Glikolüril, oligomerleri ve türevleri
Glycoluril, oligomers and derivatives
Yazar: ESRA TUNÇEL
Danışman: PROF. DR. NİLGÜN KIZILCAN
İstanbul Teknik Üniversitesi / Fen Bilimleri Enstitüsü / Kimya Ana Bilim Dalı
Derece: Yüksek Lisans, 2017
Konu: Polimer Bilim ve Teknolojisi = Polymer Science and Technology

Özet:
Bu çalışmada, glikolüril (asetilen diüre), üre, glioksal ve formaldehit reaksiyonu ile asidik ortamda üretilmiş ve daha sonra modifikasyonları sonucu glikolürilin oligomerleri ve türevleri sentezlenmiştir. Sentezlenen bu ürünler, poliüretan yapımında katkı malzemesi olarak ve poliolün yanmazlık özelliğini arttırıcı olarak kullanılmış ve yanmazlık özelliğini arttırıcı etkileri araştırılmıştır.
Glikolürilin, asidik ortamda paraformaldehit ile verdiği reaksiyon sonucu glikolürilin dimeri üretilmiştir. Glikolüril ve dimerini ayrı ayrı metanol varlığında formaldehit ve monoetanolamin ile reaksiyona sokarak, glikolüril türevleri elde edilmiştir.
Sentezlenen glikolüril, glikolürilin dimeri, glikolürilin monoetanolamin ve formaldehit ile reaksiyon ürünü ve glikolürilin dimerinin monoetanolamin ve formaldehit ile reaksiyon ürünü FTIR ve NMR ile yapı analizleri gerçekleştirilmiştir. Ayrıca erime noktası ve çözünürlük özellikleri tespit edilmiştir.
Elde edilen glikolüril,  glikolürilin monoetanolamin ve formaldehit  ile reaksiyon ürünü ve glikolüril dimerinin monoetanolamin ve formaldehit  ile reaksiyon ürünü poliüretan köpüklerin yapımında katkı maddesi olarak kullanılmıştır. Bu ürünler poliüretan köpük üretiminde poliolün %20'i oranında ortama katılmış, elde edilen poliüretan köpüğün özellikleri incelenmiştir. Bu amaçla Termal Gravimetrik Analizi (TGA) ve UL94 testine uygun testler kullanılmıştır. 
Poliüretanın elde edilmesinde kullanılan glikolüril bileşiklerinin azot içeriğinin yüksek olması ve çoklu halka içermesi poliüretana belli oranda yanmazlık sağlamaktadır. Glikolüril dimeri, glikolürilin monoetanolamin ile modifiye edilmiş türevi ve glikolüril dimerinin monoetanolamin ile modifiye edilmiş türevi hem yüksek oranda azot içerir hem de halka sayısı daha fazladır. Bu nedenle yanmazlığa katkısı daha fazla olması beklenir. 
Glikolüril, oligomerleri ve türevleri kısmen daha önce çeşitli bilimsel araştırmalar sonucunda sentezlenmiştir. Glikolürilin dimeri, monoetanolamin ve formaldehit ile asidik ortamda reaksiyonu ilk olarak yaptığımız çalışmalarda gerçekleştirilmiş, glikolürilin dimerinin monoetanolamin ile modifiye edilmiş ürünü elde edilmiştir ve yapılan FTIR ve NMR tetkikleri sonucunda beklenen pislerin gözlemlenmesi ile ürünün sentezinin başarılı olduğu ispatlanmıştır. Bunun yanı sıra poliüretanda yanmazlık özelliğini arttırıcı katkı maddesi ve poliolün yanmazlık özelliğini arttırıcı olarak glikolüril, oligomerleri ve türevleri ilk defa literatürde bizim yaptığımız çalışmalarda kullanılmış ve başarılı olduğu yapılan TGA ve UL94 tesitine uygun testlerle ispatlanmıştır.

Abstract:
In this study, glycoluril (acetylene diurea) is produced by reaction of urea, glyoxal and formaldehyde in acidic medium and glycoluril oligomers and derivatives are synthesized by glycoluril's modification. These synthesized products have been used in polyurethane as an additive and the effects of increasing the incombustibility have been investigated.
