Theses supervised by Prof. Dr. Nilgün Kızılcan
10 theses · İstanbul Technical University
Akrilik emulsiyon polimerlerinin sentezi ve boya formülasyonunda kullanımı
Formed on the metal surface from corrosion due to the atmospheric conditions, causes the loss of the mechanical properties of the metal, reduce the lifespan and seriously affect the country's economy. For these reasons, metals have to be protected against atmospheric conditions. One of the precaution methods is isolated metals from water and air with a coating material. Solvent-based system is the leader of the metal coatings, but recently solvent-based product usage limitations and volatile organic compounds (VOC) regulations make popular water based coating for protection of metal. For that matter, solvent based products usage, which have negative effect on human health and environment because of toxic and flammable material inside can be reduced with water-based products. With the project, emulsion polymers performance which has ketonic resin as a co-binder will be tested on water based metal paint to evaluated corrosion and adhesion properties. Ketonic resins can be added to the emulsion polymer to prolong coating life because it increases adhesion and corrosion performance. Ketonic resins are the family of thermoplastic resins and have low moleculer weight. They work as an adhesion promoter when combine with co-polymers. Cyclehexanone formaldehyde resin is used in this thesis because of high amount –OH functional group in its backbone. It gives better compability with water borne systems. Choosing right polymer is one of the important criteria for corrosion protection. Emulsion polymerization system is can be used in the metal corrosion. 2-Ethylhexyl acrylate and methyl methacrylate can be choosen for polymerization due to their hard monomer properties. Cyclehexanone formaldehyde resin is obtained solid state and it dissolved in proper solvent. This emulsion is added on pure acrylic polymer which, obtained from water based emulsion polymerization method, as 5% rate and tried to getting homogeneous blend under high-speed mixture. Acrylic polymer – ketonic resin blend is used for water-based metal coating formulation. Water based metal paint is applied on 4 different metal types such as aluminum, galvanized, stainless steel and cold rolled steel for checking adhesion and corrosion performances. The aim of the study is evaluating ketonic resin adhesion and corrosion performance on metal formulation with comparing ketonic resin-acrylic polymer combination and pure acrylic polymer emulsion without ketonic resin. For this study, 3 different paint is prepared one is has only pure acrylic polymer as a binder, second one is acrylic polymer – ketonic resin blend and last one is commercial product of ketonic resin is blended with acrylic polymer as a binder and cheching performance between 3 of them. According to adhesion and corrosion performances show that ketonic resin is enhance adhesion on some metal types: adhesion affects corrosion performance in long term. During the synthesis part, when added ketonic resin on the system, some stability problem is observed. Although added some surfactant into the system for preventing agglomeration, is not clear off the problem. Preventing the system against to stability problem, resin will be connected with acrylic polymer as chemical bond during the polymerization stage and than they are tested on paint formulation is planned for next study. In this way, foreseeing that ketonic resin will be integrated the acrylic emulsion polymer and getting better adhesion and corrosion performances.
Pirina kompozit reçine sentezi
In this study melamine-formaldehyde, urea-formaldehyde and melamine-urea-formaldehyde resins which are thermoset amino resins are modified with olive pomace which is a natural product. Olive pomace, which is taken from Edremit region of Balikesir/Turkey, which has been a waste of olive industry and has been used as fuel or fertilizer by local farmers. The aim of this study is to utilize olive pomace in industry by modifying the amino resins which are synthesized at basic environment with olive pomace. Therefore, resin will be more lightweight, cheaper and will have a wood-like appearance. This study consists of two parts. First part is the synthesis of melamine-formaldehyde and urea-formaldehyde resins which are classified as thermosetting amino resins and their pomace composites. The desired Formaldehyde/Melamine and Formaldehyde/Urea molar ratios are 2 and the synthesis reactions takes place at basic environment. To make a wood-like resin-pomace composite, resins are in situ modified with olive pomace while they are synthesized. The weight of pomace is determined as 10%, 20% and 50% of the weight of melamine and urea in melamine-formaldehyde and urea-formaldehyde resins respectively. In the second part a combination of melamine and urea is used. Melamine-urea-formaldehyde resin is synthesized with a pomace amount of 20% of the total weight of melamine and urea. Resins are characterized using Fourier Transform Infrared Spectroscopy. Water absorption percentage, solubility in water and solubility of in organic solvents are determined. They are resistant to solvents, they either insoluble or slightly soluble. They have wood-like appearance as intended. Moreover, they have different characteristics based upon olive pomace ratio. In low olive pomace weight ratios colour of the composites are light and it gets darker as olive pomace ratio increases. Also, in low olive pomace weight ratios composites are hard and rigid while in higher olive pomace ratios they become softer and sticky. They all have homogeneous appearance which makes them suitable for direct use in many applications.
