Hydrophobicity and polymer compatibility of POSS-modified Wyoming Na-montmorillonite for developing polymer-clay nanocomposites

Rustam Hojiyev; Yusuf Ulcay; Mirabbos Hojamberdiev; Mehmet S Çelik; William M Carty

doi:10.1016/j.jcis.2017.03.034

Hydrophobicity and polymer compatibility of POSS-modified Wyoming Na-montmorillonite for developing polymer-clay nanocomposites

J Colloid Interface Sci. 2017 Jul 1:497:393-401. doi: 10.1016/j.jcis.2017.03.034. Epub 2017 Mar 7.

Authors

Rustam Hojiyev¹, Yusuf Ulcay², Mirabbos Hojamberdiev³, Mehmet S Çelik⁴, William M Carty⁵

Affiliations

¹ Department of Textile Engineering, Faculty of Engineering, Uludağ University, Görükle, Bursa 16059, Turkey; Department of Textile Engineering, Faculty of Engineering, International Turkmen-Turkish University, Koshi, Ashgabat 744000, Turkmenistan. Electronic address: rustamhodjiyev@gmail.com.
² Department of Textile Engineering, Faculty of Engineering, Uludağ University, Görükle, Bursa 16059, Turkey.
³ Department of Natural and Mathematic Sciences, Turin Polytechnic University in Tashkent, Kichik Halqa Yo'li 17, Tashkent 100095, Uzbekistan.
⁴ Department of Mineral Processing Engineering, Mining Faculty, Istanbul Technical University, Ayazaga, Istanbul 34469, Turkey.
⁵ Department of Ceramic Engineering, Kazuo Inamori School of Engineering, Alfred University, Alfred, NY 14802, USA.

PMID: 28314144
DOI: 10.1016/j.jcis.2017.03.034

Abstract

The aim of the present work was to investigate the hydrophobicity and polymer compatibility of aminopropylisooctyl polyhedral oligomeric silsequioxane (POSS) - modified Na-montmorillonite (Na-MMT) towards developing polymer-clay nanocomposites. The effect of different concentrations of POSS on properties of Na-MMT was studied. The intercalation ability of the POSS molecules into the Na-MMT interlayer was analyzed by X-ray diffraction. It was found that the d₀₀₁ value was increased with increasing the POSS concentration, indicating the successful intercalation of the POSS molecules into the Na-MMT interlayer. The d₀₀₁ value was 4.12nm at 0.4 cation exchange capacity (CEC) loading of POSS, increased at a slight rate upon further increase of CEC loading, and finally reached 4.25nm at 1.0 CEC loading of POSS. The results of the thermogravimetric (TGA) analysis confirmed the high thermal stability of the POSS-MMT. The thermal stability was defined as a 5% mass loss (T₅) at 0.2 CEC loading of POSS was observed at 352°C and slightly decreased with further increase in the POSS concentration. The porous properties, such as specific surface area (SSA), pore volume, and pore size were estimated by the adsorption of N₂ molecules on the Na-MMT surface. The SSA and pore volume were reduced with increasing the concentration of the POSS molecules due to the adsorption of the POSS molecules on the Na-MMT, while the pore size was increased upon the formation of macroporous structure. The interfacial interaction energy between water and POSS-MMT (ΔG_{Clay/Water/Clay}^IF) was used to evaluate the surface hydrophobicity, and a similar approach was also applied to assess the polymer compatibility of the developed composite. The obtained results confirm that the polymer compatibility of POSS-MMT prepared in this study is better than that of commonly used HDTMA-MMT.

Keywords: Compatibility; Contact angle; Hydrophobicity; Na-montmorillonite; Nanoclay; Nanocomposite; POSS; Porosity; Surface free energy; Thermal stability.

Publication types

Research Support, Non-U.S. Gov't