Recipient Organization
UNIVERSITY OF GEORGIA
200 D.W. BROOKS DR
ATHENS,GA 30602-5016
Performing Department
College of Family & Consumer Sciences
Non Technical Summary
In the United States, widespread attention given to recyclability and environmentally friendly materials underscores growing interest in the development of sustainable, agricultural products with properties comparable to traditional petroleum-based coating/composites/plastics. Plant oils, as abundant, renewable resources, have the potential to replace petroleum as a chemical feedstock. Epoxidized camelina oil could make a good polymer coating with similar functional performance to petroleum resin when used for packaging, hard surface flooring, and binders in carpet matrices. The rationale underlying this project is that its successful completion will catalyze a vertical step in agricultural-based, value-added products. Our objectives include 1) developing expodized camelina oil coating formulations, evaluating their performance properties, cost effectiveness, and VOC generation, and comparing their properties to epoxidized soybean oil and petroleum-derived polyesters (polyolefins); and 2) investigate the specific, potential use of the epoxidized camelina oil resin in packaging, hard floor covering, and carpet binder applications. The proposed research will contribute in-depth understanding of the properties, performance, and cost competitiveness of epoxidized camelina oil formulations especially in flooring or packaging applications. The epoxidized camelina oil resins are expected to present commercial and environmental advantages, such as low cost, recyclability, carbon dioxide-neutrality, and biodegradability. Farmers, manufacturers, and consumers have potential to benefit from the creation of a market for sustainable, renewable resins made from camelina oil.
Animal Health Component
25%
Research Effort Categories
Basic
50%
Applied
25%
Developmental
25%
Goals / Objectives
This hatch research project addresses the National Institutes of Food and Agriculture's Critical Agricultural Materials initiative, which seeks "to develop and demonstrate industrial polymers that are manufactured from domestically produced agricultural materials and are of strategic and industrial importance to benefit the economy, defense, and general well-being of the nation" as well as the objectives #3.1(a) of the multistate project 1054, "Biobased Fibrous Materials and Cleaner Technologies for a Sustainable and Environmentally Responsible Textile Industry." Polymer resins and their innovative applications have increasing significance in the industrial and commercial fields. Polymer resins are generally synthesized from petroleum-based feedstock chemicals. However, plant oils, which are abundant, renewable resources, have the potential to replace or substitute for petroleum as a chemical feedstock (Can et al., 2006; Zhao et al., 2008). Although petroleum-based coating resins are durable and have barrier resistance properties, they can cause leaching and have organic volatiles (VOCs) with toxicity and/or environmental implications. Therefore, a need exists for fundamental research to develop coating formulations from sustainable resources which can provide consistent performance and have similar properties to petroleum-based coating materials.Epoxidized camelina oil could make a good polymer coating with similar functional performance to petroleum resin when used for packaging, hard surface flooring, and binders in carpet matrices. Camelina sativa is a fast-growing, low input plant that can be grown in poorer soils with minimal water, fertilizer, or pesticide requirements. Its tolerance for cold gives it potential for use as season rotational crop in Southeastern US and other temperate climates. Camelina oil is primarily used in the biodiesel industry. Camelina oil is a good alternative to other vegetable oils, such as soybean oil, because it will not compete with the food oil market. Finally, camelina oil is highly unsaturated which makes it an ideal candidate for epoxidation and chemical transformation into effective coatings and a competitive choice to soybean oil with its similar level of unsaturation (Abramovic and Abram, 2005; Gunstone (Ed.), 2011). The rationale underlying this project is that its successful completion will catalyze a vertical step in agricultural-based, value-added products. Goals / Objectives:Objective #1: Develop expodized camelina oil coating formulations, evaluate their performance properties, cost effectiveness, and VOC generation, and compare their properties to epoxidized soybean oil and petroleum-derived polyesters (polyolefins).Objective #2: Investigate the specific, potential use of the epoxidized camelina oil resin in packaging, hard floor covering, and carpet binder applications.
