Health & Environmental Research Online (HERO)


Print Feedback Export to File
4697860 
Journal Article 
ELECTRONIC SPIN RESONANCE STUDIES OF GAMMA-IRRADIATED PS/PP (80/20) BLENDS WITH 2.5WT% SBS, AFTER FIVE YEARS OF STORAGE IN AIR 
Davidson, E; Reyes, J; Moronta, D; Sciamanna, R 
2011 
Yes 
Interciencia
ISSN: 0378-1844 
36 
5 
365-369 
English 
WOS:000291234200007 
This study is a continuation of previous ones aimed at improving the stability of polystyrene/polypropylene (PS/PP 80/20) blends aged for 0, 4 and 5 years in non-controlled open air storage after gamma-irradiation with different amounts of compatibilizer (block styrene-butadiene-styrene (SBS), styrolux with 48wt% of styrene and stereon with 43wt% of styrene). gamma-irradiation from a (60)Co source at a dose rate of 4.8kCy.h(-1) and at integral doses of 10, 25 and 50kGy, in air at room temperature (similar to 298 degrees K) after 5 years-aging in non-controlled open air storage, to evaluate the oxidative degradation resistance of (PS/PP (0/20) blends, with and without compatibilizer SBS, styrolux and stereon at 2.5wt%. Electron spin resonance showed that peroxide radicals prevail as a consequence of gamma-irradiation and that there is an enhancement of exchange interactions and the presence of groups of free radicals. The blend with SBS, 2.5144% stereon has a higher concentration of free radicals than the blend with 2.5wt% styrolux. For both blends the dependence of free radical concentration, Ipp, and resonance line width, Hpp, on the gamma-irradiation dose are represented by first order kinetics (monomolecular process). In addition, a higher formation of free radicals is observed in comparison with non aged samples of PS/PP (80/20), 7.5wt% SBS, styrolux, gamma-irradiated previously analyzed. Color centers are not observed on the studied blends. 
Compatibilizer; Electronic Spin Resonance; Gamma Radiation; Polystyrene