Cellulose samples from cotton linters, sisal, and sugar cane bagasse have been successively acylated (acetate, propionate, butyrate, and acetate/butyrate) under homogeneous reaction conditions, in LiCl/N,N-dimethylacetamide (DMAC), by the following procedure: (i) cellulose and LiCl are heated under reduced pressure, at 110°C; (ii) cellulose is dissolved in LiCl/DMAC by heating at 155°C, followed by cooling to 40°C; (iii) the solubilized polymer is acylated at 60°C for 18 h. Attractive features o...
In this work the performance of thermoset phenolic/sugar cane bagasse composites were ascertained as a function of fiber content and matrix modification. The matrix was modified by using lignin, extracted from sugar cane bagasse, as a partial (40% wt) phenol substitute. The thermoset polymer matrices and related composites were compression moulded and the products were characterized by TG, DSC, DMTA, Impact Strength, Shore D Hardness. Our results indicate that phenol can be substituted by lignin...
Commercially available cellulose (Avicell PH101) was successfully acylated under homogeneous solution conditions by the following procedure: 2.0 g of cellulose were stirred with 75 mL of N,N-dimethylacetamide for 1 h at 150°C, 3.5 g of LiCl were added, the temperature was raised to 170°C, ca. 18.5 mL of the solvent were distilled and the suspension was cooled to room temperature and stirred overnight. The temperature of the clear cellulose solution was raised to 110°C, kept at that temperature f...
The mechanical properties of tossa jute fibers were improved by using NaOH treatment process to improve the mechanical properties of composites materials. Shrinkage of fibers during this process has significant effects to the fiber structure, as well as to the mechanical fiber properties, such as tensile strength and modulus. Isometric NaOH-treated jute yarns (20 min at 20°C in 25% NaOH solution) lead to an increase in yarn tensile strength and modulus of ∼ 120% and 150%, respectively. These cha...
#2R. Ramaswamy(VSSC: Vikram Sarabhai Space Centre)H-Index: 15
Resole phenolic resins containing various p-cresol (PC) to phenol (P) mol ratios were prepared and characterized. These phenolic resins were blended with nitrile rubber (NBR) and the measurements of adhesive joint strength, stress–strain properties, DSC, TGA, DMA, TEM, and SEM were performed using a 50 : 50 NBR/phenolic resin blend. It was observed that the adhesive joint strength and the mechanical properties of the blend enhanced significantly on incorporation of p-cresol into the phenolic res...
The notched and unnotched Izod impact properties of a series of phenolic-glass composites following thermal exposure at 180°C, 300°C, and 800°C have been investigated. Four phenolic resins; a resol, a novolac, a resol/novolac blend, and a furan-novolac/resol copolymer were used to prepare the composites. The notched and unnotched impact properties of all S-glass composites improved following thermal exposure at 180°C for times up to 28 days. The best results at 180°C were obtained for the copoly...
A kraft lignin phenol formaldehyde resin with half the normal amount of phenol used in phenol formaldehyde resin replaced with kraft lignin was prepared on an industrial scale and used as an adhesive in the industrial production of plywood. The resin production, as well as the application of the resin in plywood manufacturing, could be performed without any changes in the normal industrial routine. It was necessary to increase the hot-press time of the kraft lignin-containing resin by approximat...
Last. Sabu Thomas(Mahatma Gandhi University)H-Index: 114
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Abstract The electrical properties of short-sisal-fiber-reinforced low-density polyethylene composites have been studied. Various surface treatments such as alkali, CTDIC, stearic acid, peroxide, permanganate and acetylation were carried out on the sisal fibers to improve interfacial bonding. The treated surfaces were characterized by infra-red spectroscopy. The dielectric constant increases progressively with increase in fiber loading and decreases with increase in frequency for all composites....
The hot-wire standard technique, mostly used for ceramic materials, was adapted to determine the thermal conductivity of nylon 6,6, polypropylene, poly(vinyl chloride), and poly(methyl methacrylate). The results obtained showed that the hot-wire standard technique can be used with accuracy and reproducibility to measure the thermal conductivity of polymers. In the second stage, to verify the effect of the use of a lignin (a “macromonomer”) in the thermal conductivity of phenolic resins, this tec...
The need to reduce solid waste continues to increase as landfills continue to close. OEMs, molders, and material suppliers need to address the issue of recycling molded scrap, including sprues, runners and used parts. Additional responsibility has been placed on suppliers of thermosetting materials, such as phenolics, because of the miscon ception that cured thermosetting materials are not recyclable.
