Elastomerlerin metal yüzeylere kimyasal yapışması için karışım geliştirilmesi = Development of compositions for the chemical adhesion of elastomers to metal surfaces

Abstract

İlgili çalışmada, lastikli metal parçaların üretiminde kullanılan ve metalin yüzeyine uygulanarak lastiğin bu yüzeye vulkanizasyon aşamasında yapışmasını sağlayan kimyasal karışımların reçetelerinin hazırlanması hedeflenmiştir. Elastomer hamuru kullanılarak vulkanizasyon yöntemi ile üretilen lastik kaplamalı metal parçalar özellikle otomotiv, savunma, havacılık, denizcilik gibi sektörlerde kullanılmaktadır. Ülkemizde yüksek miktarlarda kullanılan ilgili lastik-metal yapıştırma kimyasallarının üretimini gerçekleştirebilmek ve ekonomimize katkı sağlamak amacı ile sunulan bu çalışma planlanmıştır. Sunulan çalışmada, ürünün yüksek miktarlarda kullanıldığı fabrika üretim proseslerinden saha çalışmalarına kadar ulaşan bir çalışma perspektifi oluşturulmuştur. Çalışmanın aşamalarıda metal kısımlara yapılan hazırlık aşamaları, yapıştırma uygulamaları, elastomer ile hamur karışımına girecek olan kimyasallar belirlenmiş, örnek karışımlar hazırlanmış, hazırlanan metal ve hamurun vulkanizasyon işlemi ile belli şartlar altında pişirilerek vulkanisayon ile metal-lastik fiksasyonu gerçekleştirilmiştir. Tüm bu ara proseslerin içinde ve sonucunda yapılacak olan testler, analizler, uyulması gereken standartlar belirlenmiş ve gerekli yapışma performans testleri gerçekleştirilmiştir. Sentezlenen kimyasallar ve hazırlanan karışımlar için gerekli spektroskopik, kalitatif ve kantitatif analizler yapılarak karakterizasyonlar gerçekleştirilmiştir. Yapılan çalışmalar sonunda literatürde ve teknikte daha önceki çalışmalarda çok az örneklerine rastlanan su bazlı, tek komponentli metal-lastik fiksatörlerinin hazırlanması gerçekleştirilmiş ve belli bir seviyede istenilen yapışma performansı sağlanmıştır. Hazırlanan; resorsinol, formaldehit, kauçuk içerikli hamur karışımı (LSH) ile metal yapışma tespit edilmiştir. Bu, konvansiyonel olarak kullanılan astar yapıştırıcı komponent ticari ürünlerle karşılaştırıldığında doğru bileşiklerinin ve bağlayıcıların seçilmesi, tasarlanması ile olumlu sonuçların ortaya çıkabileceği sonuçlarını ortaya koymaktadır.

