A method to prepare thermally stable resin fiber‐reinforced composites using solutions of appropriate monomers is described. Solutions containing a dimethyl ester of an aryl tetracarboxylic acid, the monomethyl ester of 5‐norbornene‐2,3‐dicarboxylic acid and an aryl diamine were used to impregnate graphite fibers. Composites fabricated from these prepregs exhibited excellent thermo‐oxidative stability and retention of mechanical properties at 600°F. These results compare favorably with those obtained from composites made from amide‐acid prepolymers capped with reactive alicyclic rings. Monomeric solutions provide excellent shelf life and improved solubility compared to amide‐acid prepolymer solutions.
Pulp mill wood residue was tested for its suitability as a filler for polyolefins. Samples of wood residue (residue from screened chips) were obtained from three southern kraft pulp mills. Screen analysis ofthe residues indicated that from 2 to 10 percent, by weight, passes a 48 mesh screen. The aspect, or length to diameter, ratio of the wood residue varied from 3 to over 19, compared to 2.5 for commercial wood flour. While the ash content of the residue was high, its lower cost and higher aspect ratio compared to wood floor indicated potential as a polymer filler. Composites of polyethylene and polystyrene with the wood residue were extruded and then injectionmolded into tensile bars. The results indicate little difference in extrusion torque, tensile modulus, or drop-ball impact strength between composites containing wood residue and wood flour.
Microwave and radio frequency heating techniques have proven to be suitable on the laboratory scale and for small scale field studies as energy sources for thermal processing of solvent contaminated hazardous waste and contaminated soils. The process described here is a technique that could be used to remove contaminates from soils or sludges on-site, collect the contaminate in an activated carbon absorption tower, and move the activated carbon off site for regeneration. The data presented show that destruction and removal efficiencies (DRE) of near 100% can be achieved for phenanthrene in simulated API separator sludge and 60% for pentachlorophenol in contaminated soil. A technique to enhance microwave absorption by the addition of carbon particles to the soil or sludge sample to be treated is discussed.4. recover the substrate from an exhaust gas; 5 . and dispose of the contaminate in an environmentallyWhen dealing with materials that are considered to be haz-substrate;acceptable manner.
The competitive adsorption of Hg, Cu, Ni, Cd, and Zn by softwood sawdust, corncobs, and ground scrap rubber was investigated. It is concluded that these materials which are abundant, widespread, and low cost, are potentially useful in removing various metal ions from wastewater solutions.
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