Blends of Carboxymethyl Cellulose and Cottonseed Protein as Biodegradable Films.

With the increasing awareness of plastic pollution in the environment and the accumulation of microplastics in water, a significant amount of research and development is ongoing to replace the synthetic plastics in packaging and coatings. In this work, we explored the blends of carboxymethyl cellulose (CMC) and washed cottonseed meal (CSM, consisting mostly of cottonseed protein) as agro-based, biodegradable, and sustainable alternatives to plastics. Glycerol was found to be a suitable plasticizer for these blends. The blends of CMC/CSM were produced as single-layer films from 50 to 90 µm in thickness, consisting of different proportions of the components and plasticizer. The evaluated properties included opacity, water vapor permeability, mechanical properties, thermogravimetric analysis, moisture sorption analysis, and water swelling test. Higher percentages of CSM in the blend resulted in higher opacity and lower water vapor permeation rates. The mechanical strength waned with lower levels of CMC. Possible applications for these blends include their use as water-soluble food packaging and coatings and as dissolvable bags and pouches for detergents and agrochemicals.

Glycerol Monooleate (GMO): A Valuable Biobased Lubricity and Pour Point Enhancer Blend Component for the ULSD Fuel.

Novel value-added usage of glycerol (biodiesel coproduct) derivatives has been indispensable due to the extensive production of biodiesel. The physical properties of ultralow-sulfur diesel (ULSD) improved with the addition of technical-grade glycerol monooleate (TGGMO) with increasing concentration from 0.01 to 5 wt %. The influence of increasing concentration of TGGMO was studied on the acid value, cloud point, pour point, cold filter plugging point, kinematic viscosity, and lubricity of its blend with ULSD. The results showed improved lubricity for the blended ULSD with TGGMO as shown by the reduced wear scar diameter from 493 to 90 µm. The low-temperature flow properties were also improved as shown by lower pour points of -36 °C for the 1% TGGMO/ULSD blend compared to -25 °C for ULSDTGGMO blends in ULSD of up to 1 wt %, which met the ASTM standard D975 specifications. We also investigated the blending effect of the pure-grade monooleate (PGMO, purity level >99.98%) on the physical properties of ULSD at a blend concentration of 0.5 and 1.0%. Compared to PGMO, TGGMO significantly improved the physical properties of ULSD with increasing concentration from 0.01 to 1 wt %. Nevertheless, PGMO/TGGMO did not significantly affect the acid value, cloud point, or cold filter plugging point of ULSD. A comparison between TGGMO and PGMO showed that TGGMO improves the ULSD fuel lubricity and pour point more effectively than PGMO. PDSC data indicated that although addition of TGGMO will lower the oxidation stability slightly, it is still better than the addition of PGMO. Thermogravimetric analysis (TGA) data showed higher thermal stability and lesser volatility for TGGMO blends compared to those for PGMO blends. The cost effectiveness of TGGMO makes it a better ULSD fuel lubricity enhancer than PGMO.

Proof-of-Concept study of ion-exchange method for the recycling of LiFePO4 cathode.

Recycling spent lithium iron phosphate (LFP) cathodes in an economically sustainable way remains a great challenge due to their low-value elemental composition. Thus, both low-cost technology together with a high-value product are critical for the recovery of the LFP materials. In this study, the commercially mature ion-exchange (IX) method was explored to recover Li from LFP material for the first time. The feasibility of Li-H and Li-K IX reactions using strong and weak acid cation exchange resins was systematically investigated from the thermodynamic and kinetic perspectives. Different organic and inorganic acids were explored to obtain the feeding solution. The IX efficiency was greatly affected by the pH of the feeding solutions. Oxalic acid leaching solution with mild pH value and low iron impurity were determined to be the optimal feeding solution for IX reaction. The kinetics of IX and regeneration reaction were fast, and the resins can be reused several times without loss of IX capacity. Along with the P element remaining in the leaching solution, the Li-K IX reaction delivered a potential product of multi-elemental fertilizer. This simple and economical technology provides a practical recycling strategy for the spent LFP batteries.

Ultrasonic-promoted enzymatic preparation, identification and multi-active studies of nature-identical phenolic acid glycerol derivatives.

