Measuring Film Thickness and Mechanical Properties

The film’s thickness was measured using a hand-held digital micrometer (Digimatic Micrometer, QuantuMike IP 65, Mitutoyo, Japan) with an accuracy of 1 μm. The film thickness was measured at five random locations of each film, and their average value was reported. Each film’s mechanical properties were determined according to the standard method of ASTM D 882-88 using an Instron Universal Testing Machine (Model 5565, Instron Engineering Corporation, Canton, MA, USA). For the measurement, the film sample was cut with (2.54 × 15 cm) dimension using a precision double blade cutter (model LB.02/A, Metrotec, S.A., San Sebastian, Spain) [31 (link)]. The machine was operated in the tensile mode with an initial grip separation and crosshead speed set at 50 mm and 50 mm/min, respectively.