The commercial development of polyurethane first began in 1937 with Otto Bayer's investigation of the product polyol and diisocyanate reaction. Polyurethane is a very large and complex polymer. Typical polyurethane foam; Urethane bond, aromatic and aliphatic hydrocarbons, amide, ester, biuret, isocyanurate, carbodiimide groups. The most important thermosetting polymers are polyurethane foams. Besides polyurethane, diisocyanate and polyol group additives are also included. These additive materials are capable of inflating and deflating. The most commonly used fire retardant additives in polyurethane are aliphatic and aromatic phosphates.
Polyureas are polymers containing the urea group in the polymer chain. First synthesized by Wöhler in 1892. Melting point is between 50-100 ° C.
The condensation reaction of the diisocyanate with the polyurea diamine results in the end result.
The disadvantage of the system is that it requires an excessive amount of organic solvent to reduce the viscosity. UV resistance is good. Production is cheap. Strength is good. For this reason, demand in industrial areas is increasing day by day. It is used in ink, coatings and varnishes.
The fact that polyurethane materials can be produced with different qualities and characteristics, makes use of these materials constantly widespread. However, research and development of properties according to the place of use is also an important issue. The polyurethane materials are plastic based. Therefore, these materials are deteriorated when they are exposed to heat, as well as being weak in their resistance to burning. Therefore, it is necessary to carry out studies to develop these properties.
By adding fillers, the thermal and mechanical properties of polyurethane materials can be added, and more economical product production can be achieved by reducing the consumption of expensive raw materials. While one of the properties of polyurethane materials is being improved, other properties may be adversely affected. Therefore, it is very important to investigate and interpret the effect of additives and fillers on the mechanical, thermal and structural properties of polyurethane materials. As a filler material, it reveals the importance of the utility thesis to provide the polyurethane industry with fillers and additives which will not impair the mechanical properties of the polyurethane material, and which can improve it, besides can reduce the cost.
The reaction between urea and formaldehyde is complex. The combination of these two chemical compounds brings together three-dimensional networks as well as linear and branched polymers in the cured resin. The most important factors determining the properties of the reaction products are (1) the relative molar ratio of urea and formaldehyde, (2) the reaction temperature, and (3) the various pH values of the condensation. These factors influence the rate of increase in molecular weight of the resin. Thus, the properties of the reaction products vary considerably when lower and higher condensation steps are compared, in particular the solubility, viscosity, water retention rate and curing rate of the adhesive. All of these are largely dependent on the molecular weight. The reaction between urea and formaldehyde is divided into two stages. First; Alkaline condensation to form mono-, di- and trimethylololes (tetramethylolure is never isolated). The second step is the acid condensation of methylolureas; Are first soluble and then insoluble cross-linked resins. On the alkaline side, the reaction of urea and formaldehyde at room temperature causes the formation of methylolurenine. The end result of the condensation reaction is methylene-ether bonds between urea molecules.
Condensation products of glycoluril and glycoluril dimer with a mixture of formaldehyde and ethanol amine used as additive in the production of polyurethane in order to improve its fire resistance.
Glycoluril was first synthesized by Siemonsen in 1904 with glyoxal and urea reaction. Glycoluril formation probably proceeds in two steps: one molecule reacts with glyoxal, one molecule urea to form an intermediate compound, glyoxal monourein (4,5-dihydroxy imidazolidone); and this compound reacts with another molecule urea to form glycoluril. Glycolurils have been received a great attention due to their applications as a slow release nitrogen fertilizer, explosives, polymer crosslinking agents. Glycolurils are also important building blocks for both molecular and supramolecular chemistry   Particular attention has been turned to cucurbiturils which are intriguing macrocyclic compounds, whose skeleton is constituted by glycoluril ring moieties. Glycoluril oligomers were also synthesized before. Glycolurils are reacted with formaldehyde and primary amines to give ring structure.
First of all, we produced the glycoluril molecule. Urea was dissolved in water into the reaction flask and then 40 % aq. solution of glyoxal and concentrated HCl were added. The mixture was heated. After about 2 hours, a heavy precipitate had formed.  The reaction mixture was allowed to cool to room temperature and filtered. The filter cake was washed several times with water and then acetone.  The resulting white solid product of glycoluril was dried at 105 °C and then vacuum oven at 80 °C.