Phenolic acid glycerols (PAGs) are a group of rare phytochemicals found from potato periderm, which show great potential in the food, cosmetic and pharmaceutical industries. In this study, seven PAGs were enzymatically synthesized via transesterification of ethyl phenates (EPs) with glycerol by ultrasonic promotion. The conversions of 88.1-98.5% could be obtained in 1-9 h. Compared with the conventional stirring methods, the catalytic efficiency was significantly increased 11.0-44.0 folds by ultrasound assistance. The lipid peroxidation inhibition activity increased 8.1-fold and 14.4-fold compared to the parent phenolic acids (PAs). Furthermore, caffeoyl glycerol and feruloyl glycerol exhibited excellent antimicrobial activity against Escherichia coli compared to the corresponding PAs with minimum inhibitory concentration (MIC) decreasing 4-16-fold. The PAGs can also absorb a much wider and higher amount of the harmful UV-B rays than the corresponding PAs. The present strategy for facile synthesis of multifunctional PAGs paves the way for the development and application of natural phytochemicals and novel ingredients.

A renewable tung oil-derived nitrile rubber and its potential use in epoxy-toughening modifiers.

In this study, a modifier (CTMA) prepared by emulsion copolymerization of tung oil fatty acid, methyl esters of tung oil fatty acid and acrylonitrile was used to toughen epoxy resins. The structural characterization of the copolymer was carried out by Fourier transform infrared spectroscopy, 1H NMR spectroscopy and high-temperature gel permeation chromatography. Mechanical testing, thermal characterization and scanning electron microscopy were conducted to investigate the properties of epoxy resin modified by the copolymer and further reveal its toughening mechanism. The results indicated that the newly synthesized copolymer effectively toughened the epoxy resin because the elongation-at-break was increased to 89.48%, the maximum toughness calculated by work before break was nearly 4.6 times that of the neat epoxy resin, and apparent shear yields and plastic deformations were observed in the morphology of the fractured surfaces. CTMA, which acts as a flexible cross-linker in the epoxy thermoset, may decrease the cross-linking density.

Developing acrylated epoxidized soybean oil coating for improving moisture sensitivity and permeability of starch-based film.

Acrylated epoxidized soybean oil (AESO)-based coatings were developed to reduce moisture sensitivity and permeability of starch-based materials. The coating was applied on starch based films by dipping the samples on AESO-based coating solutions, followed by crosslinking with ultraviolet (UV) light. Effect of AESO concentration, photoinitiator content and processing conditions on the performance of coated starch-based film was systematically investigated, in particular the effect of coating on moisture absorption, permeability and mechanical properties. The modified surface was characterized by scanning electronic microscopy and Fourier transform infrared spectroscopy. The results showed that the moisture sensitivity of the starch-based sheets was reduced significantly since the crosslinked AESO acted as a hydrophobic layer. Moisture permeability was decreased more than 10 times after AESO treatment. It was found that the crosslinking density acted as one of the key factors, so even a very thin layer of AESO could achieve good water resistance.

High-Performance Biobased Unsaturated Polyester Nanocomposites with Very Low Loadings of Graphene.

Graphene-reinforced tung oil (TO)-based unsaturated polyester nanocomposites were prepared via in situ melt polycondensation intergrated with Diels⁻Alder addition. Functionalized graphene sheets derived from graphene oxide (GO) were then extracted from the obtained nanocomposites and carefully characterized. Furthermore, dispersion state of the graphene nanosheets in the cured polymer composites and ultimate properties of the resultant biobased nanocomposites were investigated. Mechanical and thermal properties of the TO-based unsaturated polyester resin (UPR) were greatly improved by the incorporation of GO. For example, at the optimal GO content (only 0.10 wt %), the obtained biobased nanocomposite showed tensile strength and modulus of 43.2 MPa and 2.62 GPa, and Tg of 105.2 °C, which were 159%, 191%, and 49.4% higher than those of the unreinforced UPR/TO resin, respectively. Compared to neat UPR, the biobased UPR nanocomposite with 0.1 wt % of GO even demonstrated superior comprehensive properties (comparable stiffness and Tg, while better toughness and thermal stability). Therefore, the developed biobased UPR nanocomposites are very promising to be applied in structural plastics.

