Hessian cloth (commercial grade, bleached jute) was collected from Bangladesh Jute Research Institute (BJRI), Dhaka, Bangladesh and nonvulcanized NR was collected from Malaysian Rubber Board.
Composite Fabrication NR sheets were prepared by compression molding 1000C and 5 ton using heat press (CRAVER, USA, Model 3856). Two layers of hessian cloth and one layer of the prepared sheet were used to make composite. The NR sheet was Composite Fabrication NR sheets were prepared by compression molding 1000C and 5 ton using heat press (CRAVER, USA, Model 3856). Two layers of hessian cloth and one layer of prepared sheet were used to make composite. The NR sheet was placed between two layers of hessian cloth and the sandwich was placed in between two steel plates and heat pressed. The mold was cooled in another press. The temperature was maintained at about 1008C and pressure at 10 ton for 5 min and the cooling time was 5 min as well. Jute content was maintained at 40 wt%.
Irradiation Composites were irradiated using a Co-60 gamma source. In gamma radiation, a Co-60 source (25 kCi) model gamma beam 650 is loaded with source GBS-98 that comprises 36 double encapsulated capsules. Type C-252 loaded with Co-60 pellets was used. Composites were treated with gamma radiation with different doses (50–1000 krad).
Mechanical Tests The bending and tensile properties of the composites were evaluated via three-point bending test on a Hounsfield series S testing machine (UK) with a cross-head speed of 1 mm s1 at span distances of 20 and 46 mm, respectively. The dimensions of the test specimen were (ISO 14125): 60 15 2 mm3. Composite samples were cut to required dimensions using a band saw. Hardness of the composite was determined by HPE Shore – A Hardness Tester (model 60578, Germany).
WATER UPTAKE TEST OF THE COMPOSITE Water uptake tests of the composite, NR sheet, and jute fiber were performed in deionized water (about 500 mg) at room temperature (250C). The dimensions of the test specimen were 15 5 2 mm3 and placed into static glass beakers. The water uptakes of the samples were carried out upto 6 h. At set time points, samples were taken out and reweighed.
SOIL BURIAL TEST OF THE COMPOSITE The composites were cut into 60 30 2 mm3 size, weighed, and buried in soil containing 25% moisture at 6 in. depth. The specimens were taken out from the soil, washed with tap water to remove the soil particles from the surface of the specimens, and dried in oven at 500C for 24 h. Then, the loss of weight and mechanical properties of the composites was studied.
DEGRADATION TEST IN AQUEOUS MEDIUM The composites were cut into 60 30 2 mm3 size, weighed, and soaked in deionized water (about 500 mg) at room temperature (250C). The specimens were taken out after a desired time and dried in oven at 500C for 24 h. Then, the loss of weight and mechanical properties of the composites were studied.