Project Methods
To achieve objectives #1 and #2, we plan to perform the following studies:Study 1: Camelina oils purchased through commercial sources will be analyzed for fatty-acid profile, water content and free fatty-acid content. High unsaturation in camelina oils due to the presence of fatty acids, such as linoleic and linolenic, make them appropriate for epoxidation. Unsaturated fatty acids have at least one double bond that can be easily epoxidized using hydrogen peroxide through hydrogen peroxide-catalyzed, acid-catalyzed, or chemoenzymatic processes. The first two methods are being used in industry, but have the following disadvantages: side reactions via oxirane opening leading to lower selectivity and corrosion problems due to the strong acid. However, this process can be made cleaner by using heterogeneous catalysts (e.g., ionic resins) or biocatalysts such as enzymes (e.g., lipase B of Candida antartica immobilized on a macroporous support). We will use both heterogeneous catalysts and enzymes to develop a method that is a solvent free and environmentally friendly method for production of epoxidized camelina oils. For instance, a known quantity of oil, acetic acid and heterogeneous catalyst will be mixed for 5 min, followed by dropwise addition of aqueous solution of H2O2. The reaction will be carried out for 5 h at 500 rpm. Then, the catalyst will be filtered out, followed by alkaline and water rinsing to remove free fatty acid and excess H2O2. The final organic phase will be dried and characterized for oxirane number, iodine value and selectivity. Processing variables, such as acetic acid:unsaturation ratio, H2O2:unsaturation ratio, concentration of H2O2, concentration of catalyst and temperature, will be optimized using a factorial design method. The response variable will be the degree of epoxidation (or oxirane number). The method stated above will be compared with the traditional industrial method using in situ peroxy acids catalyzed by a catalyst such as sulfuric acid. Oil, acetic acid and sulfuric acid will be added in a three neck flask with stirring for 30 min and aqueous H2O2 will be added dropwise over 30 min with continuous stirring. The resulting samples will be extracted using diethyl ether followed by rinsing with water.Study 2: Another important component of resin oil formulation is the curing/hardening agent. The synthesis of a novel curing agent, N-benzyl pyrazinium hexafluoroantimonate (BPH), to cure epoxidized oil resins will be adopted from a literature method by Park et al. (2004). The required amount of BPH curing agent will be dissolved in acetone, and then epoxidized oils will be added, stirred, and degassed for the molding process. Thermal experiments will be conducted in the differential scanning calorimetery and thermogravimetric analyzer and dynamic mechanical thermal analyzer to determine the curing/conversion extent of the resin and thermal transitions into the biothermoset matrix. This testing will help in optimizing the amount of curing hardener (0.5-5% of resin weight) used in the resin. In addition, thermal analyses will enable us to observe chemical changes such as oxidation and degradation. Further, dynamic mechanical analysis (DMA) of small, thermomechanically molded specimens will be tested for the mechanical performance over a temperature range spanning from subambient to 400 °F. Unmodified camelina oils along with curing agents will be used as controls. Factorial design method of statistics will be used to evaluate the impact of the following factors on the mechanical performance: level of oil epoxidation, amount of shear thinning agent and curing agent, and temperature of curing experienced during the extrusion coating process. In addition, the results will be interpreted using table of contrast coefficients to determine the most important factor. Resin Transfer Molding (RTM) injection and/or compression molding systems will be used for making lab-scale, coating plastic samples. Key physical and thermal properties of the developed coating material will be tested. Performance criteria of plastics, such as tensile strength and modulus (both quasi-static and dynamic) will be evaluated using standard test methods (e.g., ASTM or industry wide methods) that are prevalent in the packaging industries. Volatiles analysis will be conducted and compared to reported limit by static headspace using GC-MS instrumentation. The toxicity of the epoxidized camelina oil/BPH formulations will be tested for potential food packaging applications. Control samples of plastics from petroleum derived polyesters or polyolfeins will be produced for benchmarking. We will also compare epoxidized camelina oil with epoxidized soybean oil. At the conclusion of these studies, we expect to confirm the potential of camelina oil as a feedstock for polymer coatings and adhesives along with the appropriate formulation of these epoxidized oils to meet the desired performance characteristics of bioresins in packaging and other coating applications.Study #3: The presence of volatile organic compounds (VOCs) generated during thermal processing and use is an area of concern for food and non-food contact packaging and the carpet and flooring industries. The identification of volatile compounds and quantitative comparison of VOC's reduction for treated (both coated and laminated on lab-scale) and untreated samples will be performed via specialized gas chromatography and mass spectrometry (GC-MS) instrumentation. The results will be quantified to establish the efficacy of the camelina oil-based coating resins. This study is aimed at product development for resin formulations to be used in specific film applications, such as agricultural mulch films, food and non-food contact paper-based packaging, hard surface flooring coating and carpet backings. The coating resin formulations will be tested for their durability against environmental conditions and substrates of interest (interfacial stability). The base substrates under evaluation for this study are paperboard for packaging application, algae/LLDPE thermoplastic based mulch films for agricultural application (in collaboration with Algix, LLC), and hard surface flooring coatings and lamination of carpet backings for flooring applications. The coated and laminated substrates will be evaluated for their resistance to delamination at the interfacial region, volatiles, leaching, degradation, stiffening, and effects on tensile strength. The analysis conducted will include dynamic mechanical analysis (DMA), tensile strength, water stability, and scanning electron microscopy (SEM). Molecular level studies will be conducted using AFM to evaluate interfacial properties. The data from the performance analysis will be entered into a database to compare epoxidized camelina oil-based resin formulations on performance properties.ReferencesMeier, M. A. R., Metzger, J. O., and Schbert, U. S., Plant Oil Renewable Resources as Green Alternatives in Polymer Science, Chem. Soc. Rev., 36, 1788-, 2007.Park, S-. J., Jin, F-. L., and Lee, J-. R., Synthesis and Thermal Properties of Epoxidize Vegetable Oil, Macromol. Rapid Commun., 25, 724-, 2004.