Summary Research into elucidation of the decomposition mechanism of phenolic resin is being undertaken at the United Kingdom Defence Science and Technology Laboratory. In spite of the widespread use of phenolic resins the underlying decomposition mechanism is not yet fully understood. Central to understanding the mechanism is knowledge of the chemical products formed during the decomposition process and their respective quantities. Pyrolysis‐gas chromatography‐mass spectrometry and pyrolysis‐Fourier transform infrared spectroscopy techniques have been developed to quantify the volatile organic compounds (VOCs), the permanent gases and water generated from the thermal decomposition of a phenolic resin. The VOCs and permanent gases that are produced during pyrolysis of phenolic resin have been identified. Quantitative analysis of the pyrolysis products has been undertaken and the initial results indicate that heating rate affects the composition of the products. Elemental analysis of the residue has been performed.

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Objective: The purpose of this case study is to describe the presentation of a patient with plasmacytoma. Clinical Features: A 49-year-old man presented with progressive neck pain, stiffness, and dysphagia to a chiropractic office. A radiograph indicated a plasmacytoma at C3 vertebral body. The lesion was expansile and caused a mass effect anteriorly on the esophagus and posteriorly on the spinal cord. Neurologic compromise was noted with fasciculations and hypesthesia in the right forearm. The patient was referred to a neurosurgeon. Intervention and Outcome: Surgical resection of the tumor was performed with a vertebral body spacer and surrounding titanium cage. Bony fusion was initiated by inserting bone grafts from the iliac crests into the titanium cage. Additional laboratory analysis and advanced imaging confirmed that the plasmacytoma had progressed to multiple myeloma and radiation and chemotherapy were also necessary. Conclusion: A chiropractor recognized a large, expansile plasmacytoma in the C3 vertebral body and referred the patient for surgical care. This case suggests that all practitioners of manual medicine should provide a careful analysis of the patient's clinical presentation and, if clinically warranted, radiographic examination to determine neck or back pain is due to an underlying malignant condition. (J Chiropr Med 2017;16:170-174)

UV irradiation at 77 K of arenediazonium salts substituted at the 4 position by dialkylamino groups yields ESR spectra comprised of three principal, broad peaks at ca. 800, 1500, and 4400 G, together with a resonance at g -2.0. The low-and high-field absorptions are assigned to the aryl cation, Ar+, which appears to be stabilized in its triplet configuration by the -NR2 group in accordance with recent ab initio calculations. The D parameter for these unusual triplet states is ca. 0.24 cm-l, indicating a high K spin density on C1. The triplet states were produced from powders and solutions in both polymer films and a 9 M LiCl aqueous glass, and constitute irrefutable evidence for the existence of these carbonium ions.The aryl cation Ar+ has long been regardedZa as the probable key intermediate in both the thermal2" and photochemicalZb decomposition of arenediazonium salts in aqueous solution:L o r hw ArN*+ -Ar+ + Nz While there have been suggestions (summarized in Zollinger's review2c) that the departure of N2 may coincide with arrival of a water molecule or other n~cleophile,~ this view has been strongly c o n t e~t e d .~~.~ The extremely high reactivity of the supposed Ar+ is implied both by its lack of selectivity toward nucleophile^^^ and its apparent ability to reverse reaction 1 as evinced both by scrambling of I5N-l4N in partially decomposed ArN*+X-and by incorporation of N * when dediazoniation is carried out under high pressures of n i t r~g e n .~ The recent intensified interest in Ar+ has focused upon (1) its detection and role as an intermediate in gas-phase studies involving mass spectrometry,6a ion cyclotron resonance,6b and crossed molecular beams,6c and (2) theoretical approaches to its structure, dimensions, and spin m~l t i p l i c i t y .~~~ In the latter context, Taft's early proposal9 (modified by AbramovitchIo) that Ar+ is a triplet ground state, based on anomalously large accelerating effects of substituent groups such as m-OMe on the thermal decomposition of ArN*+ (an argument since criticized4"), has been developed by several groups using semiempirical m e t h o d~~~,~ and most recently by a b initio calculations of Pople etThe latter approach suggests that of the two alternative electronic configurations for Ar+, the "Taft configuration" ( x )~ (sp2)I is especially stabilized8c by a p-NH2 group; otherwise the ( T )~ (sp*)O configuration, albeit highly distorted with L C~C I C~ -145O, is the more stable form by a considerable margin (e.g., 20.1 kcal mol-] for C6Hs+ itself).8b Other "triplet-stabilizing'' influences are substitution a t the ortho positions (by NH2 or OH) and a t the para position by OH (although only the latter feature gave per se a resultant triplet ground state apart from p-NH2, and then only as a small difference between two large figures). Another group" has argued that the greater selectivity of p-O2NC6H4+ toward attack on arenes (compared with C6H5+) is best understood in terms of both species existing as triplets, with the NO2 substituent exercising additional stabi...

Different computational techniques have been used to study phenolic resins with the objective of developing methods for predicting the high temperature physics and chemistry of resins with sufficient accuracy to produce data for the engineering modelling codes used to design thermal protection systems. The building of structural models of the resin using MOPAC ® and the validation of these models through comparison of measured and calculated thermochemical, structural and spectroscopic properties is described. Using these structural models, high temperature resin chemistry is simulated using the reactive molecular dynamics programme ReaxFF. Preliminary results are presented for early stage gas evolution and final stage char production during pyrolysis.