Aspects of the Safe Storage of Acrylic Monomers: Kinetics of the Oxygen Consumption

摘要

Safe storage and handling of acrylic monomers assumes detailed knowledge about possible reactions and influence parameters on the radical polymerization. An investigation was made in order to predict the stability of the monomers by quantifying the oxygen consumption due to the inhibition process for different influence parameters. The oxygen consumption was investigated for acrylic and methacrylic acid without inhibitor as well as in the presence of p-methoxyphenol (package inhibitor) and phenothiazine (process inhibitor) in the temperature range from 40 to 80 ℃. The addition of stabilizer lowers the oxygen consumption in the monomers, which results in a higher stability. The oxygen consumption rates for unstabilized (up to 60 ℃) and p-methoxyphenol-stabilized monomers fit the Arrhenius equation and can therefore be extrapolated to other temperatures. The stability of the monomers at higher temperatures can be predicted with the help of the oxygen consumption rates (not for phenothiazine). At lower temperatures, slow polymerization rates can extend the stability of the monomer beyond the time of oxygen inhibition.