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Molybdenum disulfide (MoS2) and Tungsten disulfide (WS2) nanoparticles addition to castor oil produce nano lubricants of novel properties. These nanomaterial additives are dispersed thoroughly in the liquid phase and are intended to boost the base fluid's thermo-physical, rheological, and tribological properties. All these properties have been studied by varying concentrations of nanoparticles from 0.05 to 2.5%. The size of both nanoparticles are in the range of <20nm. The density of nano lubricants was found to change with respect to nanoparticle concentration and temperature. The density increases from 0.06 to 0.6% with respect to the increase in concentration and decreases by 4%, for increasing temperature from 25 to 100 o C. A significant (15 %) increase in thermal conductivity with MoS2 nanoparticles in lubricants could be observed while with WS2 nanoparticles only 8 % enhancement was observed. The rheological study suggests that nano lubricants have better dynamic viscosity and shear stress than neat castor oil. A tribology study showed improved lubrication properties of the nanolubricants as compared with base castor oil. The addition of MoS2 and WS2 nanoparticles in castor oil decreased the friction coefficient by 53 % and 42 %, respectively, and reduced the wear scar diameter by 24% and 20 %, respectively, as compared to base castor oil. This study was done to develop nonedible vegetable oil based nanolubricants exploring their potential as emerging lubricants. [ABSTRACT FROM AUTHOR]

The application of vegetable oil based additive for lubricating oil has attracted considerable interest due to their biocompatibility and multifunctional performances compared to conventional additives. In the present work, we have synthesized homopolymer of castor oil and copolymer of castor oil with styrene by thermal method without any solvent at different percentage composition by using BZP (benzoyl peroxide) as initiator. Characterization of the additives was completed by spectral technique (FT-IR and NMR spectroscopy). The molecular weight of the prepared additives was determined by gel permeation chromatography method (GPC method). Thermo gravimetric analysis (TGA) method was used to study the thermal stability of the prepared polymers. Standard ASTM methods were used to investigate the performance of all the prepared polymers in SN150 mineral oil as viscosity index improver (VII), pour point depressant (PPD) and antiwear. Biodegradability of all the polymers was determined disk diffusion method. From the experimental results, it was found that copolymers are more effective as VII, PPD and antiwear than homopolymer. Moreover, average molecular weight, thermal stability and performances as VII and antiwear increase with increasing the percentage of styrene in copolymers. [ABSTRACT FROM AUTHOR]

The conventional flood cooling is neither economically viable nor eco-friendly in the cutting process. The vegetable oil is biodegradable and environmentally friendly used as base oil for the minimum quantity lubricant (MQL) cutting, but the temperature field in the milling zone with different vegetable oils as lubricants remains unclear. The temperature of the MQL milling of the 45 steel was studied with cottonseed, palm, castor, soybean, and peanut oils as base oils. The effects of the fatty acid composition, carbon chain length, thermal conductivity, and viscosity on the milling temperature were also considered. The temperature distribution of the milling of the 45 steel with five different vegetable oils was simulated, showing that the cottonseed and the palm oils had good cooling effect. Experimental results were consistent with the findings obtained using the temperature simulation analysis. Compared with that of the flood milling, the temperature of the MQL milling with different vegetable oils decreased, and the temperature was reduced by 67.4% when the cottonseed oil was used. The surface quality of the workpiece was improved during the MQL milling. When the cottonseed oil was used as lubricant, the surface roughness (Ra) values decreased by 41.5%, 53%, and 50.2% when the cottonseed, palm, and castor oils, respectively, were used as lubricating fluids, which indicated that the advantages of biolubricants as base oils especially cottonseed, palm, and castor oils could be used as base oils for the MQL milling. [ABSTRACT FROM AUTHOR]

The current study is devoted to the use of vegetable-oil fatty acids (FAs) as lubricity additives for modern diesel fuels with ultra-low sulfur contents. The effectiveness of liquid castor, linseed, coconut, and sunflower oils in the base components of diesel fuels for hydrotreating, hydrocracking, and hydroisomerization is comparatively evaluated. It is established that all investigated vegetable-oil FAs are effective anti-wear additives as compared to a commercially available additive while FAs of castor oil, which consist of 90% ricinoleic acid, are most effective as anti-wear additives. [ABSTRACT FROM AUTHOR]

