Abstract

DALLOS, Leidy J.; MANZO, Rubén H.  and  BAENA, Yolima. FTIR and DSC analysis of polyelectrolyte complexes between Eudragit^® E100 and benzoic acid as evidence of hydrolysis of the polymer ester groups. Rev. colomb. cienc. quim. farm. [online]. 2019, vol.48, n.3, pp.700-721.  Epub Nov 04, 2020. ISSN 0034-7418.  https://doi.org/10.15446/rcciquifa.v48n3.84987.

Polyelectrolyte complexes obtention between Eudragit® E100 (cationic polymer) and anionic molecules with additional neutralization of inorganic acids is a common practice in the development of these systems. In the present work the addition of strong acid effect on polymer structure was evaluated through FTIR and DSC analysis of a set of ten complexes with different composition (between Eudragit® E100 and benzoic acid) and four ionomers (without the preservative) obtained by solvent evaporation technique.

Results demonstrated the complexes and ionomers formation. FTIR spectra revealed direct relationship between polymer ester groups hydrolysis reaction and the amount of HCl added. The thermograms, on the other hand, evidenced the existence of a reaction in the polyelectrolyte, which was favored in those compositions with more hydrolysis process. The degradation reaction described in this study should be taken into consideration in future research, since its occurrence could have implications in variables evaluated in this type of systems.

Keywords : Eudragit^® E100; hydrolysis; benzoic acid.

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