Ronald Holser

Boron trifluoride catalyzed ring-opening polymerization of epoxidized soybean oil in liquid carbon dioxide

Ring-opening polymerization of epoxidized soybean oil (ESO) catalyzed by boron trifluoride diethyl etherate (BF3·OEt2), in liquid carbon dioxide, was conducted in an effort to develop useful biobased biodegradable polymers. The resulting polymers (RPESO) were characterized by FTIR spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), 1H NMR, 13C NMR, solid state 13C NMR spectroscopies and gel permeation chromatography (GPC). The results indicated that ring-opening polymerization of ESO occurred at mild conditions, such as at room temperature, and a subcritical CO2 pressure of 65.5 bar. The formed RPESO materials were highly crosslinked polymers. The glass transition temperatures of these polymers ranged from −11.9 °C to −24.1 °C. TGA results showed that the RPESO polymers were thermally stable at temperatures lower than 200 °C and significant decomposition mainly occurred above 340 °C.

Principal Component Analysis of Phenolic Acid Spectra

Phenolic acids are common plant metabolites that exhibit bioactive properties and have applications in functional food and animal feed formulations. The ultraviolet (UV) and infrared (IR) spectra of four closely related phenolic acid structures were evaluated by principal component analysis (PCA) to develop spectral models for their rapid detection. Results demonstrated that UV and IR spectra could discriminate between each of the phenolic acids in overall models. Calculation of model scores and loadings showed that derivative UV spectra accounted for 99% variation with 2 principal components (PC) while derivative IR spectra required 3 PCs. Individual PCA models were developed for ferulic acid and p-coumaric acid using derivative UV spectra for detection and classification by soft independent modeling of class analogy (SIMCA). The application of this spectral technique as a classification model is expected to promote the use of agricultural residues as a source of these phenolic compounds.

Encapsulation of Polyunsaturated Fatty Acid Esters with Solid Lipid Particles

Abstract: Encapsulation of structurally sensitive compounds within a solid lipid matrix provides a barrier to prooxidant compounds and effectively limits the extent of oxidative degradation. This offers a simple approach to preserve the bioactivity of labile structures. The technology was developed for cosmetic and pharmaceutical products but may be applied to additives used in food and feed formulations. The encapsulation of docosahexaenoic acid (DHA) and -linolenic acid (ALA) was examined as model compounds of current interest in functional foods and feeds. Solid lipid particles were prepared from triglycerides containing saturated and unsaturated fatty acids and evaluated by differential scanning calorimetry. The thermal characteristics of the lipids used to form the particle were related to molecular structure and could be adjusted by selection of the appropriate component fatty acids. Encapsulation by solid lipid particles provides a method to inhibit oxidation and improve shelf life of products formulated with DHA and ALA.

Capacitance Sensing of Moisture Content in Fuel Wood Chips

Moisture content of wood chips is an important factor to be known in their utilization as a biomass material. Several moisture measuring instruments are available in the market, but for most of these instruments, some sort of sample preparation is needed that involves sizing, grinding, and weighing. The samples in this process are usually destroyed, and the measurement involves considerable time and labor. The standard methods of oven drying and Karl Fisher also fall in the destructive and laborious category. In this paper, estimation of moisture content of hardwood chips, from the measurement of certain electrical properties of a parallel-plate capacitor, holding the samples of these materials between them at two radio frequencies, is presented. The wood chip samples tested were in the moisture range of 3%-50%. The standard error of prediction was 2.0, and the prediction accuracies were better for the samples with moisture contents below 25%. The construction and performance of a prototype moisture sensing instrument working on these principles is briefly described. This method being nondestructive and rapid would be useful in the biofuel industry.

Use of polyunsaturated Fatty Acids with α-Tocopherol in poultry Feeds

The ability of α-tocopherol to prevent the degradation of the polyunsaturated fatty acids, docosahexaenoic acid (DHA) and linolenic acid (ALA) at elevated temperature was investigated in a series of laboratory experiments. DHA is known to promote nervous system function and health, however, DHA and other highly unsaturated fatty compounds are readily oxidized with loss of bioactivity. Mixtures of DHA or ALA and α-tocopherol were incubated at 70 °C. Samples of these mixtures were analyzed by gas chromatography. After 72 hours at 70 °C mixtures with 0.25 mg α-tocopherol/mg retained 79.6% of the initial amount of DHA and 94.2% of the ALA. When α-tocopherol was present at 2.5 mg/mg the amount of DHA decreased to 62.5% and ALA decreased to 87.4%. Control samples that did not contain α-tocopherol retained 43% DHA and 52.6% ALA. These results indicate that α-tocopherol can limit the degradation of these polyunsaturated fatty acids at elevated temperature. However, the greatest protective effect was not obtained with the highest level of α-tocopherol. This relationship needs to be considered when formulating feeds where elevated process temperatures are likely to occur.

Biocomposites Prepared from Fiber Processing Waste and Glycerol Polyesters

Biocomposites were prepared by the addition of flax fiber processing waste to glycerol and adipic acid mixtures. The processing waste consisted of fiber, cuticle, and shive fragments generated during the commercial cleaning of retted flax bast fibers. These waste materials were added at 1, 3, or 5 wt% levels to polymer formulations containing either 10% or 20% molar excess acid. The solids were randomly mixed with the polymer and cured at 125˚C. Tensile properties of the resulting biocomposites were determined by ASTM D 3039/D 3039M. Biocomposites formulated with 20% excess acid showed an increase in Youngs modulus from 1.44 MPa to 8.56 MPa and ultimate load from 4.50 N to 8.77 N with 5 wt% added solids compared to control specimens. The percent strain values for these samples showed a corresponding decrease as the level of added solids increased.