• A new type of kinetic/anti-agglomerant methane hydrate inhibitors was proposed. • They were synthesized by simple way from castor oil using waterborne technique. • Synthesized castor oil based waterborne poly urea/urethanes (CWPUUs) are biodegradable. • CWPUUs significantly increase the induction time and decrease the temperature of methane hydrate formation. • CWPUUs prevent gas hydrate growth and aggregation. This study is devoted to the evaluation of vegetable oils (in this case castor oil) as an inexpensive, sustainable, environment-friendly, natural and promising resource to design/synthesis efficient kinetic/anti-agglomerant methane hydrate inhibitors. The castor-based waterborne polyurea/urethanes (CWPUUs) were synthesized on the basis of the waterborne technique. The high-pressure autoclave cell and high-pressure micro-differential scanning calorimeter (HP-μDSC) using methane gas were applied to evaluate the inhibition performance of CWPUUs as an inhibitor for methane gas hydrate formation. The results of gas uptake tests confirm that the CWPUUs show high efficiency as kinetic hydrate inhibitors (KHIs). The CWPUUs with ∼3.2 and 6.8 kD molecular weight delayed the onset time of methane hydrate formation by a factor of 26.8 and 13 times and reduced the methane hydrate growth rate by a factor of 3.8 and 2.5 times in comparison with pure water. The results were further confirmed through DSC measurements, in which the usage of CWPUUs with ∼3.2 and 6.8 kD molecular weight decreased the mean onset temperature of methane hydrate formation on 6.1 and 4.7 °C compared to pure water, respectively. Additives of CWPUUs (1 wt % solution) increased the mean onset time of methane hydrate formation from 2.3 h for pure water to 8.7 and 6.4 h. CWPUUs also demonstrated the thermodynamic inhibition by decreasing the melting temperature of methane hydrates comparing to the pure water system. On the other hand, the torque measurements were used to assess anti-agglomerant performance of CWPUUs. During the methane hydrate formation in the presence of CWPUUs, the torque changes remained constant that suggests the hydrate particles stayed separate without aggregation. Moreover, synthesized CWPUUs can be related to biodegradable substances because their BOD 5 /COD cr value measured in this work is equal to 0.389. Hence, the application of CWPPUs can be a prospective option for delaying the onset time/temperature of hydrate formation, reducing hydrate growth rate and preventing agglomeration of hydrate particles, and this strategy refers to the terms of green chemistry. [ABSTRACT FROM AUTHOR]

• Castor oil based polyurethane bioadhesives were prepared and characterized. • It provides a comprehensive method of plant oil based bioadhesive. • Final product presents good biocompatibility. • Polyurethane films have good thermal properties under certain temperature. Based on the stealth behavior of castor oil and poly(ethylene glycol), we selected a polyurethane system to obtain an ideal surgical adhesive. The polyurethane adhesives with varying concentrations of castor oil were investigated by Fourier transform infrared spectrometer, differential scanning calorimetry, scanning electron microscopy, goniometer, and universal testing machine. Curing results show that a 7-min to 25-min room temperature curing can be achieved, providing one possibility of shortening the surgery time. In vitro biodegradation test demonstrates that a certain proportion of the polyurethane film will be hydrolyzed in a foregone manner after a period of time (7 weeks). The adhesion strengths of these adhesives show a strong bonding between pieces of tissue, which makes them qualified for application in a moist environment. [ABSTRACT FROM AUTHOR]

Polymers based on vegetable oils can be suitable candidates for the replacement of fossil polymers, for instance, polyurethanes (PU) based on castor oil. However, the synthesis PU materials are normally carried out using organic solvents, metals, and high temperatures. To overcome these problems, the sol-gel route is an alternative approach based on mild conditions to produce organic-inorganic hybrid urethanesil (Ut) environmentally friendly. Therefore, in this study, we proposed an organic-inorganic hybrid (OIH) synthesis based on castor oil (CO)-derived Ut, as well as the incorporation and interaction of europium β-diketone [Eu(tta) 3 (H 2 O) 2 ] in organic-inorganic hybrid matrix. The Ut self-supporting hybrid was synthesized from the reaction of 3-(triethoxysilyl)propyl isocyanate (ICPTES) and CO in a 3:1 M ratio. The films were obtained using the sol-gel process, following the casting method. The CO-based OIH-Ut films showed high transmittance in the visible and infrared spectrum (90%), and urethanesil showed photoluminescence (PL) with emission at 416.0 nm when excited at 319.0 nm. The results also revealed an increase in the intrinsic quantum yield of PL (Q L E u ) for [Eu(tta) 3 (H 2 O) 2 ]. It has been verified a Q L E u value of 27% for the isolated complex, whereas when it is incorporated into OIH-Ut a value of 49% was observed. [Display omitted] [ABSTRACT FROM AUTHOR]

