Castor oil as a potential renewable resource for the production of functional materials
© The Author(s) 2016
Received: 23 November 2015
Accepted: 13 June 2016
Published: 15 July 2016
KeywordsCastor oil Ricinoleic acid Derivatization of castor oil Hydrogenated castor oil (HCO) Capping agent Nanomaterials
Castor plant (Ricinus communis) is from the family Euphorbiaceae and grows wild in varied climatic conditions. The plant produces castor seeds that contain up to 50 % castor oil by weight. The oil can easily be extracted from castor seeds and find its use in a multitude of sectors such as medicine, chemicals industry and in other technologies . The demand for castor oil and its products in the world market has been on the steady increase  partly due to their renewable nature, non-competition with food, biodegradability, low costs, and eco-friendliness. It is now estimated  that the oil has over 700 industrial uses and the uses keeps on increasing.
The chemistry of castor oil is mainly centered on ricinoleic acid due to its high content in the oil and the presence of the three functional groups in the acid. The three functionalities are crucial towards the versatility of the oil for the production of variety of castor oil based products. The carboxylic group for instance, can lead to a wide range of esterification products while the single point of unsaturation can be altered by hydrogenation, epoxidation or vulcanization. On the other hand, the hydroxyl functional group at carbon-12, can be acetylated, alkoxylated or removed by dehydration to increase the unsaturation of the oil.
The reactions of castor oil are becoming of high industrial importance. This paper reviews on the geographical distribution of castor plants and the world production of castor seeds and castor oil. Furthermore, some important reactions on converting castor oil into useful products is discussed. The reactions discussed include hydrogenation, pyrolysis, caustic fusion, dehydration, transesterification, sulphonation, and polymerization. The use of castor oil and ricinoleic acid as green capping agent in the synthesis of nanomaterials is highlighted.
Geographical distribution of castor plant and the world production of castor seeds
The world-wide increase in castor oil production witnessed in the past decade is a clear testimony of the wide range of applications of castor oil and its derivatives in various sectors. The oil is presently used in sectors such as agriculture, food, textile, paper, plastic, rubber, cosmetics, perfumeries, electronics, pharmaceuticals, paints, inks, additives, lubricants and biofuels [1, 8]. The advances made during the last decade in using plant oils and basic oleochemicals in the synthesis and production of diverse products including polymers is remarkable [9, 10]. In the advances, castor oil is among the most versatile plant oil owing to its unique chemical structure that makes it useful in a wide range of industries. It is among the most sought after plant oil mainly due to its rich properties and variety of end-uses.
Castor oil and derivatives global market
Owing to its rich properties and variety of end-uses, together with increased interests in biopolymer and bio-fuels industries, the potential for castor oil to play a much larger role in the world economy has increased dramatically in recent years. For instance, trend shows that castor oil prices steadily rose from $946 per tonne in 2002–2003 to $2390 in 2010–2011 . The contribution of castor oil on the world economy is expected to continue increasing and it has been predicted that the global castor oil and derivatives market will reach USD 1.81 billion by 2020 . The increased interest of substitution of conventional fuel by bio fuels, volatile crude oil prices, higher demand from Europe, China and the US, and growth of key end-use industries including cosmetics and lubricants are expected to drive the global castor oil and derivatives market. On the other hand, threat from other vegetable oils in terms of price and application, and high dependency on seasonality may hinder the market growth. Some major companies operating in the castor oil and derivatives global market are: Thai Castor Oil Industries Co. Ltd., Jayant Agro Organics, Hokoku Corporation, ITOH Oil Chemicals Co. Ltd., Gokul Overseas, Bom Brazil, Liaoyang Huaxing Chemical Co., Ltd., and Kanak Castor Products Pvt. Ltd .
