Doğal Kauçuk Esaslı Atık Lateks Eldiven ve Poli(Etilen-ko-Vinil Asetat) Kullanılarak Yeni Termoplastik Elastomer Kompozitlerin Hazırlanması ve Sönümleme Özelliklerinin İncelenmesi

Abstract

In recent years, thermoplastic elastomers (TPEs) have become technologically important as elastomeric rubber-plastic mixtures. The intensive use of rubber materials in our daily life and industrial areas is due to a significant combination of properties, low mass and ease of processing. The rapid development of the industry has led to an high increase in rubber use and production. Therefore, the increase in the production of rubber materials also caused a significant increase in the rate of waste rubber in the world. Considering these issues, recycling is one of the best options. Waste is generated during the extraction of raw materials, the processing of raw materials into intermediate and final products, the consumption of final products and other human activities. There are many studies aimed at disposing of these wastes and recycling them as useful products. Recycling of disposable glove wastes from natural rubbers is among these studies. In the aim of the thesis, it is ensured that latex glove wastes produced from natural rubber formed as a result of excess production or faulty production are recycled as useful product. Therefore, powdered latex gloves were decided to be mixed with ethylene vinyl acetate (EVA). First of all, 6 different mesh sizes of sieves ranging from 355μm to 1000μm were used in order to make size analysis of latex glove powders (LAT). As a result of the sieving process, 80% of the latex glove powder has a particle size range of 710-1000 μm and 20% has a particle size greater than 1000 μm. There are 3 different EVA-latex mixtures were prepared for investigate the effect of change in lateks powder particle size on mechanical properties. Then, tensile test was applied to these mixtures. According to the results, the system showing the highest tensile improvement is 60EVA40LAT mixture. It has been observed that % elongation value increased by 24.61%, tensile strength by 10.87%, elastic modulus value by 12.5%. As a result of tensile test, it was seen that elastic modulus, breaking strength and elongation at break values decreased with increasing latex ratio in the mixture. As a result of the tensile test, the mechanical properties of the mixtures having particle size range of 710-1000 μm were found to be higher. In order to investigate the effect of latex glove powder on mechanical properties with increasing ratio in the mixture, mixture of 100% EVA with no latex and 7 different EVA-Latex mixtures with a latex ratio of 20% to 95% was prepared. Tensile, compression and hardness tests were applied to analyze the mechanical properties of the mixtures. As a result of tensile test, 5EVA95LAT mixture has the lowest mechanical properties with 4.8 kPa elastic modulus, 0.86 MPa tensile strength and % elongation values at 201 MPa. The mixture with the highest tensile test values containing latex content is 80EVA20LAT mixture. The 80EVA20LAT mixture showed 232.5 kPa elastic modulus, 4.31 MPa tensile strength and % elongation at 220.3 MPa. To observe the compressive behavior of the mixtures, a 10-cycle compression test was applied under 10%, 20%, 30%, 40% and 50% compression ratio. Curves obtained from compression test, the absorbed energy values of the mixtures were calculated and the damping properties of the mixtures were determined. As a result, it was observed that the value of the absorbed energy and viscosity decreased and the elasticity increased with the increase of latex ratio in the mixture. According to the shore A and D-type hardness test, the hardness values decreased with the increase in the amount of latex in the mixture. The main purpose of the thesis is to ensure the recovery of latex glove powder by keeping it high in the mixture. The results obtained from EVALAT mixtures showed that the increase in the amount of latex in the structure caused a decrease in mechanical properties. In order to increase the compatibility between EVA and latex, it was decided to graft with maleic anhydride (MAH). For seeing the effect of grafting with MAH, grafted mixtures containing EVA and latex in the same proportions as EVALAT mixtures were prepared. After that, FTIR analysis of the grafted mixtures were performed. In the analysis, FTIR spectra of grafted and ungrafted mixtures with maleic anhydride having the same EVA-Latex ratio were compared and changes in wavelength of the grafted mixtures were determined and interpreted. Then, tensile, compression and hardness tests were applied to the same standards with ungrafted mixtures. As a result of tensile test, elastic modulus, tensile strength and elongation at break were increased with MAH grafted mixtures compared to ungrafted mixtures. When the tensile test results of the grafted and uninoculated mixtures were mixed, the 5EVA95LAT-g-MAH mixture showed the highest increase in elastic modulus values, 20EVA80LAT-g-MAH mixture showed the highest increase in tensile strenght and 80EVA20LAT-g-MAH mixture showed the highest increase in % elongation. According to the calculated absorbed energy values from compression tests, the most effective system was the 40EVA60LAT-g-MAH mixture. With respect to the hardness test results, the hardness values of the grafted mixtures with MAH increased compared to the ungrafted mixtures. To sum up, as a result of grafting with MAH, a significant increase in mechanical properties was observed compared to ungrafted mixtures. In consequence of the experimental studies, positive results were obtained as a result of the compatiblization process in EVALAT-g-MAH composite systems grafted with maleic anhydride and the recovery of waste latex gloves made of natural rubber as a useful product. In this way, waste rubber gloves, according to the results obtained from the mechanical tests can be used as a useful product in the appropriate application area has been made.