SOYA YAĞI BAZLI POLİOL İLE KARBOKSİLLENMİŞ-POLİ(ETİLEN GLİKOL) POLİMERİNİN KONDENZASYON TEPKİMESİ İLE ÇAPRAZ BAĞLI POLİMERLERİN HAZIRLANMASI

Abstract

In this study, the synthesis of cross-linked PEGDASPOL polymers via condensation polymerization of soybean oil based polyol with end group carboxylated polyethylene glycol was investigated. PEGDASPOL synthesis was occured in 3 steps. At first, soybean oil was epoxidized through formic acid/hydrogen peroxide method and reaction yield was characterized by FT-IR, 1H-NMR, 13C-NMR and MALDI-TOF mass spectrometry techniques. In the FT-IR spectrum of epoxidized soybean oil (ESO), the vibration peak of epoxy group is observed at 828 cm-1, epoxy proton peaks at 3,0-3,2 ppm in 1H-NMR spectrum and epoxy carbon peaks between range of 50-60 ppm in the 13C-NMR spektrum. The molecular weight is determined as 985 g/mol by MALDI-TOF-MS mass spectrometer, and epoxy content is found to be 3,81 mmolepoxy/ gESO with Paquot method. In the second step, hydroxylated ESO was achived by ring opening reaction with water and perchloric acid. FT-IR, 1H-NMR, 13C-NMR and MALDI-TOF-MS mass spectrometry were used to characterization of SPOL throughout hydroxylation procedure. In the FT-IR spectrum of SPOL, the peak of epoxy group at 828 cm-1 was disappeared and hydroxy band was formed at 3400 cm-1. Protons of the epoxy (-CHOCH-) group with chemical shift of 3.0-3.2 ppm and the methylene group adjacent to the epoxy group with chemical shift of 2.8-3.0 ppm were disappeared in the 1H-NMR spectrum, At 3,3-4,1 ppm, proton peak of OH group was observed. In 13C-NMR spectrum peaks of the epoxy carbon atoms which observed at 50-60 ppm were disappeared. MALDI-TOF-MS mass spectrometry analysis of SPOL showed that two distinct molecular weight distributions consisting of 713,1057 based diglyceride and triglyceride molecules. The amount of hydroxyl was found to be 5.69 mmolOH/gpolyol. At the third stage, hydroxyl end groups of PEG polymers with molecular weight 600,1000,1500, g/mol were carboxylated through NaOCl oxidation in the presence of TEMPO (2,2,6,6-Tetramethylpiperidin-1-yl)oxyl) catalyst and PEGDA600, 1000, 1500 polymers were prepared. Spectroscopic properties were investigated by FT-IR, 1H-NMR, 13C-NMR and MALDI-TOF-MS spectroscopic techniques whereas thermal properties were characterized by TGA and DSC studies. In the FT-IR spectrum of PEGDA polymers, a broad band around 3500-2500 cm-1 due to carboxylic acid (-COOH) and a stretching band at 1745 cm-1 due to carboxylic acid carbonyl (C=O) were observed. In the 1H-NMR spectra of PEGDA 600, 1000 polymers carboxylic acid proton peaks appeared at 8,2 ppm, 7,1 ppm and 6,6 ppm, respectively, whereas in 13C-NMR spectra of those polymers carboxylic acid carbon peaks were observed between 170-172 ppm. The number average molecular weights (Mn) of PEGDA 600, 1000, 1500 polymers studied by MALDI-TOF, were determined as 710, 1030, 1600Da, respectively. PEGDA polymers were converted to acid chlorides using thionyl chloride (PEGDACl). Influence of the chloride attached to the FT-IR spectra of the PEGDACl600, PEGDACl1000 and PEGDACl1500 samples; The peak of the carboxylic acid carbonyl (C=O) stretching at 1745 cm-1 was disappear and characteristic peak formation of the acid halide carbonyl (R-CO-Cl) peak at 1800 cm-1 and C-Cl bending at 750 cm-1 was observed. At the final stage, PEGDACL and SPOL polymers were mixed at molar ratios of 1.32, 1.08, 0.91, 0.79 molPEGDA/molSPOL to synthesize cross-linked PEGDASPOL polymers. The synthesized products were characterized by FT-IR, TGA, DSC. FT-IR spectra of PEGDASPOL polymers is disappearance of the acyl halide (R-CO-Cl) peak observed at 1800 cm-1 in the spectrum of PEGDACl samples. In addition, the hydroxy band observed at 3400 cm-1 in the SPOL spectrum was observed to be decreased in the spectrum of PEGDASPOL polymers. These changes; The acyl chloride of PEGDACL is the source of the esterification reaction of the hydroxy group of SPOL. It has been determined that cross-linked PEGDASPOL polymers are insoluble in acetone, THF, and water, leaving over 90% by weight of insoluble cross-linked structure. The thermal stability of PEGDA600SPOL, PEGDA1000SPOL and PEGDA1500SPOL cross-linked polymers were measured at a heating rate of 10 ˚C / min and TGA thermograms were recorded at 25-700 ˚C in nitrogen vi atmosphere and samples were found to exhibit a one-step thermal decomposition behavior. The thermal transitions of the PEGDA600SPOL, PEGDA1000SPOL and PEGDA1500SPOL cross-linked polymers were determined by recording DSC thermograms at a temperature range of -80 to 160 ˚C in nitrogen atmosphere at heating rate of 20 ˚C / min. The common characteristic of all cross-linked PEGDASPOL polymers synthesized is that glass transition temperatures range from -30 to -54 ° C. It has been determined that PEGDA600SPOL and PEGDA1000SPOL polymers are mostly amorphous, PEGDA1500SPOL polymers are semi-crystalline.