In the related study, it is aimed to prepare the prescriptions of chemical mixtures used in the production of metal parts with rubber and applied to the surface of the metal, allowing the tire to adhere to this surface during the vulcanization phase. Rubbercoated metal parts produced by vulcanization method using elastomer paste are especially used in sectors such as automotive, defense, aviation and maritime. One of the most important reasons for their use in related sectors is that they are functional materials where the flexible structure of rubber-containing tires and the strength of metals are needed at the same time. Cleaning the metal surface is the first and most important stage of all processes. Contaminants that will prevent wetting of the primer formulation and disrupt the formation of strong covalent bonds across the interface, impurities from the metal's production stages, for example; It aims to remove impurities such as oil, grease, fingerprints from the surface. Basically, there are multiple cleaning models that can be applied. Covering and bonding metals with rubber helps to reduce and dampen vibration. The technology of bonding rubber to metal is the bonding of rubber to metal during vulcanization or bonding of vulcanized rubber products to metal. The function of the adhesive is to bond rubber and metal by wetting and creating interfacial contact at the molecular level through physical or chemical bonds. In order to obtain a reliable bond, single or double layer (primer, top coat primer) adhesive systems are used in unbaked rubber-metal bonding. Coating the different components is the first stage of bonding. Rubber-metal adhesion is basically based on chemical bonding mechanism or adsorption mechanism. In other words, adhesion occurs through molecular interactions between the two materials. Wetting both surfaces is essential to obtain homogeneous interfaces. Due to the simultaneous occurrence of many interactions during adhesion, the mechanism is difficult to elucidate. The formation of a homogeneous primer film must be achieved. It should spread easily on solid substrate. After all components have properly wetted the substrate surface, adhesion can be achieved homogeneously through chemical bonding, mechanical locking, and diffusion mechanisms. All these reactions must be carried out in a very short time for a strong bond to form. There are two parts of application in the adhesion of the mixture containing metal and rubber. First; primer (primer) and second layer adhesive application, and the other is a single layer application. The target in the designs of adhesive systems; The metal surface and the rubber surface contain materials to form strong and durable bonds. Adhesives are raw materials that have been used for a long time. While it was obtained naturally in the past, with the increase in technical demands, new derivatives have been developed and their strength and other properties have been improved. In recent years; Studies have been carried out on adsorption and generation of strong interfacial forces at the metal-adhesive interface. On the adhesion properties of elastomers; Studies such as improving its composition, increasing its performance, increasing heat resistance, regulating surface tension, drying in a short time and increasing its mechanical properties have been carried out. This study, which is presented in order to realize the production of related adhesive chemicals used in high quantities in our country and to contribute to our economy, has been planned. In the study, a working perspective has been created that reaches from factory production processes where the product is used in high quantities to field studies. It is aimed to develop new rubber-metal fixators that will provide more effective adhesion under more moderate conditions. In this context, it has been observed that the studies conducted to understand the mechanisms of fixation, substrate and primer bonding to the metal surface, or the clamping mechanisms of the secondary components that increase the bond strength were observed to be limited. In the processes where rubber is bonded on metal, the process steps were examined and studies were carried out sequentially, and new and different metal rubber adhesive mixtures were designed and tested by comparison with commercial ones. In the stages of the study; Determination of the metals to be used, preparation of the surfaces for adhesion, cleaning were carried out. Determination of the rubbercontaining mixture recipe to be used, supply of recipe raw materials and quality controls were made. By preparing the sample rubber-containing dough mixture in the mixer mixer, shaping the mixture was provided. Metal-rubber fixation was carried out by vulcanization of metal and dough by firing under certain conditions with vulcanization process. The tests, analyzes to be carried out in and as a result of all these intermediate processes, the standards to be complied with were determined and the necessary adhesion performance tests were carried out. The necessary spectroscopic, qualitative and quantitative analyzes were made for the chemicals synthesized and the prepared mixtures to be included in the adhesive mixture content, and characterizations were carried out. The adhesion qualities of the prepared original Rubber Metal Fixator (KMF) compared to Chemosil primer and adhesive components, which are used commercially at high rates in the sector, were compared. In order to achieve the desired results, studies were carried out by designing formulas in different structures from F1 to F7. The mixtures in all these formulas are supported by different polymeric and amine-containing structures. Comparison results were discussed according to the prepared formulas. At the end of the studies, water-based, one-component metal-tire fixators, of which very few examples were found in previous studies in the literature and technique, were prepared and the desired adhesion performance was achieved at a low level. Prepared; Metal adhesion was determined with the paste mixture containing resorcinol, formaldehyde and rubber. This demonstrates the results that positive results can occur with the selection and design of the right compounds and binders when compared to conventionally used primer adhesive component commercial products. For this purpose, it has been predicted that the primer adhesive formula, which is being used commercially, will be improved with chemicals at the last stage of the studies. In the F7 study, the commercially used Chemosil 211 was used as a primer, and the adhesive component was applied in different applications instead of the adhesive component Chemosil NL 222 with F7, which was prepared as a unique component, and their adhesion strengths were compared. A significant increase in adhesion strength was observed. This indicates that the formulation can be an intermediate binder in adhesion. In the formulations, it has been revealed that a suitable intermediate binder chemical may be in the form of the F7 formulation prepared as an example, but the part that binds to the metal surface as a primer should be developed by further studies in order to reach the potential of a commercial product. It may also be more original to create single-component formulations instead of the two-component formulations currently used here. However, it is necessary to understand the chemistry behaviors of the limiting effect to increase the selectivity of the chemicals fixed on the metal surface in the formula and to plan new academic studies in this direction.