Siloxane-imide block copolymer membranes with various siloxane contents were prepared and their dynamic viscoelasticity, sorption of carbon dioxide, and permeability of carbon dioxide, oxygen and nitrogen were studied. The siloxane-imide block copolymer consists of a microphase separated structure of imide-rich and siloxane phases, and the mechanical properties of the siloxane-imide block copolymer are well retained up to a siloxane content of about 20 wt%. The amount of carbon dioxide sorbed into the siloxane-imide block copolymer decreases with the introduction of siloxane, reflecting the less-sorptive capability of the siloxane group. The sorption behaviour of the block copolymers is interpreted in terms of a dual-mode sorption theory, which is applied to glassy imide-rich phases. On the other hand, the permeability coefficients of carbon dioxide, oxygen and nitrogen are remarkably increased with siloxane content when the latter is more than 10 wt%, and the permselectivity of oxygen to nitrogen is decreased with siloxane content. These behaviours are interpreted by considering the arrangement of the two phases in the membrane.
Посилання на статтю:
Structure and gas permeability of siloxane-imide block copolymer membranes: 1. Effect of siloxane content / Y. Tsujita*, K. Yoshimura, H. Yoshimizu, A. Takizawa and T. Kinoshita // Polymer. – 1993. – Vol 34. – P. 2597-2601.