سنتز و بررسي اثر مشتق هاي دي فنيل كربنات بر روي تخريب نوري فيلم پلي اتيلن سبك

چكيده انگليسي :

Synthesis and Evaluation of Diphenyl Carbonate and its Derivatives on Photo Degradation of Low Density Polyethylene Siamak Bahrami ss bahrami@ce iut ac ir Date of Submission 2012 03 11 Department of Chemical Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiSupervisor S Nouri Khorasani saied@cc iut ac irAbstractNow a day there is an increasing demand for plastics in packaging It is necessary to use plastics that degrade Inthis research photo degradation of low density polyethylene films by means of non metallic pro oxidants such asdiphenyl carbonate and its derivatives as well as cobalt stearate was investigated Diphenyl carbonate s derivativeswhich were used in this study are 4 4 dichloro diphenyl carbonate 4 4 dinitro diphenyl carbonate 4 4 dihydroxydiphenyl carbonate and 4 4 dimethoxy diphenyl carbonate The derivatives of diphenyl carbonate were synthesizedby substitutive reaction of phenol and diphenyl carbonate in aqueous phase For each derivative of diphenylcarbonate 4 chlorophenol 4 nitrophenol hydroquinone and 4 methoxyphenol respectively are used Diphenylcarbonate and its derivatives were added to low density polyethylene in amount of 0 1 0 3 and 0 5 wt and thenpolyethylene films with an average thickness of 70 7 micrometer were manufactured using film blowing machine Polyethylene films with without pro oxidant were exposed to the ultraviolet radiation by two UV A lamps Characterization tests consists of FTIR gravimetric analysis viscometry and tensile were done on all samples beforeradiation as well as after spending 50 100 150 and 200 hours under radiation The results show that all samples withpro oxidants have a higher degradation rate than samples free of pro oxidant but their effects on the degradationrate are not the same It was also seen that a higher pro oxidant content in the film will lead to a higher degradationrate For the samples containing 0 5 wt of 4 4 dinitro diphenyl carbonate after 200 hours of exposing to UV carbonyl index and number of chain scission were 21 24 and 2 55 respectively while these factors for the sampleswithout pro oxidant were 2 83 and 0 092 Therefore it was concluded that among all non metallic pro oxidants 4 4 dinitro diphenyl carbonate had the most considerable effect on degradation rate of polyethylene films Afterchoosing 4 4 dinitro diphenyl carbonate as the most effective pro oxidant further experiments were done in orderto specify the effect of mixing it with cobalt stearate on the photo degradation of low density polyethylene films Three different samples were synthesized containing various amounts of 4 4 dinitro diphenyl carbonate 0 0 1 and0 5 wt and 0 1 wt of cobalt stearate in each one These samples were gone under same characterization tests asdone for the samples containing non metallic pro oxidants Carbonyl index after 200 hour of exposure to the UV forthe samples comprising 0 1 wt of cobalt stearate along with 0 0 1 and 0 5 wt of 4 4 dinitro diphenyl carbonatewere 15 07 18 47 and 27 17 respectively Furthermore the number of chain scission for these samples were 1 73 1 96 and 2 96 The results showed that cobalt stearate is more effective than 4 4 dinitro diphenyl carbonate fordegradation of low density polyethylene films It was also concluded that using both 4 4 dinitro diphenyl carbonateand cobalt stearate as pro oxidants together has a better effect on increasing the degradation rate in comparison withthe case in which one of the pro oxidants was used solely Keywords LDPE photo degradation ultraviolet radiation diphenyl carbonate s derivatives cobalt stearate

بهرامي، سيامك

سنتز و بررسي اثر مشتق هاي دي فنيل كربنات بر روي تخريب نوري فيلم پلي اتيلن سبك

پرتو ماوراء بنفش , كبالت استئارات