Glycidyl Fatty Acid Esters in Refined Edible Oils: A Review on Formation, Occurrence, Analysis, and Elimination Methods.

Glycidyl fatty acid esters (GEs), one of the main contaminants in processed oils, are mainly formed during the deodorization step in the refining process of edible oils and therefore occur in almost all refined edible oils. GEs are potential carcinogens, due to the fact that they readily hydrolyze into the free form glycidol in the gastrointestinal tract, which has been found to induce tumors in various rat tissues. Furthermore, glycidol has already been identified as a "possible human carcinogen'' (group 2A) by the Intl. Agency for Research on Cancer (IARC). Therefore, significant effort has been devoted to inhibit and eliminate the formation of GEs. The aim of this review is to provide a comprehensive summary on the following topics: (i) GE occurrence data for different edible oils and oil-based food products, (ii) precursors of GEs, (iii) factors influencing the formation of GEs, (iv) potential reaction mechanisms involving the leaving group and reaction intermediates, and (v) analytical methods, including the indirect and direct methods. More importantly, the various elimination methods for GEs in refined edible oils are being reviewed with focus on 3 aspects: (i) inhibition and removal of reactants, (ii) modification of reactive conditions, and (iii) elimination of GE products.

Microwave-assisted synthesis of cyclodextrin polyurethanes.

Cyclodextrin (CD) has often been incorporated into polyurethanes in order to facilitate its use in encapsulation or removal of organic species for various applications. In this work a microwave-assisted method has been developed to produce polyurethanes consisting of α-, ß-, and γ-CD and three common diisocyanates. As compared to conventional heating, this new synthetic method saves energy, significantly reduces reaction time, and gets similar or improved yield. The reaction products have been fully characterized with (13)C, (1)H, and two-dimensional NMR spectroscopy. With suitable stoichiometry of starting CD and diisocyanate, the resulting CD polyurethane is organic-soluble and water-insoluble and is shown to remove Nile red dye and phenol from water. Possible applications include the removal of undesirable materials from process streams, toxic compounds from the environment, and encapsulation of color or fragrance molecules.

Epoxy monomers derived from tung oil fatty acids and its regulable thermosets cured in two synergistic ways.

A novel biobased epoxy monomer with conjugated double bonds, glycidyl ester of eleostearic acid (GEEA) was synthesized from tung oil fatty acids and characterized by (1)H and (13)C NMR. Differential scanning calorimeter analysis (DSC) and Fourier transform infrared spectroscopy (FT-IR) were utilized to investigate the curing process of GEEA with dienophiles and anhydrides. DSC indicated that GEEA could cross-link with both dienophiles and anhydrides through Diels-Alder reaction and epoxy/anhydride ring-opening reaction. Furthermore, Diels-Alder cross-link was much more active than the ring-opening of epoxy and anhydride in the curing process. FT-IR also revealed that GEEA successively reacted with dienophiles and anhydrides in both cross-linking methods. Dynamic mechanical analysis and mechanical tensile testing were used to study the thermal and mechanical properties of GEEA cured by maleic anhydride, nadic methyl anhydride and 1,1'-(methylenedi-4,1-phenylene)bismaleimide. Due to the independence between the curing agents, dienophile and anhydride, a series of thermosetting polymers with various properties could be obtained by adjusting the composition of these two curing agents.

Synthesis of soybean oil-based polymeric surfactants in supercritical carbon dioxide and investigation of their surface properties.