Extraction, composition and properties of castor oil
Castor oil is extracted colourless to very pale yellow viscous liquid with a distinct taste, mild odour and it boils at 586 K . The hydroxyl group in ricinoleic acid (Fig. 4a) account for the unique properties of castor oil. For instance, the oil has relatively high viscosity and specific gravity; it is soluble in alcohols in any proportion and has limited solubility in aliphatic petroleum solvents . In addition, the polar hydroxyl group in castor oil makes it compatible with plasticizers of a wide variety of natural and synthetic resins, waxes, polymers and elastomers . Notable changes on the properties of the castor oil can also be due to several factors such as the method of extraction, seed varieties, weather conditions and soil type. For instance, cold-pressed castor oils have low acid value, low iodine value and a slightly higher saponification value than solvent-extracted oil . It has further been observed that castor seeds from different climatic conditions produce castor oils of different composition and physical–chemical properties [14, 15, 17]. Malaysian castor seeds for instance, contain total lipids (castor oil) reaching up to 43.3 % per dry weight and a saponification value of 182.96 mg KOH/g  while for the Nigerian castor seeds, the total lipids (castor oil) is 48 % per dry weight with a saponification value of 178.00 mg KOH/g .
Chemical transformations of castor oil
The unique properties and diverse applications of castor oil and its derivatives make castor oil popular and even more important among vegetable oils. The presence of ester linkage, a double bond and the hydroxyl group in ricinoleic acid favours the oil as a suitable renewable resource for many chemical reactions, modifications and transformations. The presence of carboxylic group for example, allow transformation of castor oil via several reactions such as esterification, amidation [13, 16, 18] whereas the presence of a double bond, affords the transformation of the oil through reactions such as hydrogenation [16, 19], carbonylation  and epoxidation . Furthermore, the hydroxyl functional group can be acetylated [21, 22] alkoxylated [23, 24] or removed by dehydration [25, 26] to increase the unsaturation of the oil. Catalytic dehydration leads into formation of a new double bond in the chain of ricinoleic acid resulting into a conjugated acid. This change imparts good flexibility, rapid drying, excellent color retention, and water resistance for protective coatings . Both ring-opened glyceryl ricinoleates and epoxy alkyl ricinoleates functionalized castor oil derivatives have recently been prepared with very high yields . The ring-opened glyceryl ricinoleates was achieved through catalytic ring opening and transesterification using epoxidized castor oil (ECO) as a raw material using Amberlyst 15 acid catalyst while the epoxy alkyl ricinoleates was achieved by transesterification of ECO with methanol using CaAl-layered double hydroxide base catalyst. Interestingly, the physical properties of these functionalized castor-based derivatives further demostrate the opportunity to design tailor-made materials suiting industrial needs from the oil.
Chemical transformations of castor oil into castor oil based products are discussed in the subsequent sections.
The semi-solid saturated ricinoleic acid is a valuable material in industries and in resin or polymer mixtures. The oil has high melting point, improved storage qualities, taste, and odor. Moreover, the hydrogenated oil has an improved oxidative and thermal stability. A good quality hydrogenated castor with high hydroxyl value and low iodine value is obtained at 423 K; 1.034 × 106 Pa; in 5 h with 2 % (weight of oil) Raney nickel catalyst . Hydrogenation of castor oil at low pressure (1.96–2.45 × 105 Pa) and low temperature (398–408 K) requires high catalyst concentration [29, 30].
Hydrogenated castor oil (HCO) is insoluble in water and in most organic solvents but it is soluble in hot organic solvents like ether and chloroform . This insolubility is among good qualities that make HCO valuable for lubricant industries because of water resistance and retention of its lubricity. Moreover, the polarity and surface wetting properties of HCO are useful in cosmetics, hair dressing, solid lubricant, paint additives, manufacture of waxes, polishes, carbon paper, candles and crayons .
Hydrolysis of castor oil
Both sebacic acid and capryl alcohol have many uses. The alcohol finds its uses as plasticizer, as a solvent, dehydrater, antibubbling agent and also as a floatation agent in coal industry . The esters of sebacic acid on the other hand are plasticizers for vinyl resins and are also used in the manufacture of dioctyl sebacate (DOS), a jet lubricant and lubricant in air cooled combustion motors [1, 38] Furthermore; sebacic acid is used as a monomer where it reacts with hexamethylenediamine to produce nylon 6–10 .
Transesterification reactions are reversible and therefore an excess alcohol is usually used to shift the equilibrium to the formation of the biodiesel. Generally transesterification reduces the molecular weight and thus reducing the viscosity of the castor oil which is not required in the biodiesel . Transesterification also increases the volatility while maintaining the cetane number and heating value of the biodiesel [43, 44].
