Poly(dimethylsiloxane) networks modified with poly(phenylsilsesquioxane)s: Synthesis, structural characterisation and evaluation of the thermal stability and gas permeability

• Published in: European polymer journal Vol. 44; no. 10; pp. 3080 - 3086
• Main Authors: Prado, L.A.S.A., Sforça, Maurício L., de Oliveira, Adriana G., Yoshida, Inez V.P.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-10-2008; Elsevier
• Subjects: Applied sciences; Exact sciences and technology; Exchange resins and membranes; Forms of application and semi-finished materials; Membranes; Polymer industry, paints, wood; Polymeric networks; Polysiloxanes; Sol–gel process; Technology of polymers; Polysiloxanes; Polymeric networks; Membranes; Sol–gel process; Transport properties; Silsesquioxane copolymer; Experimental study; Thermal stability; Crosslinked copolymer; Gas permeability; Sol gel process; Preparation; Supramolecular structure; Selective permeability; Membrane; Dimethylsiloxane copolymer; Siloxane copolymer; Sol-gel process
• ISSN: 0014-3057; 1873-1945
• DOI: 10.1016/j.eurpolymj.2008.07.002

Self-supported translucent films constituted of semi-inorganic polymeric materials were prepared by sol–gel process from poly(phenylsilsesquioxane) (PPSQ) and poly(dimethylsiloxane) (PDMS), modified by diphenylsilanediol (DPS), phenyltriethoxysilane (PTES) and/or tetraethoxysilane (TEOS). These materials were characterized by infrared spectroscopy (FTIR), X-ray diffraction (XRD) and thermo-gravimetric analysis (TGA). Permeability to N
2, O
2, CH
4 and CO
2 and selectivity for a specific gas pair were investigated using the time-lag method. In the gas separation process high permeability and selectivity coefficients were observed, particularly for the membrane containing DPS and PTES as additives, which presented potential applications in the separation of CO
2/CH
4 and CO
2/N
2. The materials also showed good thermal stability, which could be correlated to the relative amounts between di-functional (D), tri-functional (T) and tetra-functional (Q) silicon units.