STUDY OF BIOGELS OBTAINED BY IRRADIATION OF POLYMERS SOLUTIONS

PÉREZ R.D.; RUBIO M.; PÉREZ C.A.; AUSAR F.; BELTRAMO D.; BIANCO I.

Santiago

Congreso; II Simposio Binacional de Polímeros Argentino-Chileno ARCHIPOL II; 2003

Sociedad Chilena de Química-División de Macromoléculas.

During x-ray irradiation of aqueous solutions of polymers, chemical reactions are produced by means of reactive species such as hydrated electrons, hydroxyl radicals and hydrogen atoms. Crosslinking reactions result in linking polymer chains, thus they lead to the formation of macroscopic hydrogels. When radiation is used sterilization and "permanent" covalently crosslinked networks emerge as important characteristics for many applications. This work shows the capability of x-ray fluorescence spectrometry (XRF) excited by synchrotron radiation (SR) to study hydrogels. The goals of this work are: a- A new methodology for diffusion studies of low atomic weight molecules in hydrogels subjected by ionising radiation of a polymer solution. b- A direct measurement of the polymer concentration depth profile of the hydrogel in the vicinity of the air-gel interface by grazing exit (GE)XRF [1,2,3].Radiation synthesis of hydrogel: Hydrogels were prepared by irradiation of aqueous solution of quaternary ammonium substituted hydroxyethyl cellulose (QNHEC). CELQUAT SC240 (7.5%w/w) was irradiated in CEPROCOR into a N2 atmosphere absorbing a total dose of 25 kGy at 1.5 kGy/min dose rate.Diffusion