Sulphation of castor oil
Sulphation refers to the introduction of SO3 group into an organic compound to produce the characteristic C-OSO3 configuration. Sulphation of castor oil produces sulphuric acid esters (Turkey-red oil) in which the hydroxyl group of ricinoleic acid has been esterified (Scheme 8) . The reaction is done by treating raw castor oil at room temperature or at temperature less than 308 Kwith concentrated sulphuric acid for 3–4 h.
Castor oil based polymers
The depletion of fossil fuels and environmental issues has necessitated researchers to focus their attention and efforts to the utilization of renewable resources as raw materials for the synthesis of polymeric materials. Bio-based polymers offer a number of advantages over polymers prepared from petroleum-based monomers as they are cheaper, readily available from renewable natural resources and they possess comparable or better properties. Some bio-based polymers are biodegradable, nontoxic and have low carbon footprints . Polyamides, polyethers, polyesters and interpenetrating polymer networks have been synthesized from castor oil [10, 39, 57–61]. Most of these castor oil polymers are particularly on the production of polyurethanes, polyamides and polyesters. In another development, the synthesis of interpenetrating polymer networks based on polyol modified castor oil polyurethane and poly(2-hydroxyethylmethacrylate) has been reported .
The 9-carbon fatty acids can be used as monomers in the preparation of condensation polymers such as polyurethane, polyethers and polyesters.
Polyurethane from castor oil monomers
Polyurethanes (PU) are polymers containing urethane linkages (–NHCOO–) in the main polymer chain. They are among the most important and versatile classes of polymers as they can vary from thermoplastic to thermosetting materials [62–68]. The industrial production of polyurethanes is normally accomplished through the polyaddition reaction between organic isocyanates and compounds containing active hydroxyl groups, such as polyols . From an environmental viewpoint, this method is not advantageous because it uses highly reactive and toxic isocyanates, which are commonly produced from an even more dangerous component, phosgene . In the search for green routes to the key polyurethane intermediates, fats and oils offer important alternatives for the production of diols, polyols, and other oxo chemicals, thus, enabling to substitute petrochemicals . Environmentally friendly production of polyurethanes is achieved using plant-derived diols and diisocyanates or using nonisocyanate chemistries . Polyurethanes prepared from vegetable oils exhibit a number of excellent properties that are attributable to its hydrophobicity. Castor oil as a source of polyols, is increasingly finding application in the manufacture of polyurethane. Polyurethane networks based on castor oil as a renewable resource polyol and poly(ethylene glycol) (PEG) with tunable biodegradation rates for biomedical implants and tissue engineering is documented elsewhere . The synthesis involved the reaction of epoxy-terminated polyurethane prepolymers (EPUs) from castor oil with 1,6-hexamethylene diamine curing agent. This is interesting given that there are a limited number of naturally occurring triglycerides which contain the unreacted hydroxyl groups and castor oil being the only commercially-available natural oil polyol that is produced directly from a plant source as all other natural oil polyols require chemical modification prior to their use . Polyurethane derived from castor oil find their applications in areas such as biomedical implants, coatings, cast elastomers, thermoplastic elastomers, rigid foams, semi-rigid foams, sealants, adhesives and flexible foams.
Methoxycarbonylation of undecylenic acid derived from castor oil
Overall, growth of biopolymers from castor oil industries makes the oil potential for it to play a much larger role in the world economy on polymers and to humanity.
Green synthesis of nanomaterials using castor oil or ricinoleic acid
The high percentage of ricinoleic acid and its structural features makes castor oil capable of forming covalent dative bonds with active surface dangling orbitals of chalcogenides quantum dots. Green synthesis of chalcogenides nanomaterials using castor oil and its isolate ricinoleic acid as eco-friendly bio-based capping agents have recently been reported [73–79]. This is environmentally interesting because the use of castor oil and ricinoleic acid as both capping and dispersing agents, eliminate the need for the use of air-sensitive, toxic and expensive chemicals such as trioctylphosphine (TOP), trioctylphosphine oxide (TOPO) and alkyl amines. It is worth noting that the boiling points of castor oil and ricinoleic acid are 586 and 685 K, respectively and thus they are simple to work with since they are liquid at room temperature. Literature reports the high ability of castor oil to prevent agglomeration of the synthesized nanoparticles due to the presence of long-chain hydrophobic moieties, thus forming ultra-small, well dispersed and stable quantum dots for a long period of time [76–79]. Some of these nanomaterials synthesized using castor oil or ricinoleic acid can be suitable for biological and medical applications because no toxic reagents are used in their preparation .