Fonksiyonel amin bileşikleriyle modifiye ketonik reçine sentezi
α – Hidrojen içeren ketonlar ile aldehitlerin reaksiyonundan ketonik reçineler elde edilir. En çok kullanılan ketonik reçine termoplastik siklohekzanon-formaldehit reçinesidir. Diğer polimerler ile karşılaştırıldığında daha düşük molekül ağırlığına sahip siklohekzanon-formaldehit reçinesi, tek başına kullanılmayıp diğer polimerik maddeler ile karıştırılarak yüzey kaplama, vernik, mürekkep, kâğıt sektöründe katkı maddesi olarak kullanılırlar. Son yıllarda siklohekzanon-formaldehit reçinelerinin farklı reaksiyon koşulları ve değişik modifiye edicilerle in situ ve sonradan modifikasyonları yapılarak, siklohekzanon-formaldehit reçinelerinin kimyasal fonksiyonalitesini arttırmaya yönelik çalışmalar ön plana çıkmıştır.Bu çalışmada siklohekzanon ile formaldehitin bazik ortamda ve ısı kataliziyle polimerizasyonugerçekleştirilmiştir. Değişik siklohekzanon-formaldehit mol oranlarında; siklohekzanonun α-hidrojenleri üzerinden dietanolamin, sikloüre bileşikleri ve glikolamin bileşikleri ile in situ ve sonradan modifiye reçineler elde edilmiştir. Bu yöntem ile elde edilen bileşiklerin fonksiyonelite içermeyen sikloheksanon-formaldehit reçinelerine göre farklı özellikler gösterdiği, oranlarına bağlı olarak oluşturulan reçinelerin kimyasal ve fiziksel yapılarında farklılıklar olduğu gözlemlenmiş, gözlemlenen değişimler spektroskopik yöntemler vasıtasıyla belirlenmiştir. Elde edilen reçinelerin çözünürlük, FTIR, NMR ve erime noktası analizleri yapılarak reçinelerin özelliklerinde meydana gelen değişimler incelenmiştir. Yapılan incelemelerden yola çıkılarak üretilen reçinelerin muhtemel yapıları belirlenmiştir. Bu reçinelerin muhtemel yapıları çizilerek, belirtilen yöntemlerle ispatlanmıştır. Yapılan çalışmalar ile elde edilen bileşiklerin endüstriyel uygulanmasını sağlamak amacıyla, endüstriyel olarak kullanım alanı oldukça geniş olan poliüretan bileşiğinde kullanımı ve bu bileşikler kullanılarak elde edilen poliüretan bileşiklerinin kimyasal ve fiziksel değişimlerini, katkı maddesi olarak kullanımında oluşacak üründeki değişimlerin neler olduğu incelenecektir. Oluşan ürünlere katışmış olan miktar bazında yapılan çalışmalar içinden en uygun olan ürün bulunarak uygulanan miktarın optimizasyonu sağlanmıştır. Bu değerler içerisinde kütlece %20'lik madde eklemek polimer içerisinde maksimum fiziksel ve kimyasal etki gözlemlenmesine neden olmuştur denilebilir.Bu nedenle yapılan çalışmalarda kullanılan miktarın bu olacağı söylenebilir.İçeriğinde ki azot miktarı çeşitli yöntemlr vasıtasıyla ölçülerek miktarın en uygun oranı yanma miktarına bağlı olarak tespit edilecek ve yapılan çalışmalar neticesinde elde edilen ürünler farklı koşul ve reaktanlar varlığında testlere tabi tutulacaktır.Burada ki en önemli etkenlerden biride oluşturulan polimerlerin asıl yapılarını tayini için kullanılan yöntemler ile elde edilen polimerlerin tespitidir. Bu nedenle yapılan çalışmalar sonucu verilen sonuç ürünlerin azot miktarları tayin edilerek moleküler yapıda ne kadar azot içerdiğine bağlı olarak yapısal formülasyonlarının ne olduğuna karar verilebilmektedir. Bu noktada elde edilen bileşiklerin NMR spektrumlarında pik oranları baz alınabilir. Bulunan bileşikler belirli oranların üzerinde olup olmadıkları ve bu oranların molekül içinde nasıl dağıldıklarını tespit ederek yapılan çalışmanın asıl amacı olan polimerlerin üretimi ve tespiti konusunda sonuçlar başarılı elde edilmiştir.Endüstriyel anlamda kullanılan bileşiklerin içerisinde bu reçinelerin kullanımı ve bu polimerler içinde bulundurulması ile yanmazlık sağlama ise farklı bakış açıları getirmektedir. Yapılan çalışmalar göstermiştir ki bu gibi bileşiklerin polimerler içerisinde farklı oranlarda kullanımı polimerin yapısal özelliklerini değiştirebilmektedir.Bu nedenle elde edilen sikloüre bileşikleri ve bu bileşiklerden elde edilen reçineler daha sonrasında poliüretana uygulanıp fiziksel ve kimyasal stabilitesi, bu maddelerin azot miktarı artışına göre yanmazlık artış oranları incelenecektir.
