| 摘要 |
<p>Methanol, ethanol, and methanol/ethanol deicers are formulated to contain additives which inhibit evaporation of the deicers during application, thereby dramatically reducing evaporative losses. These additives also function to reduce flammability of accidental spills during transportation and handling. The additives consist of long chain aliphatic alcohols which are economical, effective at low concentrations, relatively non-corrosive, and relatively harmless to asphalt and Portland cement concrete pavements. The inhibiting film which forms at the air/solution interface has been shown to be formed through absorption of atmospheric moisture into the deicer. Films are, surprisingly, formed when the inhibitor is at concentrations far below the equilibrium saturation concentration in the original test solution, at test temperature. Addition of a controlled amount of water to the inhibited alcohol formulations desirably increases their density or specific gravity, and reduces the concentration of additive required to effectively inhibit evaporation losses of applied deicer. The added water also increases the solubility of added known deicers, e.g. urea in the formulation. The function of an added deicer or freezing point depressant is to further increase the density or specific gravity of the formulation. Quite unexpectedly, however, it has been discovered that addition of a deicer such as urea to the inhibited methanol dramatically reduces methanol evaporation rate, i.e. reduces it far below the level which would have normally been anticipated through the application of Raoult's Law. Preferred embodiment deicer formulation of this invention have exhibited virtually zero evaporation rate immediately upon pouring the deicer into shallow test vessels. Both magnetically-stirred and quiescent inhibited test liquids exhibit dramatically reduced evaporation rates. Deicers should therefore be effective on undisturbed and on trafficked roadways. The novel evaporation-inhibition feature allows for the first time consideration for commercial use of economical alcohols possessing low osmolar weight and desirably low eutectic temperatures in the water/ice system. <IMAGE></p> |