The diversity of chemicals and products produced from castor oil has proven that castor is an important and potential non-edible oilseed crop. The great utilitarian value in industry, agriculture, cosmetics and pharmaceutical sectors is a direct proof that castor oil is a potential bio-based starting material. The presence of a hydroxyl group, carboxylate and double bonds in the ricinoleic acid, imparts unique properties for the derivatization of castor oil into vital industrial raw materials. It has been shown how castor oil can be used as a renewable bio-based raw material for the production a multitude of functional materials. It is equally noted that the diverse possibilities of castor oil transformation mainly depend on the presence of the three functional groups. This review has further shown that castor oil is a potential alternative to petroleum-based starting materials for the production of wide range of industrial materials. It can also be seen that apart from the oil’s unique chemical structure and environmental considerations, the worldwide growth in castor oil demand is due to its easy availability, low cost, non-food competition. It has been observed in the discussion that castor oil is more than just a bio-based raw material in great demand by the chemical industries but its use as a fuel is also seen when transesterification is done. The worldwide increase in the production of castor seeds and castor oil testifies the huge potential as a green bio-resource for chemical transformations because castor oil can be used as the starting material for producing a wide range of end-products.
Dr. E. B. Mubofu obtained his Ph.D. in June 2002 from the University of York, UK where he worked on novel environmentally benign supported palladium catalysts under the supervision of Prof. Dr. James H. Clark and Dr. Duncan Macqurrie in the green chemistry group. He was a postdoctoral fellow for 2 years (2001–2003) at the University of Groningen, Stratingh Institute. In his postdoctoral tenure in the physical organic chemistry group; he worked on the use of water as an alternative cleaner and green solvent for performing Lewis acid catalysed Diels–Alder reactions under the guidance of Prof. Dr. Jan Engberts. In December 2003, he returned to Tanzania and joined the Chemistry Department, University of Dar es Salaam as a lecturer. He is now a senior lecturer since 2008 and is the chairman of the Department since 2012. EBM research interests are on Green Chemistry, nanomaterials and catalysis. He is involved with the novel chemical modification of nanomaterial surfaces and their application to different reactions, such as acid-catalysed reactions, water treatment, drug-delivery, catalytic oxidations and carbon–carbon bond forming transformations. He is heavily involved on the synthesis of nanomaterials using locally and cheaply available renewable bio-based capping agents for various applications. He has developed several palladium/copper heterogeneous catalysts (metal and biocatalysts) using chemically modified MTS with cashew nut shell liquid (CNSL) surfactant. He has authored or co-authored several publications in international journals on the use of renewable resources to generate functional materials.
I would like to acknowledge the National Research Foundation and the Commission for Science and Technology through NRF-COSTECH project for partial financial support to this work. Mr. James Mgaya and Mr. Athumani Omari are acknowledged for their assistance in writing the manuscript and for their technical assistance.
The author declares no competing interests.
Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
- Ogunniyi DS (2006) Castor oil: a vital industrial raw material. Bioresour Technol 97:1086–1089View ArticleGoogle Scholar
- Bagali S, Shridhar K, Beena KV, Anita VM, Paramjeet BK (2010) Optimization and characterization of castor seed oil. Leornard J Sci 17:1–10Google Scholar
- Salihu BZ, Gana AK, Apuyor B (2014) Castor oil plant (Ricinus communis L.): botany, ecology and uses. IJSR 3:1333–1341Google Scholar
- Severino LS, Auld DL, Baldanz M, Candido MJD, Chen G, Crosby W, Tan D, He X, Lakshmamma P, Lavanya C, Machado OLT, Mielke T, Milan M, Miller TD, Morris JB, Morse SA, Narvas AA, Soares DJ, Sofiatt V, Wang ML, Zanotto MD, Zieler HA (2012) Review on the challenges for increased production of castor. Agron J 104:853–880View ArticleGoogle Scholar
- Pavaskar M, Kshirsagar A (2013) Global castor oil and Indian monopoly. Financial Vis 1:15–19Google Scholar
- James S (2016) Castor oil and derivatives market trend, growth, research and analysis to 2020. https://www.linkedin.com/pulse/castor-oil-derivatives-market-trend-growth-research-analysis-james. Accessed 18 Apr 2016
- Grand view research. Castor oil and derivatives market analysis by product (sebacic acid, undecylenic acid, castor wax, dehydrated castor oil), by application (lubricants, surface coatings, biodiesel, cosmetics & pharmaceuticals, plastics & resins) and segment forecasts to 2020. http://www.grandviewresearch.com/industry-analysis/castor-oil-derivatives-industry. Accessed 18 Apr 2016
- Dasari SR, Goud VV (2013) Comparative extraction of castor seed oil using polar and non polar solvents. IJCET Spec Issue 1:121–123Google Scholar
- Biermann U, Bornscheuer U, Meier MAR, Metzger JO, Schfer HJ (2011) Oils and fats as renewable raw materials in chemistry. Angew Chem Int Ed 50:3854–3871View ArticleGoogle Scholar
- Yeganeh H, Hojati-Talemi P (2007) Preparation and properties of novel biodegradable polyurethane networks based on castor oil and poly(ethylene glycol). Polym Degrad Stab 92(3):480–489View ArticleGoogle Scholar
- Gana AK, Yusuf AF, Apuyor B (2013) Castor oil plant and its potentials in transformation and industrialization of under developing nations in the world. Adv J Agric Res 1:72–79Google Scholar
- Imankulov N (2012) Preparation and research on properties of castor oil as a diesel fuel additive. ATI 6:30–37View ArticleGoogle Scholar
- G. R. O’Shea Company, www.groshea.com, August 2015
- Salimon J, Noor DAM, Nazrizawati AT, Firdaus MYM, Noraishah A (2010) Fatty acid composition and physicochemical properties of Malaysian castor bean Ricinus communis L. seed oil. Sains Malaysiana 39:761–764Google Scholar
- Nangbes JG, Nvau JB, Buba WM, Zukdimma AN (2013) Extraction and characterization of castor (Ricinus Communis) seed oil. IJES 2:105–109Google Scholar
- Alwaseem H, Donahue CJ, Marincean S (2014) Catalytic transfer hydrogenation of castor oil. J Chem Educ 91:575–578View ArticleGoogle Scholar
- Omari A, Mgani QA, Mubofu EB (2015) Fatty acid profile and physico-chemical parameters of castor oils in Tanzania. Green Sustain Chem 16:154View ArticleGoogle Scholar
- Deshpande DP, Haral SS, Gandhi SS, Ganvir VN (2012) Transesterification of castor oil. ISCA J Eng Sci 1:2–7Google Scholar
- Sreenivasan B, Kamath NR, Kane JG (1957) Studies on castor oil II. Hydrogenation of castor oil. JACS 34:302–307Google Scholar
- Marc RL, Furst MRL, Le Goff R, Quinzler D, Mecking S, Botting CH, Cole-Hamilton DJC (2012) Polymer precursors from catalytic reactions of natural oils. Green Chem 14:472–477View ArticleGoogle Scholar
