Abstract

SABINO, M.A; NUNEZ, O.  and  MULLER, A.J. EVIDENCIAS ESPECTROSCOPICAS DE LA DEGRADACIÓN HIDROLÍTICA DE LA POLI(p-DIOXANONA)). Rev. LatinAm. Met. Mat. [online]. 2002, vol.22, n.2, pp.40-51. ISSN 0255-6952.

In this work, the hydrolytic degradation of a biodegradable and bioabsorbable polymer, Poly(p-dioxanone) or PPDX, was studied. PPDX is an alifatic polyester-ether with potential for biomedical applications since its molecular structure and properties are adequate to be used as osteosynthesis material. PPDX degrades hydrolytically originating byproducts of low molecular weight that are non-toxic and that can be metabolize or bioabsorbed by the body. PPDX monofilaments were hydrolytically degraded in a phosphate buffer solution and in water at 37°C during 12 weeks, Fourier Transform Infrared Spectroscopy (FTIR) and Mass spectrometry (MS) were employed to characterize the degradation products. FTIR results showed that during the degradation period a decrease in the number of free O-H groups was recorded, a possible product of the association of these groups to those produced by degradation. It was also found that intermediary or complex structures were formed by group association where a contribution of the phosphate groups present in the hydrolysis medium is probable. Furthermore, as a consequence of the ester bond cleavage present in PPDX, a variation in the absorbance of bands associated to carbonyl groups are observed in view of the formation of carboxylic acid groups. These evidences were verified by Mass Spectrometry, whose results indicated that one of the degradation byproducts of PPDX is 2-hydroxy-etoxi-ethanoic acid.

Keywords : Poly(p-dioxanone),; degradation; hydrolysis; spectroscopy; biomaterials.