This paper reports the preparation of polymeric surfactants (HPSO) via a two-step synthetic procedure: polymerization of soybean oil (PSO) in supercritical carbon dioxide followed by hydrolysis of PSO (HPSO) with a base. HPSO was characterized and identified by using a combination of FTIR, (1)H NMR, (13)C NMR, and GPC methods. The effects of HPSO polysoaps on the surface tension of water and interfacial tension of water-hexadecane were investigated as a function of concentration of HPSO and counterion chemistry. HPSO polysoaps were effective at lowering the surface tension of water and the interfacial tension of water-hexadecane. They displayed minimum values of surface tension in the range of 20.5-39.6 dyn/cm at a concentration range of 3.2-32 µM and minimum values of interfacial tension in the range of 15.6-31.44 dyn/cm. The minimum surface and interfacial tension values were highly dependent on the nature of the counterion and increased in the order K(+) < Na(+) < TEA(+). These results suggested that a very low concentration of surfactant can be used to reduce the surface tension of water and interfacial tension of water-hexadecane. Water-hexadecane interfacial energy was also calculated from measured surface tension data using Antonoff, harmonic mean (HM), and geometric mean (GM) methods. Measured values agreed well with those calculated using the HM and GM. The HM method predicted slightly higher values than the GM method, but the Antonoff method did not agree with measured values.

Biosurfactants for microbubble preparation and application.

Biosurfactants can be classified by their chemical composition and their origin. This review briefly describes various classes of biosurfactants based on their origin and introduces a few of the most widely used biosurfactants. The current status and future trends in biosurfactant production are discussed, with an emphasis on those derived from plants. Following a brief introduction of the properties of microbubbles, recent progress in the application of microbubble technology to molecular imaging, wastewater treatment, and aerobic fermentation are presented. Several studies on the preparation, characterization and applications of biosurfactant-based microbubbles are reviewed.

Characterization of a soybean oil-based biosurfactant and evaluation of its ability to form microbubbles.

This paper characterizes the physico-chemical properties of the soybean oil-based polymeric surfactant, Palozengs R-004 (hereafter referred to as R-004). The surface activity of R-004 is comparable to the reported activities of biosurfactants produced by microorganisms and higher than some of the conventional synthetic surfactants. The surface tension of Milli-Q water was reduced to a minimum value of roughly 30mN/m at a concentration of about 0.07wt.%. R-004 exhibited a unique aggregation behavior: small aggregates (pre-micelles) were formed at very low concentrations. Zeta-potential measurements showed that the micelles of R-004 are negatively charged due to the presence of carboxylic groups. The ability of R-004 to form and stabilize microbubbles was evaluated and was found to be greatly affected by filtration while remaining independent of R-004 concentration over the concentration range studied (0.05-0.5wt.%). These results suggest that a very low level of surfactant can be used to produce microbubbles without affecting their properties. Our results suggest the possibility of using soybean oil-based surfactants to food, pharmaceutical, and cosmetic applications.

Lubricant base stock potential of chemically modified vegetable oils.

The environment must be protected against pollution caused by lubricants based on petroleum oils. The pollution problem is so severe that approximately 50% of all lubricants sold worldwide end up in the environment via volatility, spills, or total loss applications. This threat to the environment can be avoided by either preventing undesirable losses, reclaiming and recycling mineral oil lubricants, or using environmentally friendly lubricants. Vegetable oils are recognized as rapidly biodegradable and are thus promising candidates as base fluids in environment friendly lubricants. Lubricants based on vegetable oils display excellent tribological properties, high viscosity indices, and flash points. To compete with mineral-oil-based lubricants, some of their inherent disadvantages, such as poor oxidation and low-temperature stability, must be corrected. One way to address these problems is chemical modification of vegetable oils at the sites of unsaturation. After a one-step chemical modification, the chemically modified soybean oil derivatives were studied for thermo-oxidative stability using pressurized differential scanning calorimetry and a thin-film micro-oxidation test, low-temperature fluid properties using pour-point measurements, and friction-wear properties using four-ball and ball-on-disk configurations. The lubricants formulated with chemically modified soybean oil derivatives exhibit superior low-temperature flow properties, improved thermo-oxidative stability, and better friction and wear properties. The chemically modified soybean oil derivatives having diester substitution at the sites of unsaturation have potential in the formulation of industrial lubricants.

One-pot synthesis of chemically modified vegetable oils.

