TY - JOUR
T1 - Kinetics of the aqueous-phase copolymerization of MAA and PEGMA macromonomer
T2 - Influence of monomer concentration and side chain length of PEGMA
AU - Emaldi, Iñaki
AU - Hamzehlou, Shaghayegh
AU - Sanchez-Dolado, Jorge
AU - Leiza, Jose R.
N1 - Publisher Copyright:
© 2017 by the authors.
PY - 2017/6/1
Y1 - 2017/6/1
N2 - An in situ nuclear magnetic resonance spectroscopy (NMR) technique is used to monitor the aqueous-phase copolymerization kinetics of methacrylic acid (MAA) and poly(ethylene glycol) methyl ether methacrylate (PEGMA) macromonomers. In particular, the study analyses the effect of the number of ethylene glycol (EG) groups along the lateral chains of PEGMA and is carried out under fully ionized conditions of MAA at different initial monomer ratios and initial overall monomer concentrations (5-20 wt % in aqueous solution). The composition drift with conversion indicates that PEGMA macromonomer is more reactive than MAA. Individual monomer consumption rates show that the rates of consumption of both monomers are not first order with respect to overall concentration of the monomer. The reactivity ratios estimated from the copolymerization kinetics reveal, that for the short PEGMA, the reactivity ratios rMAA and rPEGMA increase with the solids content (SC). A totally different trend is obtained for the longer PEGMA, whose reactivity ratio (rPEGMA23) decreases with solids content, whereas the reactivity ratio of MAA remains roughly constant.
AB - An in situ nuclear magnetic resonance spectroscopy (NMR) technique is used to monitor the aqueous-phase copolymerization kinetics of methacrylic acid (MAA) and poly(ethylene glycol) methyl ether methacrylate (PEGMA) macromonomers. In particular, the study analyses the effect of the number of ethylene glycol (EG) groups along the lateral chains of PEGMA and is carried out under fully ionized conditions of MAA at different initial monomer ratios and initial overall monomer concentrations (5-20 wt % in aqueous solution). The composition drift with conversion indicates that PEGMA macromonomer is more reactive than MAA. Individual monomer consumption rates show that the rates of consumption of both monomers are not first order with respect to overall concentration of the monomer. The reactivity ratios estimated from the copolymerization kinetics reveal, that for the short PEGMA, the reactivity ratios rMAA and rPEGMA increase with the solids content (SC). A totally different trend is obtained for the longer PEGMA, whose reactivity ratio (rPEGMA23) decreases with solids content, whereas the reactivity ratio of MAA remains roughly constant.
KW - Aqueous-phase copolymerization
KW - Ionization degree
KW - Polyethylene glycol methacrylate monomers
KW - Reactivity ratios
KW - Solids content
UR - http://www.scopus.com/inward/record.url?scp=85034260976&partnerID=8YFLogxK
U2 - 10.3390/pr5020019
DO - 10.3390/pr5020019
M3 - Article
AN - SCOPUS:85034260976
SN - 2227-9717
VL - 5
JO - Processes
JF - Processes
IS - 2
M1 - 19
ER -