Na. Andreucetti et al., EFFECT OF THE PHENOLIC ANTIOXIDANTS ON THE STRUCTURE OF GAMMA-IRRADIATED MODEL POLYETHYLENE, Radiation physics and chemistry (1993), 52(1-6), 1998, pp. 177-182
Citations number
13
Categorie Soggetti
Nuclear Sciences & Tecnology","Chemistry Physical","Physics, Atomic, Molecular & Chemical
High energy radiation has been successfully employed to modify the che
mical structure of commercial polymers. It induces at least two types
of reaction in polyethylene: crosslinking and chain scission. In addit
ion the efficiency of the radio-induced reactions can be affected by t
he presence of antioxidants. The purpose of this work is to study the
effect of the irradiation on a model polyethylene containing a phenoli
c type antioxidant. Samples containing 0.1% and 1% by weight of Irgano
x 1010 (Ciba-Geigy) were irradiated under vacuum at room temperature w
ith different doses of gamma rays from a Co-60 source. Changes in stru
cture and the average molecular weight were followed by gel permeation
chromatography and low angle laser light scattering. The critical dos
es for gelation were determined as a function of the antioxidant conce
ntration. Theoretical calculations to predict the evolution of molecul
ar structure with extent of radiation were performed using a probabili
ty model. The agreement between the calculated and the measured molecu
lar weights is very good.