Ordering Behavior of Layered Silicate Nanocomposites with a Cylindrical Triblock Copolymer

• Published in: Macromolecular chemistry and physics 2006-02, Vol.207 (4), p.444-455
• Main Authors: Lee, Chung Ho, Kim, Hee Bong, Lim, Sung Taek, Kim, Hyun Seok, Kwon, Yong Ku, Choi, Hyoung Jin
• Format: Article
• Language: English
• Subjects: Applied sciences; block copolymers; Composites; Exact sciences and technology; Forms of application and semi-finished materials; nanocomposites; order-order transition; Polymer industry, paints, wood; rheological properties; Technology of polymers
• ISSN: 1022-1352; 1521-3935
• DOI: 10.1002/macp.200500445

The ordering behavior of the nanocomposites of organically modified montmorillonite (OMMT) with a cylindrical triblock copolymer of polystyrene‐block‐poly(ethylene‐co‐butylene)‐block‐polystyrene (SEBS) has been investigated by temperature‐resolved small‐angle X‐ray scattering (SAXS) and rheometry. X‐Ray diffraction (XRD) confirms that the polymer chains are successfully intercalated with the interlayer gallery of the silicates. The data obtained from the SAXS and rheological measurements show that the addition of OMMT leads to a change in the microphase separation behavior of SEBS in the nanocomposites. The molecular interaction between OMMT and the polystyrene (PS) chains of SEBS decreases the structural perfection of the self‐assembling, phase‐separated domain structure of the nanocomposites. Rheological data exhibit that the order‐order (TOOT) and order‐disorder transitions (TODT) of the SEBS/OMMT nanocomposites decrease with the addition of OMMT. The highest elongation at break is obtained at approximately 2% OMMT and its further addition to the mixture leads to decreases in tensile strength and elongation. The change in the storage modulus (G′) of a) SEBS, b) S98M2, c) S95M5, and d) S90M10, as a function of temperature in the range of 150 ≤ T (°C) ≤ 260.