The RH inside the cell was always lower than the outside, and water vapor transport was determined from the weight gain of

the permeation cell. After steady state conditions were reached (about 2 h), ten weight measurements were made over 48 h. WVP was calculated according Equation (1): equation(1) WVP=(w/θ)×[(24×t)/(A×Δp)]WVP=(w/θ)×[(24×t)/(A×Δp)] wherein: WVP is the water vapor permeability [g mm m−2 d−1 kPa−1]; NLG919 w is the weight gain (from the straight line) [g]; θ is the time during which w occurred [h]; t is the average film thickness [mm]; A is the test area (cell top area) [m2] and Δp is the vapor pressure difference [kPa]. All specimens were evaluated in triplicate. Oxygen transmission rate (OTR) [cm3 m−2 d−1] of the films was measured at 23 °C and 75% RH on a 50 cm2 circular films using an oxygen permeation system (OXTRAN 2/21, MOCON, USA), in accordance

with ASTM F1927-07 (2007). A starch based film was sealed between two chambers (each one with two channels), the lower one supplied with O2 at a controlled flow rate (20 mL min−1) to keep the pressure constant in that compartment, and the other one was purged by a stream of nitrogen carrier gas (0.98 part of nitrogen and 0.02 part of hydrogen), at controlled flow rate (10 mL min−1). A colorimetric sensor determined the amount of oxygen transmitted through the film into the carrier gas. The oxygen find more Methane monooxygenase transmission rate was determined for all specimens in duplicate. The permeance (PO2) of the films was calculated according to Equation (2): equation(2) PO2=OTR/pPO2=OTR/pwherein: PO2 is the permeance of the films [cm3 m−2 d−1 Pa−1];

OTR is the oxygen transmission rate [cm3 m−2 d−1]; and p is the partial pressure of oxygen, which is the mol fraction of oxygen multiplied by the total pressure (nominally, one atmosphere), in the test gas side of the diffusion cell. The partial pressure of O2 on the carrier gas side is considered zero. The oxygen permeability coefficient (P′O2) was calculated as follows: equation(3) P′O2=PO2×tP′O2=PO2×twherein: P′O2 is the oxygen permeability coefficient [cm3 m−1 d−1 Pa−1]; and t is the average thickness of the specimen [mm]. Glass transition temperature (Tg) of BF was determined by differential scanning calorimetry, using a DSC TA 2010 controlled by a TA 4000 module (TA Instruments, New Castle, USA), with a quench cooling accessory, operated with nitrogen at 150 mL min−1. Temperature and melting enthalpy calibrations were performed with indium and bidistilled water and Milli-Q. Samples of about (2–5) mg were weighed in a precision balance (Scientech, SA210, USA), conditioned in hermetic aluminum pans (20 μL), and submitted to a temperature program, under inert atmosphere (100 mL min−1 of N2). In the first scan, after cooling the sample at −10 °C min−1 up to −60 °C, it was submitted to heating at 10 °C min−1 until 100 °C.