- Sinadinovic-Fiser S, Jankovic M, Borota O (2012) Epoxidation of castor oil with peracetic acid formed in situ in the presence of an ion exchange resin. Chem Eng Process 62:106–113View ArticleGoogle Scholar
- Grummitt O, Fleming H (1945) Acetylated castor oil, preparation and thermal decomposition. Ind Eng Chem 37:485–491View ArticleGoogle Scholar
- Mukherjea RN, Saha KK, Sanyal SK (1978) Plasticizing effect of acetylated castor oil on castor oil-based, moisture-cured polyurethane film. J Am Oil Chem Soc 55:653–656View ArticleGoogle Scholar
- Zhang Q, Sun Y, Zhi L, Zhang Y, Di Serio M (2015) Properties of ethoxylated castor oil acid methyl esters prepared by ethoxylation over an alkaline catalyst. J Surfactants Deterg 18:365–370View ArticleGoogle Scholar
- Bhowmick DN, Sarma SAN (1977) Dehydration of castor oil. Ind Eng Chem Prod Res Dev 16:107–111View ArticleGoogle Scholar
- Nezihe A, Elif D, Yılmaz O, Tuncer EA (2011) Microwave heating application to produce dehydrated castor oil. Ind Eng Chem Res 50:398–403View ArticleGoogle Scholar
- Sankaranarayanan S, Srinivasan K (2015) Preparation of functionalized castor oil derivatives with tunable physical properties using heterogeneous acid and base catalysts. RSC Adv 5:50289–50297View ArticleGoogle Scholar
- Naughton FC (1974) Production, chemistry and commercial applications of various chemicals from castor oil. J Am Oil Chem Soc 51:65–71View ArticleGoogle Scholar
- Rao HS, Chari KS, Aggarwal JS (1962) Hyrogenation of castor oil: part I-Influence of variables on hydrogenation efficiency. J Sci Industr Res 21D:89–92Google Scholar
- Trivedi RK, Vasishtha AK (1988) Low pressure hydrogenation of castor oil. J Am Oil Chem Soc 65:1467–1469View ArticleGoogle Scholar
- Smidovnik A, Stimac A, Kobe J (1992) Catalytic transfer hydrogenation of soybean oil. J Am Oil Chem Soc 69:405–409View ArticleGoogle Scholar
- Devi BL, Karuna MSL, Rao KN, Saiprasad PS, Prasad RBN (2003) Microwave-assisted catalytic transfer hydrogenation of sunflower oil. J Am Oil Chem Soc 80:1003–1005View ArticleGoogle Scholar
- Kulkarni Mangesh G, Sawant Sudhirprakash B (2003) Some physical properties of castor oil esters and hydrogenated castor oil esters. Eur J Lip Sci Technol 105:214–218View ArticleGoogle Scholar
- Lin CSK, Mubofu EB, Budarin V, Lam G, Kwan D (2015) Pretreatment and thermo-chemical and biological processing of biomass. In: Clark J, Deswarte F (eds) Introduction to chemicals from biomass, 2nd edn. Wiley, New York, pp 53–88Google Scholar
- Maher KD, Bressler DC (2007) Pyrolysis of triglyceride materials for the production of renewable fuels and chemicals. Bioresour Technol 98:2351–2368View ArticleGoogle Scholar
- Datta S, Chavan P, Saha S, Sahu G, Mall BK (2011) Synthesis of biodiesel by pyrolysis of castor oil. Asian J Chem 23:2614–2618Google Scholar
- Lligadas G, Ronda JC, Cadiz V (2010) Oleic and undecylenic acids as renewable feedstocks in the synthesis of polyols and polyurethanes. Polymers 2:440–453View ArticleGoogle Scholar
- Vasishtha AK, Trivedi RK, Das G (1990) Sebasic acid and 2-octanol from castor oil. J Am Oil Chem Soc 67:333–337View ArticleGoogle Scholar
- Mutlu H, Meir MAR (2010) Castor oil as a renewable resource for chemical industry. Eur J Lipid Sci Technol 112:10–30View ArticleGoogle Scholar
- Ramamurthi S, Manohar V, Mani VVS (1998) Characterization of fatty acid isomers in dehydrated castor oil by gas chromatography and gas chromatography-mass spectrometry techniques. J Am Oil Chem Soc 75:297–1303View ArticleGoogle Scholar
- Nakarmi A, Joshi SA (2014) Study on castor oil and its conversion into biodiesel by transesterification method. NJST 15:45–52Google Scholar
