-AQ pulping followed by total chlorine-free bleaching (OAZP sequence). The obtained pulp was then subjected to supercritical carbon dioxide extraction (SCE) treatment. It was observed that epoxy composite with 10% of fiber loading demonstrated the highest mechanical properties with a tensile strength of 64 MPa, tensile modulus… More >

Xiaoying Li¹, Xiaoan Nie^1,2*, Jie Chen¹, Yigang Wang¹, Ke Li¹

Journal of Renewable Materials, Vol.5, No.2, pp. 154-164, 2017, DOI:10.7569/JRM.2017.634101

Abstract Cardanol, an agricultural by-product of the industrial processing of cashew, was used to synthesize epoxidized cardanol laurate (ECDL) plasticizer. The target product was characterized using FTIR, 1H NMR and 13C NMR. The plasticizing effect of ECDL substitution for petroleum-based plasticizer dioctyl phthalate (DOP) in soft poly(vinyl chloride) (PVC) was investigated using dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA) and mechanical testing, and compared to PVC incorporated with commercial epoxidized soybean oil (ESBO). When DOP was partially substituted by EDCL, there was a slight increase of 5% in glass transition temperature (Tg) and a maximum increase of 14.55% in the elongation… More >

A. Sammaiah¹, K. V. Padmaja¹, K. I. Suresh^*,2, R. B. N. Prasad¹

Journal of Renewable Materials, Vol.4, No.2, pp. 113-122, 2016, DOI:10.7569/JRM.2015.634118

Abstract This article reports the effect of epoxidized jatropha oil (EJO) on the thermal, cure and viscoelastic properties of epoxy resins. Epoxidized jatropha oil with an oxirane value of 5.0 was prepared and epoxy formulations containing different concentrations of EJO were evaluated for cure, morphology, thermal and viscoelastic properties. The curing temperature of the formulations increased with increasing EJO content. The glass transition temperature of the cured films decreased from 56 °C for unmodified epoxy resin to 23 °C for the sample with 60 wt% EJO reactive diluent, suggesting good plasticizing action. The thermal decomposition was only marginally affected. More >

Wei Huang^∗,†, Yi Wah Mak^*, Peter C. Y. Chen^‡§

Molecular & Cellular Biomechanics, Vol.8, No.2, pp. 91-104, 2011, DOI:10.3970/mcb.2011.008.091

Abstract A molecular configuration tensor Pij was introduced to analyze the distribution of fibrous proteins in vascular cells for studying cells and tissues biomechanics. We have used this technique to study the biomechanics of vascular remodeling in response to the changes of blood pressure and flow. In this paper, the remodeling of the geometrical arrangement of F-actin fibers in the smooth muscle cells in rat's pulmonary arteries in hypoxic hypertension was studied. The rats were exposed to a hypoxia condition of 10% for 0, 2, 12, and 24 hr at sea level. Remodeling of blood vessels were studied at the in… More >