Kompozit resol reçinelerinin sentezi ve cam elyaf üretiminde kullanımı
This study can be divided into two parts. The first part aims to synthesis resol nanocomposites that can be used for thermal insulation materials, coatings, molding compounds, foundry materials, wood products and aerospace components due to their high strength, thermal stability, heat resistance and solvent resistance. In this study, resol resins were modified with alendronic acid and sepiolite in the presence of base catalyst. Sepiolite is a needle like clay that improves the thermal stability, mechanical properties of polymers and used in the matrix of polyethylene, polypropylene, polyurethane, polyamide, polyvinylalcohol and epoxy resins, however there is not any research that include sepiolite and resol. Alendronic acid that is a phosphorus compound mostly used in drug sector for treatment of hypercalcemia, Paget's disease, parasitic diseases, hypercholesterolemia and atherosclerosis. On the other hand phosphorus containing compounds used as flame retardant materials in engineering plastics, polyurethane foams, phenolic resins, polyamides, coatings and textiles. The influence of sepiolite content and alendronic acid content on spectroscopic, thermal and microscopic properties of resins have been researched and determined. For this reason, with adding the different clay amounts of sepiolite (3wt%, 5wt%, 8 wt%, 10wt%, 15wt%, 20 wt%, 30 wt% and 50wt%) and different amounts of alendronic acid (5wt% and 10wt%) were synthesized. Furthermore, the synergist effect of sepiolite and alendronic acid were studied with 5wt% sepiolite and 5wt% of alendronic acid. In this part the synthesized resins formed the structure of nanocomposites. The characterization of the resin nanocomposite samples have been researched and determined. The characterization of the resin samples were performed by Fourier Transform Infrared Spectroscopy (FTIR-ATR), Thermogravimetric Analysis (TGA), X-ray Diffraction (XRD) and Scanning Electron Microscope (SEM). In addition, the solvent behaviour of these resins were investigated with the solvents of acetone, methanol, tetrahydrofuran (THF), dimethylformamid (DMF), chloroform and dimethyl sulfoxide (DMSO). In FTIR-ATR measurements, with the characteristic peaks of neat resol (PFR), Si-O-Si vibrating characteristics of sepiolite and phosphorus peaks of alendronic acid were obtained in nanocomposite resin samples. The DSC technique was used for determining the maximum cure temperatures and onset of cure temperatures. The cycle was heated from 30°C to 200°C with 10 °C/min heating rate. Due to sepiolite clay and alendronic acid loading, the curing temperarutres were enhanced. The thermal attitude of resins were determined by TGA analysis. All resin samples heated at linear heating rate of 10 oC/min up 30oC to 700oC temperature. The weight loss of the resins were calculated with TGA. The obtained all residues at 700oC were higher than 50%wt of initial resin. The structures and the variations of spacing of the PFR, SEP, PFR-AAs, PFR-SEPs and PFR-AA-SEP were detected by X-ray diffraction. The d-spacings were calculated by Bragg's Equation. All of the PFR-SEPs exhibited intercalated structure. As the loading of sepiolite was increased, the interlayer distance did not change very much due to the layers of sepiolite were bonded covalently and resol has thermoset structure even before curing. In PFR-AAs the nanocomposite structure was changed from exfoliated to intercalated with increasing alendronic acid content. Distribution of clay particles in polymeric resol resin matrix and morphology of resin samples were determined with SEM analysis. The sample that contained 10wt% sepiolite loading had good dispersion in resol matrix that supports the strong interaction between silanol (Si-OH) groups of sepiolite and methylol (-CH2OH) groups of resol. The solubility tests were done with six different solvents that were acetone, methanol, THF, chlorofom, DMF and DMSO. All of the resin samples were not solve in acetone, methanol, THF and chloroform. The neat PFR were soluble in DMF and DMSO. Alendronic acid including nanocomposite resins were soluble in DMF however sepiolite including nanocomposite resins were not soluble in DMF. In DMSO not only PFR-AAs but also most of PFR-SEPs and PFR-AA-SEP were soluble. However, increased sepiolite contents of PFR-SEPs reduced the solubility. The second part of this study aimed to obtain