Partitioning of monobutyl itaconate and β‐carboxyethyl acrylate between organic and water phases

Abstract

Unsaturated carboxylic acids are usually used as functional monomers at low concentrations in emulsion polymerization to improve the colloidal stability and the mechanical properties of the films prepared from the corresponding latexes. These acids are distributed between the aqueous and organic phases to different extents due to their various water solubilities. The partitioning behavior of two new vinyl acids, monobutyl itaconate (MBI) and b-carboxyethyl acrylate (b-CEA), between n-butyl methacrylate (BMA) and the water phases was studied in this work. In addition, the partitioning of commonly used acrylic acid (AA) and methacrylic acid (MAA) was also determined as a benchmark. It was found that the partition coefficients (D) of MBI and b-CEA depended to a large extent on the acid concentration in the total comonomer mixture; the same trends were observed for AA and MAA. With the variation in monomer to water ratio (M/W), the D value of lipophilic acid MBI changed significantly, while for hydrophilic acid b-CEA, the D value changed very little. Furthermore, the values of the partition coefficient of MBI and b-CEA were very strong functions of pH, decreasing rapidly as the pH is increased. On the other hand, temperature has little effect on the partition coefficients for vinyl acids under typical emulsion polymerization reaction conditions.

Partitioning of 2-Carboxyethyl Acrylate between Water and Vinyl Monomer Phases Applied to Emulsion Polymerization: Comparisons with Hydroxy Acrylate and Other Vinyl Acid Functional Monomers

“…The differences may be attributed to the analytical methods used to measure the CEA distributions (HPLC analysis compared to water-phase acid–base titration). The minor differences in the experimental temperatures will not have created any significant problems in making this comparison of data sets between the results obtained here and those reported by Fang et al…”

“…The differences may be attributed to the analytical methods used to measure the CEA distributions (HPLC analysis compared to water-phase acid−base titration). The minor differences in the experimental temperatures will not have created any significant problems in making this comparison of data sets between the results obtained here and those reported by Fang et al 4 The dashed line in Figure 3 is the curve fit using eq 3 for the experimental C org,tot versus [HA W ] data. As can be seen here, the fit using eq 3 is excellent for this system.…”

“…Concentration of the CEA monomer in the nBMA phase ( C org,tot ) versus its undissociated form in the aqueous phase ([HA W ]) at equilibrium: (●) this work, 30 °C; (□) Fang et al, 25 °C. The dashed line is the fit from eq .…”

“… where C is the total concentration of the acid compound in the aqueous phase (mol/L). The p K a value for CEA is taken as 4.99 (at 25 °C). It should be noted that, without the addition of a buffer or base, the ionized portion of CEA is less than 2% when the acid level in the water is >0.05 mol/L.…”

UV/UV step-curing of optically clear acrylate adhesives for mobile devices

“…These have a high refractive index, which can contribute to clearer images on a display. Acrylic PSAs can be obtained through various polymerization processes such as the emulsion [7][8][9], solvent-type [10], water-borne [11], and radiation polymerization techniques [5]. However, much attention has recently been devoted to the use of more environmentally friendly processes, such as the ultraviolet (UV) technique.…”