Effect of Different Types of Filler and Filler Loadings on the Properties of Carboxylated Acrylonitrile-Butadiene Rubber Latex Films

The effects of different types of fillers and filler loadings on the properties of carboxylated nitrile rubber (XNBR) latex were identified. Silica, mica, carbon black (CB; N330), and calcium carbonate (CaCO3) were used as fillers with filler loadings of 10, 15, and 20 parts per hundred rubber. Furnace ashing and Fourier transform infrared analysis proved that interaction existed between the fillers and XNBR latex films. The morphology of the filled XNBR films was significantly different for different types of fillers. Mica and CaCO3 fillers showed uneven distribution within the XNBR film, whereas other fillers, such as silica and CB, showed homogeneous distribution within the films. In the observation, silica and mica fillers also illustrated some degree of agglomeration. The mechanical properties (e. g., tensile and tear strengths) showed different trends with different types of fillers used. For silica and mica fillers, the mechanical properties increased with filler loadings up to a certain loading, and decreased with higher filler loadings. For CB filler, the mechanical properties increased gradually with increasing filler loadings. CaCO3 fillers did not increase the mechanical properties. The crosslinking density of the XNBR films increased when they were incorporated with fillers because of the presence of elastomer-filler and filler-filler interactions. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 119: 2815-2823, 2011