production of glass wool insulation materials with sepiolite and alendronic acid modified phenol formaldehyde resol resins to improve thermal properties. Glass wool that is a fluffy material of discontinuous fibers in random lenghts is very useful in thermal insulation sector. For producing glass wool composites of resol samples in a batch mixer the major ingredients (silica sand, limestone, soda ash, cullet) were blended at 1100oC-1300oC. From the reactor the molten glass was poured into the spinner that consisted of 2000 small holes. The fluid mixture were constrained and fibers were manufactured, owing to the centrifugal force of spinner. To bind glass wools the synthesized liquid nanocomposite resol resins were sprayed. After this step, the glass wool was dried in the curing oven at 180-250oC to obtain composite glass wool – modified resol resin product. Length and width trimmers were cut the size of the composite glass wool insulation product At the end of process glass wool composites gained the colour of resin samples.
Çitosan/polipirol/kil nanokompozitlerinin sentezi ve karakterizasyonu
Many researchers studying on discovering new materials to enhance the quality of human life in all aspects. The challenging part of this quest is to find all desired properties in a single material. A composite material is composed of two or more constituents to unite all desired properties in one material. The goal of this study is to discover and produce a high conductivity nanocomposite which is biodegradable, biocompatible, and biofunctional so that it can be used in biomedical applications. Chitosan (CS) is chosen as one of the most attractive polymer due to its' specific properties; such as biocompatibility, biodegradability, and biofunctionality, etc. One of the most investigated conducting polymers is polypyrrole (PPy) because of its characteristics such as; easy synthesis and high conductivity. Recently, there have been many attempts to synthesize composites of CS and PPy to investigate what combined functionality can be obtained. Combination of pyrrole with cerium (IV) ammonium salts (Ce+4) exhibits better solubility than PPy. In aqueous media, redox systems of Ce+4 and reducing agents such as acids are well known initiators for vinyl polymerization. Polymerization reaction in aqueous media has many technical advantages than other methods. Additionally, the preparation of polymers with clay minerals has been extensively studied topic due to understand the synergistic effect of them. In this work, Chitosan/Polypyrrole composites and Chitosan/ Polypyrrole/ Sepiolite (Cs/PPy/Sep) Nanocomposites (NC) were synthesized via redox polymerization in aqueous media with magnetic stirrer system in presence of ammonium cerium (IV) nitrate (Ce+4) at room temperature. The roles of the oxidant/monomer mole ratio, on the yield, conductivity and morphology of the resulting products were investigated. Chitosan /Polypyrrole composites and Chitosan/ Polypyrrole/ Sepiolite Nanocomposites (Cs/PPy/Sep NC) were prepared with the oxidant to pyrrole mole ratios as 0.67:1, 0.8:1, and 1:1 for comparison. In addition, to understand the effect of inorganic agents to Cs/PPy/Sep nanocomposites, Silver (Ag) ions were added to blend. Ag particles has some unique characteristics increased optical, electromagnetic, and catalytic properties. The yield and electrical conductivity of the products (polymer) were investigated as physical characteristics. The electrical conductivities of Cs/PPy/Sep NC were determined by four point probe technique. In addition, the resulting NC were characterized with spectroscopic method that was Fourier Transform Infrared Spectroscopy (FTIR), and also morphological method, which was Scanning Electron Microscopy (SEM). According to conductivity results, Polypyrrole/Chitosan (PPy/CS) composite polymers showed conductivity between 1.8x10-6 and 1.4x10-2 S/cm. Polypyrrole-Chitosan/Sepiolite (Ppy-CS/Sep) nanocomposite polymers showed conductivity between 3.0x10-4 and 6.41x10-4 S/cm. Polypyrrole/AgNO3 nanocomposite polymers had a conductivity between 0.755 and 7.2 S/cm. According to SEM results, PPy/CS-1 sample has average size of 28.90 nm and PPy-CS/Sep-1 sample has average size of 28.63 nm. In future, many applications will benefit from conductive materials like PPy/CS, PPy-CS/Sep and PPy/Ag in biosensors, bioactuators and many other biomedical applications which will be very important in next century.
