Effect of micro‐/nano‐scale aramid fibrillated fibers on the tensile properties of styrene‐butadiene latex

Micro−/nanofibers attract extensive attention of being used as reinforcing agents in polymer composites. Fibrillated fibers have a hierarchical network structure, and a larger specific surface area. Thus, they provide additional anchorage sites in the composite, enhancing the bonding strength between different constituents. In this work, aramid fibrillated micro−/nanofibers (AFMNs) were prepared by a refining process. Styrene‐butadiene latex (SBL) was used as the matrix, and it was mixed with AFMNs, formed AFMN/SBL composites. The mass fractions of AFMNs in the matrix are adjusted to 2%, 4%, 6%, and 8%. The microstructure of AFMNs and the fracture surfaces of AFMN/SBL composites were investigated by microscopical techniques. The results showed that the elastic modulus and tensile strength of AFMN/SBL composites are higher than that of the pure styrene‐butadiene latex film, except tensile strain. With the increase of fiber content, the elastic modulus and tensile strength of AFMN/SBL composites increased from 5.15 MPa to 19.66 MPa and 2.35 MPa to 4.23 MPa, respectively. However, the tensile strain decreased from 101% to 35%. The calculated elastic modulus of Halpin‐Tsai equation is close to the experimental values when the mass fractions of AFMNs is less than 6%.