ASTM D570 standard covers method of determination of swelling in water of jute composite8. This test was done to determine the hydrophilic nature of 3 cm x 2.7 cm x 0.4 cm jute-based natural rubber composite. The average of the three values
obtained for the change in thickness expressed as a percentage of the original aver­age thickness is reported as the swelling value.

Thickness of swelling in water was measured as per Eq. (5),

Swelling Thickness, T s= ——— xl00 (5)

Ti

where T1 is initial thickness and T2 is the final thickness after water absorption. Table 6.4 gives the percentage of thickness swelling of samples in water at 24 h. The saturation point occurs at 24 h and thickness swelling is approximately l00%.

6.5.1.1 BIODEGRADATION

This test was done to evaluate microbial biodegradation activities of jute composite by burying in soil9. Sample dimensions: 10 cm x 5 cm * 0.4 cm of the jute compos­ite was used for the test. Weight of l0 pieces of rectangular shaped samples were measured and buried in soil mixture containing garden soil, cow dung and sand (2:1:1, w/w). After 15 and 30 days the samples were removed, cleaned properly and finally kept in oven at 100°C till a constant weight was obtained. The weight loss of the samples after 15 days was 3.74% and 30 days was 6.28%.