The Effect of Acrylonitrile Concentration on Starch Grafted Acrylonitrile (ANS) Stability in Carboxylated Nitrile Butadiene Rubber (XNBR) Latex

Sago powder was grafted with acrylonitrile monomer in portion of 0.5, 1.5, 3.0, and 5.0 mol/AGU. The final amino-functional starch (ANS) was characterized by Fourier Transform Infrared (FTIR) analysis to observe the emerging of several significant peaks to verify the grafted cyano- (CN-) functional group. The degree of substitution (DS) and particle's stability of the ANS was determined by elemental and zeta potential analysis respectively. The relative DS of the acrylonitrile grafted onto starch with respect to the particle surface area indicated that, as the concentration of acrylonitrile increased, the degree of substitution / surface area (DS/SA) also increased. The process also reduced the particle size as the concentration of acrylonitrile increased. The optimum concentration obtained was 3.0 mol/AGU which shows strong band at wavenumber 2422 cm -1 representing the presence of high cyano (CN-) functional group in ANS as compared with other types of ANS.