Microscopic features of methacrylate polymers with zwitterionic pendant groups determined by various techniques

Abstract

The objective of this work was to determine microscopic structural features of three methacrylate polymers with different numbers of diethylene glycol residues and zwitterionic pendant groups. X‐ray diffraction, electron microscopy, and scanning probe microscopy techniques were employed. X‐ray data led to the adoption of a model made up of molecular aggregates forming lamellar domains, establishing in this way ordered characteristics of these kinds of polymers. Scanning electron microscopy images provided evidence of the occurrence of a lamellar structure forming the morphology of the polymers. This was corroborated by atomic force microscopy experiments. Transmission electron microscopy revealed that the lamellar aggregates conformed into clusters immersed in a polymeric matrix. From phase‐contrast images, information on the homogeneity of the composition at a molecular surface level was obtained. Then, the techniques provided evidence of the lamellar domain characteristics of the studied sulfobetaines. The crystallinity was a function of the number of ethoxy groups because as this number increased, the crystallinity became lower © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 1152–1160, 2005

Effect of the zwitterion structure on the thermo-responsive behaviour of poly(sulfobetaine methacrylates)

“…While polymers derived from monomers 5 have been studied occasionally, 29,45,46,48,50,[59][60][61] and polymers from monomer 4…”

Synthesis and Characterization of Zwitterionic Polymers with a Flexible Lateral Chain

“…PMBS-4/LiCl and PMBS-4/Li−triflate also showed a slight right-hand shift of the characteristic peak, similar to that found elsewhere in doped PEO systems with compounds containing Li + ions. The existence of a polymer−salt complex with stoichiometric ratios in polysulfobutylbetaines has been demonstrated by Cardoso et al using X-ray data. Therefore, we assume that LiCl, LiClO 4 , and Li−triflate were completely dissociated and incorporated into the polymer, as shown in its X-ray diffraction patterns (Figure B).…”

“…This morphology feature depended strongly on the number of ethoxy groups as reported in previous studies. 24 Since PMBS-4 has four ethylene glycol residues, its semicrystalline character is weak, as confirmed by the absence of ordered domains in the X-ray diffraction patterns shown in Figure 3A, hence providing information on the absence of domains made of correlated aggregate chains.…”

“…There is also evidence of strong dipole effects of the ionic side groups which allow the formation of complex salts up to stoichiometric ratios, resulting in the generation of a high concentration of ion carriers. It has been shown in previous papers 20,23,24 that polymethacrylates with zwitterionic pendant structures containing one, two, or three ethoxy groups in the side chain (labeled PMBS-1, PMBS-2, and PMBS-3) lead to the formation of aggregates around the ionic sites. Due to ion-ion interactions, the dielectric response starts around 200 °C up to decomposition temperature.…”

Ionic Conductivity of Polymer Electrolytes

“…The ability of a polymer material to dissolve salts can be studied with the dielectric parameters associated with relaxation processes in ion conducting polymers where the dielectric constant plays a fundamental role. [4,5] On the other hand, the synthesis, structure and dielectric properties of zwitterionic polymers have been extensively studied by Cardoso et al [6][7][8][9] and by Rozanski et al…”