2.4. Films mechanical properties
Mechanical behavior of TPS films was carried out using two
different devices. Tensile tests were performed in an Instron 3369
universal mechanical testing system (Instron, USA) using a crosshead speed of 2mm/min and a load cell of 50 N. Ten test specimens
(13 100 mm) were assayed for each film formulation and stressstrain curveswere calculated fromload-displacement data. Young’s
modulus (E), maximum tensile strength (sm) and elongation at
break (εb) were calculated according to ASTM D882-00 standard
method. Besides, resilience modulus (Ur) and yield strain (εy), as
well as toughness, were also obtained.
On the other hand, quasi-static assays in uniaxial conditionwere
performed in a dynamic-mechanical analyzer Q800 (TA Instruments, NewCastle, USA)with liquid nitrogen as cooling system,
using a clamp tension. At least ten specimens (60 30 mm) were
tested for each film formulation at isothermal conditions. Assays
were performed at 25 C from0.1 N up to specimen breakage using
a constant displacement velocity of 0.3 N/min and a preload force
ranged from 0.1 to 0.5 N. Stress-strain curves were recorded and
analyzed using the software Universal Analysis 2000. Same mechanical properties determined by tensile tests performed in the
Instron machine were also calculated from quasi-static assays. Reported results correspond to the mean value of each mechanical
property.