The effect of polystyrene blocks content and of type of elastomer blocks on the properties of block copolymer/layered silicate nanocomposites

• Published in: Journal of alloys and compounds Vol. 616; pp. 569 - 576
• Main Authors: Vuluga, Zina, Panaitescu, Denis Mihaela, Sanporean, Catalina Gabriela, Radovici, Constantin, Gabor, Raluca, Nicolae, Cristian Andi, Corobea, Mihai Cosmin, Iorga, Michaela, Florea, Dorel
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 15.12.2014; Elsevier
• Subjects: AFM; Applied sciences; Composites; DMA properties; Elastomers; Exact sciences and technology; Forms of application and semi-finished materials; Inorganic materials; Nanostructured materials; Polymer industry, paints, wood; Technology of polymers; X-ray diffraction; X-ray diffraction; AFM; DMA properties; Nanostructured materials; Inorganic materials; Elastomers; Differential scanning calorimetry; Atomic force microscopy; Stacking sequence; Elastomer; Hardness; X ray diffraction; Dynamic mechanical analysis; Dynamic method; Fracture toughness; Nanocomposite; Stiffness; Block copolymer; Styrene copolymer
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2014.07.144

•TPE/nanosilicate interactions function of PS content and elastomer type were studied.•Maximum silicate concentration uniformly dispersed by melt intercalation was established.•Nanosilicate splits into stacks of 3–4 layers due to interaction with SBS, shown by XRD.•Increase of stiffness and maintaining of toughness observed up to 30wt.% nanosilicate. The aim of the present work was to understand the block copolymer/layered silicate interactions as function of polystyrene blocks content and of the type of elastomer blocks in the block copolymer. Using dynamical melt intercalation method, styrene triblock copolymer/Dellite 67G nanocomposites were obtained. The properties of nanocomposites were evaluated by morphological (XRD and AFM), thermal (DSC), mechanical and dynamic mechanical (DMA) analysis. The polystyrene chains of block copolymer preferentially intercalated into the galleries of Dellite 67G and probably interacted with the surface of the silicate increasing the uniform dispersion of the silicate in the polymer matrix. Homogenous nanocomposites having ordered lamellar structure were obtained. The silicate agglomerates were split into stacks of 3–4 layers which were evenly dispersed in the polymer matrix. The block copolymer/Dellite 67G interaction was reflected in the increasing of stiffness (modulus and hardness) with maintaining of toughness, up to 30wt.% Dellite 67G. Over 30wt.% silicate the mechanical properties decreased, probably as result of the agglomeration of silicate particles. AFM investigation brought complementary information to XRD patterns of the nanocomposites revealing a second type of intercalated structures with interlamellar distance higher with one order of magnitude.