Nitrogen and oxygen solubilities in vinyl monomer, cross-linker and ester, whose molecular structure is similar to that of methyl methacrylate

Nitrogen and oxygen solubilities were measured in two vinyl monomers, a cross-linker, and three esters, whose molecular structure is partly similar to that of methyl methacrylate (MMA), by using a synthetic apparatus up to 3.286 MPa at 303.20 +/- 0.02 K. The experimental data were compared with those of our previous report on MMA. The six compounds investigated were methyl acrylate (MA), vinyl acetate (VAc), ethylene glycol dimethacrylate (EGDMA), methyl acetate (MAc), methyl propionate (MPr), methyl isobutyrate (MiBu). EGDMA is composed of two MMA units with a tail-to-tail connection, and used as a cross-linker of MMA. VAc is a vinyl monomer with the same atomic composition as that of MA. All gas solubilities were linearly increased with the pressure, and the pressure dependencies followed Henry law. The order of nitrogen solubility was MiBu > MPr similar or equal to MMA-similar or equal to EGDMA > VAc > MAc similar or equal to MA, and the Henry constants ranged from 116.8 to 183.9 MPa. Similarly, that of oxygen solubilities was MiBu > EGDMA > MMA similar or equal to MPr similar or equal to VAc > MA similar or equal to MA & ccedil;, and the Henry constants ranged from 82.03 to 126.0 MPa. The experimental data were well correlated with the Peng-Robinson equation of state and its con-ventional mixing rules. Otherwise, as observed in MA and MAc, or in MMA and MPr, the gas solubilities in vinyl monomer were close to those in ester where vinyl group (H2C=C <) was replaced to methylene group (H2C <). The functional groups are thought to be a dominant factor to control the nitrogen and oxygen solubilities. The results suggested that the gas solubilities in vinyl monomers could be evaluated from those in the corresponding esters.

Automated summary

This study measured the solubilities of nitrogen and oxygen in two vinyl monomers, a cross-linker, and three esters. The experimental data were compared with those of methyl methacrylate (MMA) and correlated well with the Peng-Robinson equation of state. The functional groups were found to be the main factor controlling the solubilities of nitrogen and oxygen.