Köpük poliüretan için yanma geciktirici poliol olarak kil modifiye nanokompozit ketonik reçineler
Cyclohexanone formaldehyde resin is modified with clays, which are sepiolite and montmorillonite, and alendronic acid which contains of phosphate group in its structure. The modified resins are added to rigid foam polyurethane for fire retardancy.
Pirol ve türevlerini içeren polimerler sentezi
Tez çalışmasında pirol içeren çeşitli polimerler sentezlenerek elektriksel iletkenlik, verim ve işlenebilirlik özelliklerinin geliştirilmesi hedeflendi. Polimerlerin sentezinde kimyasal ve elektrokimyasal yöntem kullanılarak toz ve film şeklinde ürünler elde edildi. Kimyasal yöntemde reaksiyon ortamı, reaksiyon sıcaklığı ve süresi, yükseltgen cinsi, yükseltgen/monomer oranı ve dopant varlığı gibi parametrelerin ürün özelliklerine etkisi araştırıldı. Pirol potasyum persülfat, demir(III) ve seryum(IV) tuzları gibi inorganik yapılı yükseltgenler veya yükseltgen karışımları varlığında polimerleştirildi. Pirolün susuz ortamdaki polimerleşmesini geliştirmek amacı ile organik esaslı yükseltgenlerden seryum(IV) oksi dibenzoat (CODB) ve feniliyodür(III) bis(trifloroasetat) (PIFA) kullanıldı. Bu yükseltgenler, toluen ve diklorometan gibi aprotik çözücüler içerisinde polipirol sentezine imkan sağladı. Herhangi bir dopant kullanılmadan polipirol için, PIFA varlığında 5–10-3 S/cm ve CODB varlığında 1–10-2 S/cm iletkenlik değerleri elde edildi. Çeşitli yükseltgenlerin varlığında gerçekleştirilen reaksiyonların sonucunda iletkenlik değerleri 10-4–100 S/cm olan polipiroller üretildi. Pirolün ketonik reçineler, poli(dimetilsiloksan), poli(etilen glikol) ve türevi ve metil akrilat ile kopolimerleri kimyasal yöntem ile sentezlendi. Kopolimerlerin verim ve iletkenlik değerleri, morfolojik ve ısıl özellikleri incelendi. İletkenlik değerleri 10-5–10-1 S/cm olan kopolimerler elde edildi. Polipirol/poli(dimetilsiloksan) kopolimerlerinin sentez ortamında, ağırlıkça yüzde 4 kil/pirol oranı ile, Na-montmorillonit ve organomodifiye Na-montmorillonit killeri varlığında nanokompozitler hazırlandı. Hidroksil grupları taşıyan ketonik reçinenin 2–tiyofen karbonil klorür ile esterleşme reaksiyonu sonucunda tiyofen uç gruplu modifiye reçineler elde edildi (CFTh2R ve CFTh4R). Modifiye reçineler ile pirolün kopolimerleri demir(III) klorür varlığında sentezlendi. Elektrokimyasal yöntem kullanılarak, modifiye CFTh2R ve CFTh4R reçinelerinin pirol ve tiyofen ile ayrı ayrı kopolimerleri sentezlendi. Kaplamaların H2SO4 ve NaCl çözeltilerinde korozyon davranışları incelendi ve uygulamalar için uygun olduğu belirlendi.
