الفهرس 
AcknowledgmentOnly 14 pages are availabe for public view
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Abstract
The thesis deals with synthesis of a wide range of polyamide compositions, which is very important class of materials due to their potential applications in many fields. These fields of application include high modulus fibres, engineering plastics, adhesives and membranes. The most important field of application is separation membranes especially reverse osmosis ones. In particular, the properties of a membrane and its performance can be significantly improved upon hybridizing the material of the membrane (polyamide) with an inorganic nanoelement (e.g. montmorillonite). Thus, it was very important to study the impact of this insertion on a wide range of polyamide compositions with respect to the state of dispersion in the polymer matrix and the consequences on the glass transition and thermal stability which are functions of the surface treatment of the montmorillonite. This gives a profound understanding of the possibility of using some of these compositions for formulating membranes. The prepared compositions in this thesis can be briefly divided into three groups. As well known, polyamide can be prepared via interfacial polycondensation which depends on reaction of the monomers (diamine+diacid chloride) while dissolved in two immiscible phases (e.g. water and cyclohexane-chloroform (4:1) mixture. The reaction goes thus ahead at the interface between the liquids to the extent that the polymer product is no longer soluble in any of the phases then precipitates out of the medium while the reaction by-product, which is amine hydrochloride salt, goes preferentially to the aqueous phase which enables the reaction to step in the forward direction and leads to a high molecular weight polymer without reversibility of the reaction to the backward direction. Additionally, this can be performed within few seconds because the employement of the diacid in its activated form (diacid chloride) drives the reaction to proceed spontaneously without any complications. Accordingly, the prepared compositions in this thesis are divided into three groups. Group 1 was formulated solely from organic components without any addition of an inorganic element. The variables for this series were the type of amine whether linear diamine or triamine (which can act as a crosslinking agent) or mixtures of both. This can make the resulting compositions more robust and intact as revealed by SEM images. Also, employing a phase transfer agent is expected to push the reaction by decreasing the interfacial tension at the interface thus CTAB or PVA were individual parts of the formulations of group 1 dissolved in the aqueous phase. The formulations of group 2 are the same as group 1 while additional component, which is the untreated clay mineral (montmorillonite), was a part of the formulations at different feed ratios. Group 3 differs from group 2 in that the clay was treated in prior with CTAB as a phase transfer agent, fixed through electrostatic attraction at the surface of the clay platelets on the expense of the Na+, thus it exists in an immobilized form (not free as in the case of group 1).
Some of the synthesized samples were chosen out of the total listed samples to carry out complete characterization using different techniques such as fourier–transform infrared (FT-IR), thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM).
It can be concluded from the results that:
1-Samples prepared in absence of any clay:
-The presence of the triamine (DETA) as crosslinker as a part of the formulation can help to stabilize the structure of the resulting polyamide and improves its mechanical properties.