Hintyağı temelli vinil tipi makromonomerlerin sentezlenmesi ve polimerizasyonu

ÖZET Hintyağı, yaklaşık % 90 oranında risinoleik asit içeren bitkisel bir yağdır. Risinoleik asit, zincirinde bir hidroksil grubu ve bir çift bağ bulunması nedeniyle, hintyağı çok sayıda reaksiyon verme özelliğine sahiptir ve bunun sonucu olarak da geniş kullanım alanına sahiptir. Bununla beraber hintyağı kurumayan bir yağ olduğu için yüzey kaplayıcılarda kullanımı sınırlıdır. Bu çalışmada, hintyağının keten yağı ile interesterleşme reaksiyonundan elde edilen ara ürüne vinil grupları sokularak yüksek molekül ağırlıklı makromonomer sentezlenmiş ve bunun homopolimerizasyonu ve stiren monomer ile kopolimerizasyonu gerçekleştirilmiştir. Sonuçta elde edilen homopolimer ve kopolimer örneklerinin organik yüzey kaplayıcı malzeme olarak kullanımları yönünden film özellikleri tespit edilmiştir. SUMMARY Castor oil is a vegetable oil that contains approximately 90 % ricinoleic acid. Because of having a hydroxyl group and a double bond of ricinoleic acid in the backbone, castor oil has the ability of esterification and dehydration reactions. So that castor oil is used for manufacturing of industrially valuable materials. Nevertheless its usage in coating materials is limited because of being a non-drying oil. Fortunately, if castor oil is dehydrated, because of forming of conjugated double bonds, it gains drying property. It is also possible to obtain a synthetic oil having drying property by esterification of the secondary esters of castor oil with drying fatty acids. Another method that can be applied to obtain products having useful properties, is decomposition of the secondary esters of castor oil. In this process conjucated double bonds are formed on ricinoleic acid backbone. Therefore, it is possible to prepare synthetic drying oils with conjugated double bonds from the decomposed intermediate product. Drying and semi-drying oils are widely used in modification of natural or synthetic resins as surface coating materials. Paints, varnishes, and other decorative and protective coatings, including alkyd resins, lacquers, and printing inks are manufactured in huge quantities and they constitute one of the major fields of oil and fat utilization. Although the natural oils have been used for thousands of years as binders for coatings, without chemical modification beforehand they are nowadays used only to a small extent. Slow drying, sensitivity to hydrolysis and inadequate corrosion prevention properties are responsible for this fact. For improving their properties as binders, various methods have been used for their modification. The well known method is the copolimerization of oils with vinyl monomers such as styrene. Natural oils can be subjected to free radical copolymerization with vinyl compounds. The usual peroxide catalysts and heat are employed.The principle reaction is probably the grafting of vinyl polymer chains onto the fatty acid residues of the oil. The vinyl compounds commonly used in addition to styrene are vinyl toluene, divinyl benzene, methyl methacrylate and acrylic acid. In the conventional process, the number and the position of double bonds in the oil structure are important. With oils including conjugated double bonds the reaction takes place very rapidly even without using initiator, but with oils including isolated double bonds, it is relatively slow and it can be controlled and an initiator such as benzoyl peroxide is needed. 45