Alfred A. Donatelli

Fluorescein and Poly(Ethylene Oxide) Hose Stream Additives for Improved Firefighting Effectiveness

A novel technique has been developed to accurately monitor levels of hose stream additives by adding a fluorescein tracer. A fluorescent agent system is proposed to control and monitor additives into hose streams. Fluorescent water streams also have the advantage of improved nighttime and low-light visibility.Poly(ethylene oxide) (PEO) was shown in the 1960s to be very effective in fire hose streams, providing dramatic increases in hose stream pressure, reach, and volume. As is discussed in this paper, however, PEO fell into disrepute for firefighting operations. A reexamination strongly indicates the inaccuracy of previous misperceptions and indicates that PEO deserves reconsideration as being potentially powerful for greatly enhanced petroleum, ordnance, high-rise and impeded access firefighting, in which increased stand-off distances are desirable.

The Effects of Evaporation and Condensation on an Absorption Process

Research was conducted to investigate the qualitative effects of evaporation and condensation on an absorption process. Individual droplets of distilled water of known weight and temperature were dropped through a counter-flowing gas mixture that contained a known concentration of ammonia and water vapor. Variations in evaporation and condensation rates were realized by varying droplet temperature and the water vapor content of the gas mixture. The collected droplets were analyzed for ammonia concentration and the qualitative effects established. The experimental results indicate that absorption rates increase with an increase in condensation and decrease with an increase in evaporation rate.

Fracture Toughness of Elastomer Modified Epoxy Adhesives

Elastomer modification is an effective way of toughening glassy epoxy resins. The toughening mechanisms of phase separation and gellation have been studied extensively. This paper reports the effects of carboxyl terminated acrylonitrile rubber on several single component epoxy adhesives, based on Epon 828 and cured with dicyandiamide. Variables include accelerator type and level, cure temperature and elastomer level. There is an optimum amount of rubber which may be added to each system to yield maximum shear strength. Peel strength is maximized in two regions. Rapid gellation of these adhesives may be detrimental to the phase separation and chain extension mechanism and thereby cause lowering of fracture toughness and strength properties.

Poly(Butadiene-Co-Styrene)/Polystyrene IPN’s, Semi-IPN’s and Graft Copolymers: Staining Behavior and Morphology

Since the synthesis of interpenetrating polymer networks (IPN’s) in this laboratory in 1967,(1) the existence and importance of two-phase morphologies have become increasingly apparent.(2,3) A close relationship to graft copolymers has also been recognized. The research reported here is the first systematic study of the morphological relationships between IPN’s and graft copolymers of the solution graft type. Because of the critical role of staining in revealing morphologies on the 100 A scale, we have studied the kinetics of OsO4 staining as well.