Hardness of the samples was measured with the help of Shore-Durometer as per ASTM D-2240. The instrument consists of a
calibrated spring to provide the intending force. The load imposedby the spring varies with the indentation. Reading was taken after10 s of the indentation when firm contact had been established with the specimen and the mean value of three measurements is reported. Minimum thickness of the specimen for the last test is 4 mm.