Vegetable oils are promising candidates as substitutes for petroleum base oils in lubricant applications, such as total loss lubrication, military applications, and outdoor activities. Although vegetable oils have some advantages, they also have poor oxidation and low temperature stability. One of the ways to address these issues is chemical modification of fatty acid chain of triglyceride. We report a one-pot synthesis of a novel class of chemically modified vegetable oils from epoxidized triacylglycerols and various anhydrides. In an anhydrous solvent, boron trifluoride etherate is used as catalyst to simultaneously open the oxirane ring and activate the anhydride. The reaction was monitored and products confirmed by NMR, FTIR, GPC, and TGA analysis. Experimental conditions were optimized for research quantity and laboratory scale-up (up to 4 lbs). The resultant acyl derivatives of vegetable oil, having diester substitution at the sites of unsaturation, have potential in formulation of industrial fluids such as hydraulic fluids, lubricants, and metal working fluids.

From oligomers to molecular giants of soybean oil in supercritical carbon dioxide medium: 1. Preparation of polymers with lower molecular weight from soybean oil.

Polymers with a low molecular weight derived from soybean oil have been prepared in a supercritical carbon dioxide medium by cationic polymerization. Boron trifluoride diethyl etherate was used as an initiator. Influences of polymerization temperature, amount of initiator, and carbon dioxide pressure on the molecular weight were investigated. It is shown that the higher polymerization temperature favors polymers with relatively higher molecular weights. Larger amounts of initiator also provide polymers with higher molecular weights. Higher pressure favors polymers with relatively higher molecular weights. The applications of these soy-based materials will be in the lubrication and hydraulic fluid areas.

A new polymer-lipid hybrid nanoparticle system increases cytotoxicity of doxorubicin against multidrug-resistant human breast cancer cells.

PURPOSE: This work is intended to develop and evaluate a new polymer-lipid hybrid nanoparticle system that can efficiently load and release water-soluble anticancer drug doxorubicin hydrochloride (Dox) and enhance Dox toxicity against multidrug-resistant (MDR) cancer cells. METHODS: Cationic Dox was complexed with a new soybean-oil-based anionic polymer and dispersed together with a lipid in water to form Dox-loaded solid lipid nanoparticles (Dox-SLNs). Drug loading and release properties were measured spectrophotometrically. The in vitro cytotoxicity of Dox-SLN and the excipients in an MDR human breast cancer cell line (MDA435/LCC6/MDR1) and its wild-type line were evaluated by trypan blue exclusion and clonogenic assays. Cellular uptake and retention of Dox were determined with a microplate fluorometer. RESULTS: Dox-SLNs were prepared with a drug encapsulation efficiency of 60-80% and a particle size range of 80-350 nm. About 50% of the loaded drug was released in the first few hours and an additional 10-20% in 2 weeks. Treatment of the MDR cells with Dox-SLN resulted in over 8-fold increase in cell kill when compared to Dox solution treatment at equivalent doses. The blank SLN and the excipients exhibited little cytotoxicity. The biological activity of the released Dox remained unchanged from fresh, free Dox. Cellular Dox uptake and retention by the MDR cells were both significantly enhanced (p < 0.05) when Dox was delivered in Dox-SLN form. CONCLUSIONS: The new polymer-lipid hybrid nanoparticle system is effective for delivery of Dox and enhances its efficacy against MDR breast cancer cells.

"Green" composites from renewable resources: preparation of epoxidized soybean oil and flax fiber composites.

In recent years there has been considerable interest in using natural plant fibers as reinforcements for plastics. The motivation includes cost, performance enhancement, weight reduction, and environment concerns. High performance flax fiber could potentially substitute for glass or carbon fibers as reinforcements for plastics. This study reports the "green" composites obtained from a mixture of epoxidized soybean oil and epoxy resin, 1,1,1-tris(p-hydroxyphenyl)ethane triglycidyl ether (THPE-GE), reinforced with flax fiber. The compression molding method is used for making the composites. Curing agents triethylenetetramine and diethylenetriamine provide better physical properties of the composites than Jeffamine agents D-230 and EDR-148. Both the flexural modulus and the tensile modulus of the composites increase as the amount of THPE-GE increases. The flexural modulus increased at a fiber content of <10 wt %, but there is a decrease beyond 10 wt %. The tensile modulus increases with fiber content until a maximum at 13.5 wt %, and then it decreases. The flax fiber length affected the mechanical properties of the composites: the longer the fiber length, the better are the mechanical properties observed.