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The objective of this project was to examine the chemical and/or physical bonds created in the process of encapsulating/fixing AAP-type sludges. Typical sludge compositions were selected for detailed study on review of sludges generated during wastewater treatment and related operations at 22 Army facilities. Candidate fixatives included polysilicates, amine-cured polyepoxides and polysulfides. A limited study was also conducted using ion-exchange resins of the non-ionic type for sludges containing TNT and rdx; and cationic exchangers with specific chemically reactive groups for sludges containing heavy metals. The measure of effectiveness of the AAP sludge-fixative combination was EPA's EP Toxicity Test. Instrumentation characterization methods included optical microscopy, infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray analysis, and X-ray diffraction. Polysilicates were found to fix heavy metals as a consequence of the highly alkaline-buffered media they provide. Nitrocellulose was observed to react with epoxy ingredients with the possible removal of nitrato groups. Studies with polysulfides and ion-exchange resins were encouraging, resulting in chemically fixed sludges of high contaminant density and resistance to leaching.

This report provides method, materials evaluations and engineering for managing wastes hazardous to man and other life by localization employing an organic, polymeric cementing and encapsulating process (TRW process). Specimens, of cubic dimensions three inches on edge, of wastes cemented with 3 to 4% by weight polybutadiene binder and encapsulated by 1/4 inch polyethylene jackets, were fabricated with selected wastes and subjected to exacting leaching conditions and mechanical testing. They were found to exhibit excellent retention of contaminants in leaching by a broad spectrum of aqueous solutions and to withstand degradation under high compressive and impact mechanical forces.

This final report describes the work performed to advance the state-of-the-art of resin matrices required for improved ablative materials for use with high energy fluorine-containing liquid propellant systems. This was accomplished through a comprehensive theoretical and experimental study which (a) defined critical parameters controlling the effectiveness of resins in ablative systems, (b) synthesized new resins and determined critical properties of new and modified resins, and (c) recommended resins for future use. The critical resin properties which influence the effectiveness of ablative composites were determined analytically in order that criteria could be established for the synthesis and property testing of new and modified resins. As a result of these studies, criteria were provided for directing and selecting promising areas of resin synthesis and modification. Several new polymer systems with improved properties were proposed, evaluated and recommended for future study. Poly (cyclized 1, 2 polybutadiene) tolylurethane ladder polymers, poly alkaline earth metal acrylates, phosphate bonded oxides, modified polyimides and several other organic and inorganic systems were conceived and/or evaluated during this program to meet the property requirements identified analytically.

This final report describes the work performed to advance the state of the art of resin matrices required for improved ablative materials for use with high energy fluorine containing liquid propellant systems. This experimental program was a continuation of a previously reported effort (NASA CR-54471) and consisted of a systematic materials development effort of resin synthesis and property determination of new and previously identified resin systems, optimization of composite processing parameters and fabrication and use testing of candidate ablative composites. Two new high char forming polymer systems were synthesized, fabricated and evaluated in composite form for ablative use effectiveness. These aromatic/heterocyclic polymer systems were designed to be processed readily with the evolution of minimum quantity of volatile matter during cure. As a consequence, low void, high strength composites were prepared which exhibited ablative performance (combination of dimensional stability, weight retention and resistance to thermal shock) superior to commercially available ablative materials when tested in a FLOX/methane torch combustion environment. Tested composites were prepared using Refrasil, graphite and carbon cloth and titanium diboride fibrous reinforcements.

This report describes the preparation of Pyrrone laminates, from a sulfone dianhydride, which would be suitable for long-term exposure to extreme thermal and oxidative environments. The work was divided into three principal tasks: (1) monomer synthesis, (2) polymer synthesis and characterization, and (3) laminate processing and evaluation. Pyrrone resins were prepared from bis (3, 4-dicarboxyphenoxyphenyl) sulfone dianhydride and 3, 3'-diaminobenzidine. Suitable conditions were determined for preparing laminates from completely soluble Pyrrone precursors. The laminates, which were made under relatively mild processing conditions, had medium void content and had mechanical properties similar to other state of the art condensation polymers. Laminates were subjected to long term exposure in forced air environments representing extreme end use thermo-oxidative conditions. The Pyrrone composites demonstrated resistance to the oxidative environment, but gradually succumbed under the conditions employed. The aging data were used to predict useful life durations for specimens tested. The experimental feasibility study has given results that demonstrate several interesting features of the Pyrrone films and laminates prepared from bis(3, 4-dicarboxyphenoxyphenyl) sulfone dianhydride and 3, 3'-diaminobenzidine. This resin gave neat resin and composite properties similar to or exceeding those published for state of the art Pyrrone polymer systems.