Secondly, glycoluril's dimer was produced. Glycoluril, paraformaldehyde and HCl were added into a reaction flask. The reaction mixture was raised to 50 °C for 48 hours.  The reaction mixture was cooled to room temperature and filtered. The solid product was washed several times with water and then recrystallized with TFA to yield glycoluril dimer as a white solid.
Synthesized products used to increase the polyurethane nonflammability, product formed by reaction with glycoluril, glycoluril ethanolamine and formaldehyde, product formed by reaction of glycoluril dimer with ethanolamine and formaldehyde.
The mixing ratio used in preparing all the foams;
One of glycoluril or glycoluril derivative products adds polyol and isocyanate.
Commercial polyol (creosol polymix) was used as polyol during polyurethane construction, PMDI as isocyanate was used. First, 2.5 g of the product we synthesized are pulverized and then put into 12.5 g of polyol and mixed thoroughly. This mixture was added with 19 g of isocyanate component and stirred rapidly for 8 to 9 seconds. The resulting polyurethane foam is expected to swell and solidify.
As a result of the reaction of glycoluril and paraformaldehyde in acedic medium, glycoluril's dimer was produced. Glycoluril and its dimer are reacted separately with formaldehyde and monoethanolamine in the presence of methanol to obtain glycoluril derivatives.
After all, we produced glycoluril's monoethanolamine modification and glycoluril's dimer's monoethanolamine modification. Glycoluril, formaldehyde as formaline and methanol were added into a reaction flask.  The reaction mixture brought to reflux while stirring with a magnetic stirring. A solution of ethanol amine in methanol was added slowly dropwise (over 1 h) to the mixture. The refluxing continued for 48 h. The solid reactant was completely dissolved in reaction mixture. Then, precipitate had formed.  The precipitate was washed several times with methanol.  The resulting white solid product (GLI EA) was dried at 105 °C and then vacuum oven at 80 °C. Therefore, glycoluril dimer, formaldehyde as formaline and methanol were added into reaction flask.  The reaction mixture brought to reflux under magnetic stirring. A solution of ethanol amine in methanol was added slowly dropwise (over 1 h) to mixture. The reaction mixture was refluxed for 48 hours. The solid reactant was partly dissolved in the reaction mixture then, white product precipitated.  The product (GLI-D EA) was washed several times with methanol.   
Structural analyzes were carried out of synthesized glycoluril, the reaction product of glycoluril with monoethanolamine and formaldehyde and the reaction product of glycoluril's dimer with monoethanolamine and formaldehyde by FTIR and NMR. Melting point and solubility characteristics are also determined.
The obtained glycoluril, the reaction product of glycoluril with monoethanolamine and formaldehyde and the reaction product of glycoluril dimer with monoethanolamine and formaldehyde are used as an additive in the production of polyurethane foams. These products are added to 20% of polyol in the production of polyurethane foam, and the properties of the obtained polyurethane foam are examined. Thermal Gravimetric Analysis and UL94 test are used for this purpose.
Glycoluril compounds used in the production of polyurethane have a high nitrogen content, and the multi-ring provide certain flammability to polyurethane. The glycoluril dimer and its monoethanolamine modified derivatives both contain high nitrogen and have a higher number of rings. Glycoluril's dimer, derivative of modified with monoethanolamine of glycoluril, and derivative of modified monoethanolamine of glycoluril's dimer contain both high nitrogen and higher number of multi-rings. For this reason, it is expected that the contribution to the incombustibility is higher.
The compounds used in the modification of polyurethane are readily available and cheap materials such as urea, formaldehyde and monoethanolamine. The physical properties of the incombustibility have changed according to the type of compound used in the modification. It has been found that the modified compounds have a positive effect on the polyurethane impregnation.
Glycoluril, oligomers and their derivatives have been used for the first time in the literature for polyurethane synthesis and the effect of incombustibility has been investigated. When only 8% of glycoluril, oligomeric and derivatives were used in the total polyurethane mass, TGA analyzes showed that after combustion polyurethane foams left 40% by weight of residue.
It is also a current study to determine how the additives used for retarding combustion in polyurethane materials cause a change in mechanical properties as well as combustion delay effects.