Hakan Akat

Synthesis, Characterization and Thermal Degradation Kinetics of Poly(imino Isophthaloyl Imino (2,4,8,10-tetraoksoaspiro [5,5] Undekan-3,9-dipropylene))

A new polymer, poly(imino isophthaloyl imino (2,4,8,10-tetraoksoaspiro [5,5] undekan-3,9-dipropylene)) [poly(IPIT)] was synthesized by an interfacial polycondensation reaction. The characterization of poly(IPIT) was conducted by using FT-IR, 13C-NMR, TG and DTA techniques. The kinetics of the thermal degradation of poly(IPIT) was investigated by thermogravimetric analysis at different heating rates. TG curves showed that the thermal decomposition of poly(IPIT) occurred in three stages. The apparent activation energies of thermal decomposition for poly(IPIT), as determined by the Tang method (TM), the Flynn-Wall-Ozawa method (FWO) and the Kissinger-Akahira-Sunose method (KAS) are 58.09, 57.7 and 61.0 kJ/mol for the first stage decomposition, 106.1, 105.6 and 109.8 kJ/mol for the second stage decomposition, and 138.1, 137.5 and 141.4 kJ/mol for the third stage decomposition, respectively.

Synthesis, characterization, and thermal degradation kinetics of poly(styrene-co-N-maleimide isobutyl polyhedral oligosilsesquioxane)

This study demonstrated that poly(styrene-co-N-maleimide isobutyl polyhedral oligosilsesquioxane (POSS)) (P(S-co-NMIP)) was successfully prepared using free radical polymerization. For this purpose, firstly, N-maleimide isobutyl POSS (NMIP) was synthesized using aminopropyllsobutyl POSS (POSS-NH2) and maleic anhydride. Secondly, P(S-co-NMIP) was synthesized using styrene, NMIP, and 2,2-azobis(isobutyronitrile) as initiator in tetrahydrofuran for 24 h at 75°C to give copolymer. The synthesized polymer and compounds were characterized by proton nuclear magnetic resonance, gel permeation chromatography, and Fourier transform infrared spectroscopy. Thermal behaviors of P(S-co-NMIP) were analyzed using thermogravimetric and differential scanning calorimetric analyses. The apparent activation energies (Es) for thermal degradation of P(S-co-NMIP) were obtained by integral methods (Flynn–Wall–Ozawa (FWO) and Kissinger). P(S-co-NMIP) was heated thermogravimetrically under various heating rates such as 5, 10, 15, and 20°C min−1 at a temperature range of 30–1000°C to determine their thermal degradation mechanisms. The values of E for P(S-co-NMIP) were found to be 127.5 ± 2.3 and 134.4 ± 14.8 kJ mol−1 for FWO and Kissinger methods, respectively. Also, the values of E of synthesized copolymer (P(S-co-NMIP)) were compared with styrene-co-maleic anhydride copolymer in literature.

Synthesis, characterization and thermal degradation of cross-linked polystyrene using the alkyne-functionalized esters as a cross-linker agent by click chemistry method

In this study, it has been demonstrated that cross-linked polystyrene (CPS) was successfully prepared by using click chemistry. For this purpose, firstly, poly (styrene-co-4 chloromethylstyrene) with 4-chloromethylstyrene was synthesized. Secondly, alkyne-functionalized esters (dipropargyl adipate, dipropargyl succinate) were obtained using propargyl alcohol, adipoyl chloride and succinyl chloride. Azide-functionalized polystrene (PS-N3) and dipropargyl adipate (or dipropargyl succinate) were reacted in N,N-dimethylformamide for 24 h at room temperature to give CPS. The synthesized polymer and compounds were characterized by nuclear magnetic resonance (1H-NMR), gel permeation chromatography (GPC), fourier transform infrared spectroscopy (FT-IR) and thermogravimetric (TG/DTG) analysis.. The surface properties were investigated by Scanning Electron Micrography (SEM).

Synthesis and radical polymerizations of acrylamides having Gabapentin moieties

Abstract The synthesis and radical polymerizations of several acrylamides having Gabapentin(GBP) moieties were examined. The monomers were prepared by the reactions of 1-aminomethyl-1-cyclohexane acetic acid salts with acryloyl chloride in the presence of triethylamine in moderate yields. Radical polymerizations of the monomers were carried out in the presence of AIBN (3 mol%) in Dimethyl formamide (DMF) with moderate yield. The thermal behavior of the polymers was investigated by thermo gravimetric analysis (TGA) and differential scanning calorimeter (DSC) to determine the thermal degradation pattern and glass transition temperature (Tg). The resulting polymers showed a thermal stability up to 400 °C. The glass transition temperatures of the polymers were found not to depend on the substituents of the GBP moieties. Nearly the same TG’s were observed for polymers. We found the molecular weights of the polymers to be between 20700 and 2300 g/mol. We obtained poly(HFCHA) as a water-soluble polymer. Poly(MFCHA), poly(EFCHA) and poly(PFCHA) were soluble in common solvents.