Keton/aldehit reçinelerinin mürekkep hazırlanmasında kullanımı
Bu çalışmada Türkiye ve Dünyada flekso ve rotogravür baskı sistemlerinde kullanılan solvent bazlı matbaa mürekkeplerinin ham maddelerinden olan, ticari kodla satılan ancak kimyasal yapısı bilinmeyen ketonik reçinenin NMR, FT-IR, DSC analizleri yapıldı. Elde edilen sonuçlara göre siklohekzanon formaldehit reçinenin özelliklerine benzerlik gösterdiği anlaşılmıştır. Siklohekzanon formaldehit reçinesi sentezlendi. Sentezlenen siklohekzanon formaldehit reçinenin FT-IR, NMR analizleri yapılmıştır. Mürekkep ve boya endüstrisinde ketonik reçine ile parlaklık, adhezyon, pigment ıslatıcılığı gibi alanlarda paralel görevde kullanılan teknik bilgi formunda aldehit reçine olduğu belirtilen Laropal A81'in NMR ve FT-IR analizleri yapılarak, laboratuarda sentezlediği siklohekzanon formaldehit reçinesi ve ticari olarak satışı yapılan ketonik reçineden mürekkep verniği ve mürekkep hazırlanmış ve standart testleri yapılarak performans karşılaştırılmaları yapılmıştır. Reçinelerin mürekkep üretiminde kullanılabilmesi için baskı sistemine uygun özellik gösterebilmeleri gerekmektedir. Bunun için reçinelerin çeşitli solventlerde çözünmesi incelenmiştir. Ayrıca, vernik testinde, %50lik reçine ve Izo propil alkol çözeltileri hazırlanarak, çözünürlük hızları incelenmiştir. Hazırlanan verniklerin ASTM standartlarına göre, D1200-10 viskozite, D523 parlaklık, F 2496 çizilme, D3359-97 adhezyon testleri yapılmıştır. Solvent bazlı flekso ve rotogravür mürekkeplerinde ana bağlayıcı olarak Nitro selüloz (NC) veya poliamid (PA) reçine kullanılır. Keton aldehit reçineleri performans arttırıcı katkı reçinesi olarak kullanılır. Laropal A 81'in mürekkep formülasyonunda ticari ketonik reçine ve deneysel olarak üretilen CFR ile kıyaslaması yapılırken, poliamid bazlı mürekkepler tercih edilmiştir. ASTM standartlarına göre, adezyon, viskozite, çizilme ve parlaklık testleri yapılmıştır. Sonuç olarak, ticari olarak ülkemizde mürekkep sektöründe tüketilen UK 100/500 keton reçinenin, siklohekzanon formaldehit reçine olduğu tespit edilmiştir. Üretilen CFR 'nin endüstriyel analizlerinde, ticari reçine ile viskozite dışında farklılık olmadığı tespit edilmiştir. Sentezlenen reçine, viskozite düşüklüğünden dolayı, daha çok flekso baskı sırasında mürekkep viskozitesini düşürücü amaçla kullanılan vernik üretimi için uygundur. Diğer yandan Laropal A 81'in ketonik reçineye göre çizilme direncinin daha iyi, parlaklığının ve viskozitenin daha düşük olduğu tespit edilmiştir. Böylece, sentezlediğimiz ketonik reçinenin ve piyasadaki rakiplerinin solvent bazlı flekso mürekkeplerindeki görev ve fonksiyonları incelenmiştir.
