Poli(Epiklorohidrin-Ko-(Etilen Oksit)-Ko-(Allil Glisidil Eter)) (GECO)’nun Yapısal Parametrelerinin Epiklorohidrin Temelli Elastomerlerin Mekanik ve Dinamik-Mekanik Özelliklerine Etkisi

Abstract

Elastomers containing epichlorohydrin (ECH) not only possess the dynamic properties of natural rubber but also exhibit superior resistance to fuel, oil, and chemicals. These elastomers have high heat resistance and low-temperature flexibility due to the chloromethyl groups attached to oxygen-containing saturated main chains. In the polymer industry, in addition to homopolymers of epichlorohydrin, co- and terpolymers formed with ethylene oxide (EO) and allyl glycidyl ether (AGE) monomers are industrially produced. Thanks to advancements in production methods, the industrial use of the ter- polymer poly(epichlorohydrin-co-ethylene oxide-co-allyl glycidyl ether), abbreviated as GECO, has been increasing. GECO elastomers can be prepared with different physical properties, such as vibration damping and mechanical strength, depending on the monomer ratios. In this thesis study, elastomer blends of GECO polymers with varying ECH, EO and AGE monomer ratios were prepared according to specific formulations, and the mechanical, thermo-mechanical, and damping properties of the obtained elastomers were examined. The aim of the study was to investigate the effects of GECO’s structural parameters on mechanical and thermo-mechanical properties. In the study, different types of GECO polymers, containing varying ECH, EO and AGE monomer ratios were used to prepare various elastomers with the curing agent 2,4,6-Trimer-capro-s-triazine (Trithiocyanuric acid) (TMT) and silica (Coupsil 6109) and phenolic resin as filler materials and other auxiliary chemicals. For this purpose commercially available GECO polymers with varying monomer ratios produced by the Zeon Company under the codes T3000LL, T3100, T3102, and T3108 were used. The curing properties of the prepared formulations were examined using a moving die rheometer (MDR) at temperatures of 170, 180, 190, and 200 °C. The MDR data obtained were used to determine the optimal curing conditions for GECO mixtures and to analyze curing kinetics. After determining the optimal curing conditions, the mechanical properties of the GECO mixtures were examined using a universal testing machine. The influence of the structural properties of GECO polymers on their mechanical properties was analyzed by evaluating stress-strain curves. To investigate the dynamic-mechanical properties of GECO elastomers, cyclic compression tests were performed on disk-shaped samples cured under optimal conditions and changes in the energy damping, stress relaxation, and permanent deformation characteristics were investigated. The temperature-scanning stress relaxation (TSSR) behavior of GECO elastomers was analyzed in the temperature range of 25-300 °C using a TSSR device. Through TSSR analyses, the effects of the structural parameters of GECO polymers on their long-term mechanical performance were determined. As a result of the evaluations, among the ECH, EO, and AGE monomers, the EO monomer was found to have the most significant impact on physical properties. The elastomer prepared with T3108, which had the highest EO content, exhibited the highest energy damping capacity, whereas the elastomer prepared with T3100, which had the lowest EO content, had the lowest energy damping capacity. Besides the EO content, it was determined that poly dispersity index and long chain branching were also important factors that influenced the mechanical properties of elastomers. The results of this study contribute to the literature on the preparation of GECO-based functional elastomers and on the determination of energy dissipation properties that have not been previously presented in this field.