The mechanical properties of unfilled NR latex (NRL) and SSNRL films for both dispersion methods are presented in Table 4. The unfilled NR latex films showed higher tensile strength owing to the ability to strain induced crystallization behavior compared to filled NR latex films. For filled NR latex films, the ball milled SSNRL films showed slightly higher tensile strength compared to the ultrasonic SSNRL films due to the smaller size of starch particle in the former. For the tear strength, the addition of fillers normally improved the tear strength due to the existing of the fillers in the NR latex matrix able to deviate the crack propagation hence contribute to the high strength. The lower tear strength value of ball milled SSNRL films is mainly due to the reduction of particle size of the starch. Smaller starch particles size provides less potential to restrict the crack growth during deformation and deviated the cracks. In general, M100 and M300 of ball milled SSNRL film are higher because of the stiffening effect caused both interaction of the sago starch particles with the rubber matrix19. The smaller particle size of the sago starch promotes better interaction with the rubber matrix20. Thus, good filler-rubber interaction contributes to the formation of immobilized or partially immobilized polymer phase and then strengthens the film.