Bor içeren metil etil keton formaldehit reçinelerinin sentezi ve karakterizasyonu
Methyl ethyl ketone formaldehyde resins are modified in situ and after the polymerization with different modifiers to increase their physical and chemical performances by changing their chemical structures. In this thesis study, methyl ethyl ketone formaldehyde resins including nitrogen and/or boron are synthesized and their phycical and chemical properties are analyzed in a comperative way. The resins are prepared by alkaline-catalysed condensation of methyl ethyl ketone and formalde in a molar ratio of 1: 2 in a batch process. NaOH is used as catalyst for this reaction. During all of the reaction pH value should been kept around 10-11. The medium is kept at 80-90oC. After 4h, the reaction is completed, and yellow resin is formed. For in sitı modifications, the modifer is added to the reaction medium in the beginning of the reaction. For boric acid modification, of resin sample is dissolved in toluene, and boric acid is added. Using deanstag systam, the medium is heated to 150oC, refluxed for about 2h until no water is collected any more. Ten different types of methyl ethyl ketone formaldehyde resins are synthesized for this study, five of which include nitrogen, one includes boron and three include both nitrogen and boron: methyl ethyl ketone formaldehyde resin (MEKFR), MEKFR modified with alendronic acid at a ratio of 5wt% (MEKFR-AA), MEKFR modified with cyclic urea which is synthesized from alendronic acid at a ratio of 5wt% (MEKFR-CUAA), MEKFR modified with diethanolamine at ratios of 5wt%, 10wt% and 20wt% (MEKFR-DEA), MEKFR and three MEKFR-DEA modified with boric acid (MEKFR-BA and MEKFR-DEA-BA, respectively). After the synthesis and modifications of resins, their chemical structures are analyzed, and Fourier Transform Infrared Spectroscopy (FTIR) and Nuclear Magnetic Resonance Spectroscopy (NMR) are used for this purpose. When the spectums of resins obtained are looked through the characteristics peaks and their corresponding functional groups, it is concluded that the estimated chemical structures as the product of synthesis and modification reactions match with the results obtained. In the terms of physical properties, solubility analyses are carried out in five different solvents, namely ethanol, acetone, dichloromethane (DCM), tetrahydrofuran (THF) and dimethylsulfoxide (DMS), and it is seen that depending on the modifier type and ratio, the solubility of resins change, as a result of the changes in the chemical structures. Lastly, in order to get information about thermal behaviour of the resins and effects of modifications on thermal degradation of them, thermogravimetric analyses (TGA ) and Methyl ethyl ketone formaldehyde resins are modified in situ and after the polymerization with different modifiers to increase their physical and chemical performances by changing their chemical structures. In this thesis study, methyl ethyl ketone formaldehyde resins including nitrogen and/or boron are synthesized and their phycical and chemical properties are analyzed in a comperative way. The resins are prepared by alkaline-catalysed condensation of methyl ethyl ketone and formalde in a molar ratio of 1: 2 in a batch process. NaOH is used as catalyst for this reaction. During all of the reaction pH value should been kept around 10-11. The medium is kept at 80-90oC. After 4h, the reaction is completed, and yellow resin is formed. For in sitı modifications, the modifer is added to the reaction medium in the beginning of the reaction. For boric acid modification, of resin sample is dissolved in toluene, and boric acid is added. Using deanstag systam, the medium is heated to 150oC, refluxed for about 2h until no water is collected any more. Ten different types of methyl ethyl ketone formaldehyde resins are synthesized for this study, five of which include nitrogen, one includes boron and three include both nitrogen and boron: methyl ethyl ketone formaldehyde resin (MEKFR), MEKFR modified with alendronic acid at a ratio of 5wt% (MEKFR-AA), MEKFR modified with cyclic urea which is synthesized from alendronic acid at a ratio of 5wt% (MEKFR-CUAA), MEKFR modified with diethanolamine at ratios of 5wt%, 10wt% and 20wt% (MEKFR-DEA), MEKFR and three MEKFR-DEA modified with boric acid (MEKFR-BA and MEKFR-DEA-BA, respectively). After the synthesis and modifications of resins, their chemical structures are analyzed, and Fourier Transform Infrared Spectroscopy (FTIR) and Nuclear Magnetic Resonance Spectroscopy (NMR) are used for this purpose. When the spectums of resins obtained are looked through the characteristics peaks and their corresponding functional groups, it is concluded that the estimated chemical structures as the product of synthesis and modification reactions match with the results obtained. In the terms of physical properties, solubility analyses are carried out in five different solvents, namely ethanol, acetone, dichloromethane (DCM), tetrahydrofuran (THF) and dimethylsulfoxide (DMS), and it is seen that depending on the modifier type and ratio, the solubility of resins change, as a result of the changes in the chemical structures. Lastly, in order to get information about thermal behaviour of the resins and effects of modifications on thermal degradation of