Tez özetleri Astronomi ve Uzay Bilimleri Anabilim Dalı

Clay Modification By Simultaneous Polymerization

In this study, a clay originated from Balikesir region and its organically ion exchanged form (org-clay) by octadecyl amine (ODA) was modified by in-situ polymerization of Acryamide/N,N-dimethyl aminoethyl methacrylate (AAm/DMAEM) and Acryamide/2-vinyl pyridine (AAm/2-VP) monomer pairs. Some structural and physical properties of the samples were investigated in detail.

Structural and physical properties of the samples were examined by Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD) and Thermogravimetric Analysis (TGA).

FTIR study showed that copolymer structures were formed into clay galleries. Yet the characteristic absorption peaks of octadecyl amine (ODA) and copolymers were not individually identified clearly due to their structural similarity, it could be assessed that organic groups (ODA) might be remained onto clay layers based on the FTIR characterization of the samples prepared with the org-clay.

It was obtained from the XRD analysis of the samples that low amount of clay loaded samples of AAm/DMAEM series copolymers having various clay amount showed mainly exfoliated structure. On the other hand, high clay loaded samples showed intercalated/exfoliated mixed structure in this series. It was found that intergallery spacings (d₀₀₁) of clay were lower for the AAm/2-VP samples than those of AAm/DMAEM counterparts. While the values of d₀₀₁ is about 1.2 nm for the natural clay, it is found to be between 1.25-2.20 nm for the intercalated samples.

TGA study indicated that the samples showed degradation with multiple steps. It was also found that the thermal stability of samples series prepared by using of AAM/2-VP was higher than those of AAm/DMAEM series. Moreover, thermal stability of the samples prepared with the natural clay was higher than those prepared with org-clay. This result could be attributed to low thermal stability of organic amine groups which might be remained into clay galleries. TGA results implied that thermal stability of the samples increased with the increasing of clay amount in the sample composition. This behavior is more pronounced in the samples prepared with natural clay.