The UV/H2O2 - photodegradation of poly(ethyleneglycol) and model compounds

Author(s)

Santos, Lais C. ^[1] ; Poli, Alessandra L. ^[1] ; Cavalheiro, Carla C. S. ^[1] ; Neumann, Miguel G. ^[1]

Affiliation

^[1] Univ Sao Paulo, Inst Quim, BR-13560970 Sao Carlos, SP - Brazil

• Document type: Journal article
• Source: Journal of the Brazilian Chemical Society; v. 20, n. 8, p. 1467-1472, 2009.
• Web of Science Citations: 20

Abstract

The general mechanism for the photodegradation of polyethyleneglycol (PEG) by H2O2/UV was determined studying the photooxidation of small model molecules, like low molecular weight ethyleneglycols (tetra-, tri-, di-, and ethyleneglycol). After 30 min of irradiation the average molar mass (Mw) of the degradated PEG, analysed by GPC, fall to half of its initial value, with a concomitant increase in polydispersitivity and number of average chain scission (S), characterizing a random chain scission process yielding oligomers and smaller size ethyleneglycols. HPLC analysis of the photodegradation of the model ethyleneglycols proved that the oxidation mechanism involved consecutive reactions, where the larger ethyleneglycols gave rise, successively, to smaller ones. The photodegradation of ethyleneglycol lead to the formation of low molecular weight carboxylic acids, like glycolic, oxalic and formic acids. (AU)

• FAPESP's process: 03/07770-4 - Interactions of visible light with polymers: photopolymerization and photodegradation
• Grantee: MIGUEL GUILLERMO NEUMANN
• Support Opportunities: Research Projects - Thematic Grants