2.3. Flexural testing

A three point bending test setup was used to assess the flexural properties of the composites after conditioning in the various mediums. Specimens were rinsed, blotted dry and measured prior to testing. Measurements were taken at two places for length, width and height, and the average of both values was taken to calculate the flexural strength and flexural modulus. The composite specimens were loaded in a universal testing machine (UTM) (Shimadzu Corporation, Kyoto, Japan) with a load cell of 5 KN and crosshead speed of 0.5 mm/min until fracture occurred. Flexural strength, σ, in Megapascals (MPa) was calculated using the following equation:

where

P is the maximum load, in newtons, exerted on the specimens;

L is the distance, in millimeters, between the supports (10 mm);

B is the width, in millimeters, of the specimens measured prior to testing;

H is the height, in millimeters, of the specimens measured prior to testing.

Flexural modulus, E′, in Megapascals (MPa) was calculated using the following equation:

where F/D is the slope, in newtons per millimeter, measured in the straight-line portion of the load-deflection graph. L, B and H had been defined in the flexural strength equation. Flexural modulus was computed and subsequently converted to Gigapascal (GPa).