deflection temperature under load dtul was recorded using a dma q800 instrument ta instruments new castle del usa by measuring the temperature at which the deflection of the specimen thin film 15 mm long 13 mm wide and 0 5 mm thick corresponded to the strain 0 121 that would be induced with the astm load of 0 455 mpa the heating rate was 2 u00b0 c minute the storage modulus was measured using a dma q800 instrument ta instruments new castle del usa on a thin film sample using a heating rate of 2 u00b0 c minute and a frequency of 10 hz the tensile properties were measured according to astm d638 03 using a type i specimen the gardner impact was measure according to astm d5420 04 using ga geometry the oxygen flux of film samples at zero percent relative humidity at one atmosphere pressure and at 25 u00b0 c was measured with a mocon ox tran model 2 20 mocon minneapolis minn a mixture of 98 nitrogen with 2 hydrogen was used as the carrier gas and 100 oxygen was used as the test gas prior to testing specimens were conditioned in nitrogen inside the unit for a minimum of twenty four hours to remove traces of atmospheric oxygen the conditioning was continued until a steady base line was obtained where the oxygen flux changed by less than one percent for a thirty minute cycle subsequently oxygen was introduced to the test cell the test ended when the flux reached a steady state where the oxygen flux changed by less than.