Patrick Joseph Mccloskey

Reductive Dechlorination of Chlorinated Aromatics

Abstract A practical method has been found for the reduction of PCBs and chlorinated benzenes in a nonpolar solvent with formic acid, water, Pd/C and sodium carbonate. This reductive dechlorination can be run under atmospheric pressure and relatively mild conditions.

Determination of phosphorus in polymeric systems using an ashing procedure and inductively coupled plasma atomic emission spectrometry

Phosphorus in different forms is used in a variety of applications (catalysts, thermal stabilizers, flame retardants) in polymeric formulations. It is important to be able to determine its concentration in raw materials, intermediates and final products. The challenge of measuring low concentrations of P, combined with the volatility of the organic phosphorus compounds, has been solved through a novel analytical procedure with a method detection limit of 0.4 µg g−1 P (10σ). The volatilization of organic P compounds was prevented by pre-oxidation with periodic acid, which allows ashing in the presence of magnesium acetate while maximizing the weight to final volume ratio. Using factorial design of experiments, experimental factors including ashing temperature, time, and the amount of the reagents were optimized with respect to accuracy and precision of the technique. The influence of Ti when present in the samples was eliminated by complexing it with H2O2. Additional pre-treatment with NH4OH was found to improve recovery for some reactive samples. Comparison with other established methods was carried out and is discussed.

Activated carbonates: enabling the synthesis of differentiated polycarbonate resins via melt transcarbonation

Activated carbonates facilitate the preparation of polycarbonates based on monomers that are unsuitable for traditional melt polymerization at high temperatures. Bis(methyl salicyl) carbonate (BMSC) clearly shows reactivity benefits over diphenyl carbonate in melt polymerization reactions, resulting in shorter reaction times and reduced heat exposure during polymerization. The increased reactivity enables the melt polymerization of a wide range of monomers, as demonstrated by two examples using volatile resorcinol and sterically hindered tert-butyl hydroquinone as monomers in the preparation of (co)polycarbonates.

Recent Progress on Micro-holographic Data

Advances in micro-holographic materials and systems are presented. New materials show improved index change (10x) and sensitivity (100x) at >3x lower intensity vs. previously reported. Experimental results supporting single-sided optical drive concept is presented.

Determination of Quantitative Structure–Property Relationships of Solvent Resistance of Polycarbonate Copolymers Using a Resonant Multisensor System

In sensor and microfluidic applications, the need is to have an adequate solvent resistance of polymers to prevent degradation of the substrate surface upon deposition of sensor formilations, to prevent contamination of the solvent-containing sensor formulations or contamination of organic liquid reactions in microfluidic channels. Unfortunately, no comprehensive quantitative reference solubility data of unstressed copolymers is available to date. In this study, we evaluate solvent-resistance of several polycarbonate copolymers prepared from the reaction of hydroquinone (HQ), resorcinol (RS), and bisphenol A (BPA). Our high-throughput polymer evaluation approach permitted the construction of detailed solvent-resistance maps, the development of quantitative structure–property relationships for BPA-HQ-RS copolymers and provided new knowledge for the further development of the polymeric sensor and microfluidic components.