Bilayer biodegradable films based on pumpkin oil cake (PuOC) and zein, as
well as pouches made from these materials, were prepared, and the changes of
their mechanical, physicochemical and barrier properties were analyzed during
four weeks of storage. Heat seal quality of formed pouches and composition of
the gas atmosphere in the pouches were also monitored. The results showed
that the bilayer film had a thickness of 300 ? 10 (?m), and no its changes
were observed during the storage time. The tensile strength of the tested
film increased slightly in the third week, but the elongation at break showed
a decreasing trend during the whole storage period. The decreases in the
moisture content, total soluble matter and swelling of the obtained film,
were also observed. After one month of storage, the O2 transmission rate of
tested films, increased from 27 to 64 (ml/m2 24h 1 bar), and the CO2 gas
transmission rate from 147 to 188 (ml/m2 24h 1 bar). The heat seal strength
of the PuOC/Zein pouches decreased during the whole storage period. The
percentage of O2 in PuOC/Zein pouches increased up to 7 times during the
storage period; however, the percentage of CO2 decreased up to 18 times
already after one week, and then remained stable in the rest of the storage
period. These results are, to a smaller extent, due to the gas transmission
rate through the material, especially for CO2 , and to a greater extent, due
to the low heat seal strength, which decreased through the storage period,
and probably influenced the content of the gases in the pouches.
PENGARUH SUHU AKTIVASI TERHADAP SIFAT FISIS DAN ELEKTROKIMIA ELEKTRODA SUPERKAPASITOR DARI LIMBAH DAUN AKASIA (Acacia mangium Wild)