Surface Activity of Myristic Acid in the Poly(methyl methacrylate)/Supercritical Carbon Dioxide System

Abstract

To confirm the surface activity of myristic acid in the dispersion polymerization of vinyl monomers in scCO2, the interfacial tension (IFT) at the polymer/supercritical carbon dioxide (scCO2) interface has been measured. For the IFT measurements, a high-pressure pendant drop apparatus was constructed. The IFT data was obtained by the axisymmetric drop shape analysis of melt polymer droplets formed at the tip of a capillary. The reliability of the apparatus was confirmed by measuring the IFT of polystyrene (PS)/scCO2 and polypropylene (PP)/CO2 systems. The IFT of the poly(methyl methacrylate) (PMMA)/scCO2 system with and without myristic acid was also measured. The IFT decreased on addition of myristic acid. The magnitude of the IFT depression due to the myristic acid was comparable to that of PS/scCO2 systems with the block copolymer surfactant, PS-b-poly(fluorooctyl acrylate). The surface activity of the myristic acid was confirmed by the decrease of IFT.

Residual Monomer Reduction in Polymer Latex Products by Extraction with Supercritical Carbon Dioxide

“…The spreading coefficients are also collected in Table 1. The interfacial tension between CO 2 and polymer has been calculated by fitting data of Otake et al (2004), who correlated the CO 2 density to the interfacial tension between CO 2 and PS as well as between CO 2 and PMMA.…”

“…In case of PMMA, CO 2 was taken as phase 1 and PMMA as phase 3. (Kvamme et al, 2007 et al), between H 2 O and polymer (Sundberg et al, 1990, Webber et al, 1997 and between CO 2 and polymer (Otake et al, 2004). The spreading coefficients have been calculated with the Torza theory the polymer particles are partially wetted by the CO 2 and partially by the H 2 O, for PMMA.…”

“…Table 2 shows the interfacial tensions between H 2 O/SDS and CO 2 (Dhanuka et al, 2006), H 2 O/SDS and polymer (Sundberg et al, 1990, Sundberg andSundberg, 1993) and CO 2 and polymer, as well as the spreading coefficients. Otake et al (2004) reported about the interfacial tension at the CO 2 /polymer interface in the presence of tetradecanoic acid (MA), demonstrating the surface activity of carboxylic surfactants. At the same CO 2 density, the interfacial tension between CO 2 and polymer/MA is approximately half the value of the interfacial tension between CO 2 and polymer without surfactant.…”

“…(Dhanuka et al, 2006), between H 2 O/SDS and polymer (Sundberg et al, 1990, Sundberg andSundberg, 1993) and between CO 2 and polymer (Otake et al, 2004). The spreading coefficients have been calculated with the Torza theory The calculated spreading coefficients predict complete wetting of the polymer particles in CO 2 for both PS and PMMA.…”

“…The polymer particles have a diameter of 100 nm. (Kvamme et al, 2007 et al), between H 2 O and polymer (Sundberg et al, 1990, Webber et al, 1997 and between CO 2 and polymer (Otake et al, 2004). The equilibrium position of a polymer particle in a CO 2 -H 2 O system at 100 bar and 35 °C and the energy of the system have been calculated with the theory of Colver et al (2006).…”