Last. Mohammad Jawaid(UPM: Universiti Putra Malaysia)H-Index: 67
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Abstract In Malaysia, the majority of household electricity (45%) is consumed by air conditioning. Such high energy consumption is mainly caused by inefficient insulating materials with poor thermal performance. Hence, the selection of a thermal wall insulator with low thermal conductivity is vital to reduce the energy consumption. Utilizing agro waste based thermal insulation materials has become an efficient and economical method for energy efficient building. In this review, the standards req...
Phenolic, a thermoset polymer are among the most adaptive materials utilized by hundreds of industries. Phenol reacts with formaldehyde under either acidic or basic (alkali) conditions for formation structure of novolac and resol phenolic resin. Bio-phenolic or known as modified phenolic was introduced due to formaldehyde was assessed carcinogen with genotoxicity; harmful for respiratory system. This review article is intended to present an overview on the phenolic, types and chemical structure ...
Abstract The waste sugarcane dry leaves were utilized as the reinforcement with the epoxy matrix to prepare the sugarcane dry leaves reinforced polymer composites (SDLRPCs). The tensile, compressive, impact and flexural tests were conducted following respective ASTM standards. The proportion of SDL in SDLRPCs for the most effective fiber–matrix interaction was determined. The statistical analysis has confirmed that the error in experimental results was within the specified limits. The resistance...
Abstract Polyurethanes are synthesized from polyols, which can be fossil- or plant-sourced. The goal of this study was to investigate how the use of plant-sourced polyols, i.e., the ricinoleic acid triglyceride (the main component of castor oil, CO) and lignosulfonate, impacts the properties of the materials, as well as of their composites reinforced with sisal fibers. To reach this objective, the properties of polyurethanes from plant-sourced polyols were compared with those of their counterpar...
#1Shireen Quereshi(IITs: Indian Institutes of Technology)H-Index: 5
#2Tarun Kumar Naiya(IITs: Indian Institutes of Technology)H-Index: 13
Last. Suman Dutta(IITs: Indian Institutes of Technology)H-Index: 16
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The Indian sugar industry’s growth and residual lignocellulosic sugarcane bagasse (RSB) generation rate are complementary to each other. It is estimated that over 75–90 million tonnes of wet RSB are produced annually from 600 operational sugar mills in India. Therefore, the efficient utilization of residual bagasse needs immediate attention from sugar industries and the scientific community worldwide. Albeit recently developed technologies have shown promising prospects for the sustainable conve...
Last. Renato Carrhá Leitão(Empresa Brasileira de Pesquisa Agropecuária)H-Index: 15
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Abstract The experimental central composite design 22 was applied to optimize the acetosolv process for lignin extraction from sugarcane bagasse, with an aim to replace the petroleum-derived phenols conventionally used for resin production. The highest acetosolv extraction yield (55% ± 4.5%) was achieved with an acetic acid concentration of 95% (w/w), containing 0.1% (v/v) HCl, at 187 °C for 40 min. Other optimal conditions for extraction, such as 187 °C, 15 min (OC187;15) and 205 °C, 15 min (OC...
Manufacturing plays a vital role in the development of a country. At present the trend of industrialists is turned to green sustainable manufacturing which focuses on reduce, reuse and recycle concept for preparation of materials, products. On the other side petroleum based products are finite, create environmental problems and deplete in specific time period. So, the mankind on this earth has to definitely rely on renewable energy sources and sustainable inexhaustible materials. In the present ...
Unsaturated polyester (UP) resin has been blended with phenolic resin (PF) resole type at various ratios to obtain a homogeneous blend with improved flame resistance compared to its parent polymers. The polymer blend was reinforced with 20 wt% kenaf using hand lay out technique. Fourier transform infrared spectroscopy (FT-IR) was used to characterize changes in the chemical structure of the synthesized composites. The thermal properties of the composites were investigated using thermogravimetric...
Bioethanol is mainly produced from food sources, leading to criticisms regarding competition between food and fuels. The study of alternatives raw materials is very important. The reactions of hydrolysis of sisal bagasse were carried out in stainless steel reactor of high pressure. Sugar contents were determined by HPLC. The pretreatment was realized in the highest temperature and lowest acid concentration to obtain the maximum xylose concentration of 24,000 mg/L and maximum glucose concentratio...