Ordering Behavior of Layered Silicate Nanocomposites with a Cylindrical Triblock Copolymer

Abstract

Summary: 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.magnified imageThe 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.

Block copolymer–nanoparticle composites: Structure, functional properties, and processing

“…Nanoparticle concentration: A certain concentration of NPs should be incorporated into the polymeric matrices in order to achieve an optimum reinforcement [129,195]. Molecular dynamics simulations suggested that, at a given strain, the stress of polymer nanocomposites and the Young's modulus increased gradually with increasing NP amount [215], in close agreement with experimental results [216].…”

“…Favorable enthalpic interactions between NP and polymer can also lead to OOT and/or disorderto-order phase transition [129]. For example, hydrogen bonding of mercaptoacetic acid-coated CdSe NPs with P4VP made the polymer more stretched at the interfacial regions.…”

Rheological properties of asphalt/SBS/clay blends

“…It is important to note that, with styrenic block copolymers, the clay prevalently interacts with the styrenic component [26,27]. Lee et al showed that an organically modified montmorillonite leads to a change in the microphase separation behaviour of styrene-(ethylene-co-butylene)-styrene triblock copolymers (SEBS), thus also influencing the order-disorder transitions [28]. Analogously, the influence of the addition of small quantities of anisotropic layered silicates on the ordering of block copolymers was studied by Krishnamoorti et al [29] and Silva et al [30][31][32].…”

Preparation of a long-alkyl-chain silane grafted organic montmorillonite and its nanocomposite with SEBS

“…With the ability to control nano-ordered structures, block copolymer can be promising template matrices for selective dispersion of nanoparticles with competitive properties [4,5]. Many publications were related to block copolymer-based nanocomposites with tailored dispersion of nanofillers [6][7][8][9]. Montmorillonite (MMT), known as clay, is toxicologically safe nanofiller with layered silicates structure [10], while can bring a remarkable improvement in physical, mechanical [11] and barrier properties [12][13][14] of most polymers, even at very low concentration.…”