Modification of Egyptian Clay by Different Organic Cations

Elnady, Marwa; Saad, Gamal; Eid, Alaa; Aboelkhair, Malak

doi:10.21608/ejchem.2019.10855.1697

Modification of Egyptian Clay by Different Organic Cations

Document Type : Original Article

Authors

¹ Composite Lab., Advanced Material Division, Central Metallurgical Research and Development Institute.

² Chemistry department-Faculty of science -Cairo university

³ Central Metallurgical and Development Institute.

10.21608/ejchem.2019.10855.1697

Abstract

Nowadays, clay minerals are used extensively in a wide range of applications as nano additives for polymeric materials. Nevertheless hydrophilic characteristics of the nano additives reduce their degree of compatibility with polymeric chains. To overcome this problem it is necessary to modify the clay in order to render its surface more organophilic prior to the intercalation of the polymeric chains between its layers. In this work the Egyptian natural clay mineral montmorillonite (MMT) was modified with two cationic organic modifiers, namely hexadecyltrimethylammonium (HDTMA) and tributyl hexadecyl phosphonium using two different procedures. The first, using the magnetic stirrer while the second using a high speed mixer at different mixing times from 0.5 up to 2.5 hr. The samples with and without organic modifiers were characterized by X-ray diffraction (XRD), infrared spectroscopy (IR), thermogravimetric analysis (TGA), scanning electron microscope (SEM) and transmission electron microscope (TEM). XRD results revealed that the basal spacing of the organo-montmorillonite (OMMT) prepared using high speed mixer was larger than that using magenetic stirrer. The best result was obtained after 1.5 hr stirring in the high speed mixer. The modification of MMT was confirmed by FTIR as determined from –CH2 stretching vibration of the organic modifiers. The TGA analysis revealed that the MMT modified with tributyl hexadecyl phosphonium cation had high thermal stability than that modified with hexadecyl trimethyl ammonium cation. The amount of surfactants within organoclays were found to be found to be about 19 and 24%, respectively, for hexadecyl trimethyl ammonium bromide and tributyl hexadecyl phosphonium bromide. SEM demonstrated that the modified MMT exhibited a massive thin layered structure with some large flacks and some interlayer spaces. TEM images of the prepared organoclays showed exfoliated structure. This work proved to enhance the economical value of the Egyptian natural resources.

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