Polytetrafluoroethylene (PTFE)/carbon black (CB) microporous membranes produced from PTFE/CB composite particles prepared by heterocoagulation process

Abstract

Polytetrafluoroethylene (PTFE)/carbon black (CB) microporous membranes with excellent properties were successfully prepared via heterocoagulation process and mechanical stretching method. Heterocoagulation was achieved using PTFE emulsion with 26% solid content, an intermediate product of the commercial PTFE dispersions with 60% solid content, and CB dispersions to prepare PTFE/CB composite particles by mechanical stirring, which is the unique content in this article. Furthermore, in order to obtain uniform distribution of CB particles within the membrane matrix as well as improve color uniformity and mechanical strength of the microporous membranes, CB was pretreated by a titanate coupling agent (NDZ-201). The PTFE/CB composite particles were then used to prepare the PTFE/CB microporous membranes via mechanical stretching operation. Several important properties of the prepared PTFE/CB microporous membranes, such as tensile strength, porosity, contact angles, morphology, and dynamic mechanical properties, were investigated. Results showed that the fabricated PTFE/CB microporous membranes possessed color uniformity, high tensile strength, and high hydrophobicity.