No abstract

Rigid polyurethane (PU) foams were prepared using three North American seed oil starting materials. Polyol with terminal primary hydroxyl groups synthesized from canola oil by ozonolysis and hydrogenation based technology, commercially available soybean based polyol and crude castor oil were reacted with aromatic diphenylmethane diisocyanate to prepare the foams. Their physical and thermal properties were studied and compared using dynamic mechanical analysis and thermogravimetric analysis techniques, and their cellular structures were investigated by scanning electron microscope. The chemical diversity of the starting materials allowed the evaluation of the effect of dangling chain on the properties of the foams. The reactivity of soybean oil-derived polyols and of unrefined crude castor oil were found to be lower than that of the canola based polyol as shown by their processing parameters (cream, rising and gel times) and FTIR. Canola-PU foam demonstrated better compressive properties than Soybean-PU foam but less than Castor-PU foam. The differences in performance were found to be related to the differences in the number and position of OH-groups and dangling chains in the starting materials, and to the differences in cellular structure.

Polyols synthesized by ozonolysis and hydrogenation from canola oil were reacted with aliphatic 1,6-hexamethylene diisocyanates (HDI) to produce polyurethane (PU) elastomers. The properties of the materials were examined by dynamic mechanical analysis (DMA), thermomechanical analysis (TMA), modulated differential scanning calorimetry (MDSC), and thermogravimetric analysis (TGA), and measurements were taken of tensile properties. The effect of dangling chains on network properties was assessed. The formation of hydrogen bonds was observed by FTIR. The measured properties were found to be strongly dependent on processing-dependent factors such as the crosslinking density and the molar ratio of polyols to HDI component. The glass transition temperatures (T g ) of the elastomers were found to increase as the OH/NCO molar ratio decreased. With the same OH/NCO molar ratio, T g of canola-oil-based PU was higher than that of soybean-oil-based PU. The TGA thermographs showed two well-defined steps of degradation for all the elastomers. In the first step, up to 30% weight loss, the fastest rate of loss was found at 345°C for canola-oil-based PU while soybean-oilbased PU lost most of the weight in the second step. With the same OH/NCO molar ratio, the elastomers made from canola-oil-based polyol showed slightly higher Young's modulus and tensile strength.

Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) is a powerful new technique that will have a great impact on food analysis. This study demonstrates the applicability of MALDI-MS performed directly on an aqueous food extract for qualitative and quantitative analysis of food oligosaccharides. 2', 4',6'-Trihydroxyacetophenone was found to be the best matrix for analysis of oligosaccharides in the foods examined. The relationship between laser strength, resolution, and the response factors of individual oligosaccharides using MALDI-MS was investigated. A MALDI-MS method for quantitative analysis of fructooligosaccharides with standard addition of a pure fructooligosaccharide was developed. High performance anion exchange chromatography with pulsed amperometric detection was compared to MALDI-MS for the analysis of fructooligosaccharides. The fructooligosaccharide analyses were performed on red onions, shallots, and elephant garlic.