The large scale nitric acid oxidation of common sugars into their corresponding aldaric acids is being investigated as an important source of potentially useful components for industrial applications such as polymers. This thesis details the development of an Ion Chromatography (IC) method for the analysis of these oxidation mixtures and related samples from the work-up and purification processes. The method was developed for use with a Dionex ICS2000 IC system equipped with an AS11-HC column and utilising suppressed conductivity detection. IC proved to be a useful, versatile and straightforward method of studying the reactions and their products. The detected ions include but are not restricted to the anionic salt forms of: D-Glucaric acid, Xylaric acid, Mannaric acid, D-gluconic acid and both keto forms of the same, D-xylonic acid, D-mannonic acid, glycolic acid, oxalic acid, tartaric acid and tartronic acid. Nitrate from the nitric acid used in the oxidation is often observed. The results compare favorably to GC-MS and HPLC analysis of similar samples. An overview of the theory and operation of the instrument along with the method development and results from application to the oxidation mixtures and related samples are presented. As part of the investigation into the range of utility of IC for studying these reactions, a study was made of the retention behaviour of a large number of simple and low molecular weight (LMW) carboxylic acids eluted by the ion chromatography system in use. The results of this study are included with an explanation of the major factors affecting anion retention on the column

This thesis explored the development of a faster and more efficient means of qualitative and quantitative analysis of the products of the nitric acid oxidation of D-glucose and other simple sugars, for the Shafizadeh Rocky Mountain Center for Wood and Carbohydrate Chemistry. During the research, analysis was carried out based on previous work completed in a similar area using two Aminex HPX-87H+ cation-exchange columns at different temperatures, and plumbed in series. Standards were filtered and injected on to the columns, then eluted with 5 mM sulfuric acid. A total run time of 33 minutes enabled the elution of all products and by-products of the reaction. Retention times of standards and the use of spiking helped specify and quantify unknowns in samples from a series of oxidation reactions involving D-glucose and other aldoses. The PrevailTM Organic acid (OA) column was said to provide 'unsurpassed resolution of organic acids'. It was therefore investigated, and a method was developed and refined in order to optimise conditions enabling the column's use for the required analyses. The optimised parameters were established as: ambient temperature with an eluent of 10 mM KH2PO4 adjusted to a pH of 2.1 with phosphoric acid. The sample size was 5 uL with a flow rate of 0.3 mL/min, giving a total run time of approximately 13 minutes. The Aminex HPX-87H+ column method and the PrevailTM OA method were compared to determine the superior method for the analyses intended. While some improvements were made for detection in the PrevailTM OA method, results were not satisfactory. This was due in part to limits imposed on the PrevailTM OA column method, which prevented the use of gradient elution. The Aminex HPX-87H+ column method outlined herein provides superior resolution for the nitric acid oxidation of D-glucose to D-glucaric acid, and in conclusion it is suggested that the Aminex HPX-87H+ column method be used.

Pyrograf IIITM,/sup> fibers (PR-19-PS, Applied Sciences, Inc.) with 100-300 nm diameters and ~ 10-100 ìm lengths were used with a low viscosity aliphatic epoxy resin (Clearstream 9000, Clearstream Products, Inc.) to produce composites. The VGCFs were oxidized in 69-71 wt% nitric acid (115°C) for various times (10 min to 24 h) to modify the surface to enhance fiber/matrix adhesion. Remarkably, little fiber weight loss was detected even after 24 h of oxidation. Composites containing 19.2 volume percent (29.4 weight percent) VGCFs were prepared. Their flexural strengths and flexural moduli were obtained. The flexural strengths did not increase using oxidized VGCFs. Fiber surfaces were characterized using N2 BET, CO2 DR, XPS, SEM, TEM and base uptake measurements. Increasing the oxidation time produced only small initial increases in surface area up to a limit. Significant surface oxygen was present before oxidation and the amount increased initially, though not continuously, with nitric acid oxidation.