- Encinar JM, Gonzalez JF, Pardal A, Martinez G (2010) Transesterification of rapeseed oil with methanol in the presence of various co-solvents, Venice Third International Symposium on Energy from Biomass and Waste
- Sreenivas P, Mamilla VR, Sekhar KC (2011) Development of biodiesel from castor oil. IJES 1:192–197Google Scholar
- Bello EI, Mogaji TS, Agge M (2011) The effects of transesterification on selected fuel properties of three vegetable oils. J Mech Eng Res 3:218–225Google Scholar
- Yang F, Hanna MA, Sun R (2012) Value-added uses for crude glycerol, a by-product of biodiesel production. Biotechnol Biofuels 5:13View ArticleGoogle Scholar
- Nitayavardhana S, Khanal SK (2011) Biodiesel-derived crude glycerol bioconversion to animal feed: a sustainable option for a biodiesel refinery. Bioresour Technol 102:5808–5814View ArticleGoogle Scholar
- Jalasutram V, Jetty A (2011) Optimization of 1, 3-Propanediol production by Klebsiella pneumoniae 141B using Taguchi methodology: improvement in production by cofermentation studies. Res Biotechnol 2:90–104Google Scholar
- Rywinska A, Rymowicz W, Marcinkiewicz M (2010) Valorization of raw glycerol for citric acid production by Yarrowia lipolytica yeast. Electron J Biotechnol 13:1–9View ArticleGoogle Scholar
- Satpathy P, Thosar A, Rajan AP (2014) Green technology for glycerol waste from biodiesel plant. Int J Curr Microbiol App Sci 3:730–739Google Scholar
- Li C, Lesnik KL, Liu H (2013) Microbial conversion of waste glycerol from biodiesel production into value-added products. Energies 6:4739–4768View ArticleGoogle Scholar
- Diaz-Alvarez AE, Cadierno V (2013) Glycerol: a promising green solvent and reducing agent for metal-catalyzed transfer hydrogenation reactions and nanoparticles formation. Appl Sci 3:55–69View ArticleGoogle Scholar
- Zhao X, Cheng K, Liu D (2009) Organosolv pretreatment of lignocellulosic biomass for enzymatic hydrolysis. Appl Microbiol Biotechnol 82:815–827View ArticleGoogle Scholar
- Brioude MM, Guimarãesa DM, Fiúza RP, Prado LASA, Boaventura JS, José NM (2007) Synthesis and characterization of aliphatic polyesters from glycerol, by-product of bio-diesel production and adipic acid. Mater Res 10:335–339View ArticleGoogle Scholar
- Rangarajan S, Palaniappan NP (1958) Catalysts in sulfation of castor oil. Ind Eng Chem 50:1787–1788View ArticleGoogle Scholar
- Santhanam N, Balu M, Sreevatsan S Production and uses of key castor oil oleochemicals. Comprehensive castor oil report. www.castoroil. Accessed 17 Feb 2015
- Nayak PL (2000) Natural oil-based polymers. J Macromol Sci Polym Rev 40:1–21View ArticleGoogle Scholar
- Mallu P, Siddaramaiah V, Somashekar R (2000) Synthesis and characterization of castor oil-based polyurethane-polyacrylonitrile interpenetrating polymer networks. Bull Mater Sci 23:413–415View ArticleGoogle Scholar
- Prashantha K, Pai KVK, Sherigara BS, Prasannakumar S (2001) Interpenetrating polymer networks based on polyol modified castor oil polyurethane and poly (2-hydroxyethylmethacrylate): synthesis, chemical, mechanical and thermal properties. Bull Mater Sci 24:535–538View ArticleGoogle Scholar
- O’Lenick AJ, LaVay C (2002) Castor polyester for personal care. Cosmet Toiletr 117:59–64Google Scholar
- O’Lenick AJ, Dacula GA, LaVay C, Riverside CT (2002) Polymeric castor polyesters. United States Pat US 6(342):527Google Scholar
- Sokolsky-Papkov M, Shikanov S, Kumar N, Vaisman B, Domb AJ (2008) Fatty acid based biodegradable polymers-synthesis and applications. Israel Chem Soc 23:12–17Google Scholar
- Tabandeh S, Taromi FA, Nazockdast H (2014) Flexible polyurethane nanocomposite foam: synthesis and properties. Polym Sci Ser B 56:681–685View ArticleGoogle Scholar