The development of eco-friendly lubricant is the requirement of the times. In this paper, the modified IF-WS 2 nanoparticles are added to castor oil as additives to prepare mixed lubricant. The lubrication performances of the mixed oil are investigated by ball-on-disc rotary friction tester, and then the surface scratches are characterized by depth of field digital microscope, scanning electron microscope and Raman spectrometer. Experiments reveal that compared with the base oil, the friction coefficient and worn volume decrease by 27.4% and 47.2% after adding modified IF-WS 2 as additives under 300 rpm and 5 N conditions, respectively. From mechanism analysis, this improvement in lubrication performance is attributed to the polarity of castor oil and the unique pressure bearing structure and dispersion stability of modified IF-WS 2 , which makes that the castor oil molecules can better adsorb around the modified IF-WS 2 to form heavy loading bearing friction oil film so as to reduce friction and wear. In summary, results indicate the mixture of modified IF-WS 2 nanoparticles and vegetable lubricating oil has an attractive prospect in the field of environmentally-friendly products. [Display omitted] • The chemical modification of IF-WS 2 is successfully carried out by oleic acid. • A new environment-friendly and efficient lubricating oil is synthesized. • Friction coefficient and worn volume decrease by 27.4% and 47.2%. • Anti-wear mechanism of modified IF-WS 2 nanoparticles in castor oil is studied. [ABSTRACT FROM AUTHOR]

This study provides a simple method for tailoring the performance of the WPUs by employing amino acids as environmentally-friendly proton sources, which eliminates long-standing issues of WPUs, such as irritating odor, corrosiveness, and air pollution. [Display omitted] • Novel WPU have been successfully prepared using amino acids as proton sources. • WPU ranging from flexible elastomers to tough plastics can be tailored by acids. • Tunability of hydrogen bonding confers UV protection and anti-bacterial to WPU. • Application of amino acid eliminates irritating odor, corrosiveness issues of WPU. Acids are traditionally used in the production of environmentally-friendly cationic waterborne polyurethane dispersions. However, the effect of their conjugate bases on the final properties of waterborne polyurethanes has been rarely explored. In this study, the effect of different acids in tailoring the performance of bio-based cationic waterborne polyurethanes has been reported. Polyurethane films ranging from flexible elastomers to tough plastics can be obtained, and their properties can be simply controlled by the selection of the acids. The tunability of the hydrogen bonding strength confers the resulting polyurethane films enhanced multi-function, such as UV absorption, anticorrosion properties, and long-term antibacterial performance. These results represent a significant advancement over traditional techniques, providing a simple strategy to tailor the performance of cationic waterborne polyurethanes, and offering environmentally-friendly amino acid substitutes for commonly used acids, such as acetic acid, HCl, or glycolic acid. The methodology described here eliminates long-standing issues of PUs, such as irritating odor, corrosiveness, and air pollution. [ABSTRACT FROM AUTHOR]

Biodegradable polyurethanes (PUs) were produced from castor oil (CO) and poly (3-hydroxybutyrate) diol (PHBD) using hexamethylene diisocyanate as a crosslinking agent. PHBDs of different molecular weights were synthesized through transesterification of bacterial PHB and ethylene glycol by changing the reaction time. The synthesized PHBDs were characterized in terms of Fourier transform infrared and proton nuclear magnetic resonance spectroscopy. A series of PUs at different NCO/OH and CO/PHBD ratios were prepared. The resulting CO/PHBD-based PUs were then characterized in terms of mechanical and thermal properties. Increasing PHBD content significantly increased the tensile strength of CO/PHBD-based PUs by 300% compared to neat CO-based PU. CO/PHBD-based PUs synthetized from short chain PHBD exhibited higher tensile strength compared to those produced from long chain PHBD. As revealed by scanning electron microscopy analysis, such improvement in stiffness of the resulting PUs is due to the good compatibility between CO and PHBD. Increasing PHBD content also increased the crystallinity of the resulting PUs. In addition, higher degradation rates were obtained for CO/PHBD-based PUs synthetized from long chain PHBD compared to neat CO PU and PUs produced from short chain PHBD. [ABSTRACT FROM AUTHOR]