2.6. Tensile properties
Tensile strength (TS) and elongation at break (%E) in the machine
direction of the papers were evaluated using a material testing
machine (Lloyd LRX, Lloyd Instruments Ltd., Royston, UK), according
to a standard method of ISO 1924-2-1994. The experiments
were performed under controlled conditions, at 23 ◦C and 50% RH.
Ten rectangular paper samples (15 mm wide
×
100 mm long) were
cut from each type of paper and were tested using a double clamp
with a separation of 30 mm at a test speed of 20 mm/min. The clamp
separation was 100 mm and the strain rate was 20 mm/min. The
curve load vs. extension was recorded until the elongation at break
was reached. The TS was expressed in MPa and was calculated by
dividing the maximum load (N) by the cross-sectional area (m2).
Maximum elongation at break or percent elongation at break (%E)
was determined by dividing the extension at the moment of breakage
by the initial gauge length of the samples and multiplying by