- Ogunniyi DS, Fakayejo WRO (1996) Preparation and properties of polyurethane foams from toluene diisocyanate and mixtures of castor oil and polyol. Iran Polym J 5:56–59Google Scholar
- Barikani M, Barmar M (1996) Thermoplastic polyurethane elastomers: synthesis, and study of effective structural parameters. Iran Polym J 5:231–235Google Scholar
- Tran RT, Thevenot P, Gyawali D, Chiao J, Tang L, Yang J (2010) Synthesis and characterization of a biodegradable elastomers featuring a dual crosslinking mechanism. Soft Matter 6:2449–2461View ArticleGoogle Scholar
- Ismail EA, Motawie AM, Sadek EM (2011) Synthesis and characterization of polyurethane coatings based on soybean oil-polyester polyols. Egypt J Pet 20:1–8View ArticleGoogle Scholar
- Desai SD, Emanuel AL, Sinha VK (2003) Polyester polyol-based polyurethane adhesive; effect of treatment on rubber surface. J Polym Res 10:141–149View ArticleGoogle Scholar
- Chujo Y, Tatsuda T, Yamashita Y (1982) Synthesis of polyurethane graft copolymers by polyaddition reaction of dihydroxyl-terminated macromonomers. Polym Bull 8:239–244View ArticleGoogle Scholar
- Slocombe RJ, Hardy EE, Saunders JH, Jenkins RL (1950) Phosgene derivatives for the preparation of isocyanates, carbamyl chlorides and cyanuric acid. J Am Chem Soc 72:1888–1891View ArticleGoogle Scholar
- Figovsky O, Shapovalov L, Leykin A, Birukova O, Potashnikov R (2013) Recent advances in the development of non-isocyanate polyurethanes based on cyclic carbonates. Pu Mag 10:1–9Google Scholar
- Mol JC (2002) Application of olefin metathesis in oleochemistry: an example of green chemistry. Green Chem 4:5–13View ArticleGoogle Scholar
- Mgaya JE, Mubofu EB, Mgani QA, Bartlett S, Slawin AM, Pogorzelec P, Cole-Hamilton DJ (2016) Synthesis of bifunctional monomers via palladium catalyzed carbonylation of cardanol and its derivatives. Chem Cat Chem 8(4):751–757Google Scholar
- da Silva EC, da Silva MGA, Meneghetti SMP, Machado G, Alencar MARC, Hickmann JM, Meneghetti MR (2008) Synthesis of colloids based on gold nanoparticles dispersed in castor oil. J Nanopart Res 10:201–208View ArticleGoogle Scholar
- Wender H, de Oliveira LF, Feil AF, Lissner E, Migowski P, Meneghetti MR, Teixeira SR, Dupont J (2010) Synthesis of gold nanoparticles in a biocompatible fluid from sputtering deposition onto castor oil. Chem Commun 46:7019–7021View ArticleGoogle Scholar
- Zamiri R, Zakaria A, Abbastabar H, Darroudi M, Husin MS, Mahdi MA (2011) Laser-fabricated castor oil-capped silver nanoparticles. Int J Nanomed 6:565–568View ArticleGoogle Scholar
- Gherca D, Pui A, Cornei N, Cojocariu A, Nica V, Caltun O (2012) Synthesis, characterization and magnetic properties of MFe2O4 (M = Co, Mg, Mn, Ni) nanoparticles using ricin oil as capping agent. J Magn Magn Mater 324:3906–3911View ArticleGoogle Scholar
- Kyobe JW, Mubofu EB, Makame YMM, Mlowe S, Revaprasadu N (2015) CdSe quantum dots capped with naturally occurring biobased oils. New J Chem 39:7251–7259View ArticleGoogle Scholar
- Kyobe JW, Mubofu EB (2016) Makame YMM., Mlowe S, Revaprasadu N. Cadmium sulfide quantum dots stabilized by castor oil and ricinoleic acid. Physica E 76:95–102View ArticleGoogle Scholar
- Shombe GB, Mubofu EB, Mlowe S, Revaprasadu N (2016) Synthesis and characterization of castor oil and ricinoleic acid capped CdS nanoparticles using single source precursors. Mater Sci Semicond Process 43:230–237View ArticleGoogle Scholar
- Gebru H, Taddesse A, Kaushal J, Yadav OP (2013) Green synthesis of silver nanoparticles and their antibacterial activity. J Surf Sci Technol 29:47–66Google Scholar