them, thermogravimetric analyses (TGA ) and Methyl ethyl ketone formaldehyde resins are modified in situ and after the polymerization with different modifiers to increase their physical and chemical performances by changing their chemical structures. In this thesis study, methyl ethyl ketone formaldehyde resins including nitrogen and/or boron are synthesized and their phycical and chemical properties are analyzed in a comperative way. The resins are prepared by alkaline-catalysed condensation of methyl ethyl ketone and formalde in a molar ratio of 1: 2 in a batch process. NaOH is used as catalyst for this reaction. During all of the reaction pH value should been kept around 10-11. The medium is kept at 80-90oC. After 4h, the reaction is completed, and yellow resin is formed. For in sitı modifications, the modifer is added to the reaction medium in the beginning of the reaction. For boric acid modification, of resin sample is dissolved in toluene, and boric acid is added. Using deanstag systam, the medium is heated to 150oC, refluxed for about 2h until no water is collected any more. Ten different types of methyl ethyl ketone formaldehyde resins are synthesized for this study, five of which include nitrogen, one includes boron and three include both nitrogen and boron: methyl ethyl ketone formaldehyde resin (MEKFR), MEKFR modified with alendronic acid at a ratio of 5wt% (MEKFR-AA), MEKFR modified with cyclic urea which is synthesized from alendronic acid at a ratio of 5wt% (MEKFR-CUAA), MEKFR modified with diethanolamine at ratios of 5wt%, 10wt% and 20wt% (MEKFR-DEA), MEKFR and three MEKFR-DEA modified with boric acid (MEKFR-BA and MEKFR-DEA-BA, respectively). After the synthesis and modifications of resins, their chemical structures are analyzed, and Fourier Transform Infrared Spectroscopy (FTIR) and Nuclear Magnetic Resonance Spectroscopy (NMR) are used for this purpose. When the spectums of resins obtained are looked through the characteristics peaks and their corresponding functional groups, it is concluded that the estimated chemical structures as the product of synthesis and modification reactions match with the results obtained. In the terms of physical properties, solubility analyses are carried out in five different solvents, namely ethanol, acetone, dichloromethane (DCM), tetrahydrofuran (THF) and dimethylsulfoxide (DMS), and it is seen that depending on the modifier type and ratio, the solubility of resins change, as a result of the changes in the chemical structures. Lastly, in order to get information about thermal behaviour of the resins and effects of modifications on thermal degradation of them, thermogravimetric analyses (TGA ) and differential scanning calorimetry (DSC) analyses are carried out for each of resins. T50 values and residue amounts of them obtained from TGA curves as well as glass transition and melting temperatures obtained from DSC curves are the crucial parameters used during the evaluation of thermal properties of the resins.
Reaction of acetophenone-formaldehyde resin with s-triazone compounds for fire resistance polyurethane
These days; the use of flame retardants is significantly increasing, especially since plastics are an important part of our daily lives. These materials in general; Bromine, chlorine, metal hydroxide, nitrogen-based, phosphorous-containing or mixtures. The annual consumption of flame retardants is more than 1.5 million in the world market. It costs about $ 2.4 billion. It is seen that the market of flame retardants has increased by 5% per year. The flame retardants could be inorganic or organic. These chemicals can sometimes be used alone as an additive, sometimes in the form of a binary formulation. The important problem here is that these flame retardants must be well dispersed in the polymer matrix. Currently, bromine-based flame retardants are used and their using is limited because side effects are observed. The use of chlorine- and bromine-based flame retardant materials has been restricted or prohibited periodically after 2000 due to the generation of harmful gases and harmful gases to the environment. This has prompted the chemical industry to seek a new generation of flame retardant materials whose distribution is good in polymer, and which is unlikely to produce toxic waste after combustion. The discovery of polyurethane dates back to the year 1937 by Otto Bayer and his coworkers at the laboratories of I.G. Farben in Leverkusen, Germany. The initial works focussed on PU products obtained from aliphatic diisocyanate and diamine forming polyurea, till the interesting properties of PU obtained from an aliphatic diisocyanate and glycol, were realized. Polyisocyanates became commercially available in the year 1952, soon after the commercial scale production of PU was witnessed (after World War II) from toluene diisocyanate (TDI) and polyester polyols. In the years that followed (1952-1954), different polyester-polyisocyanate systems were developed by Bayer. Polyester polyols were gradually replaced by polyether polyols owing to their several advantages such as low cost, ease of handling, and improved hydrolytic stability over the former. Poly(tetramethylene ether) glycol (PTMG), was introduced by DuPont in 1956 by polymerizing tetrahydrofuran, as the first commercially available polyether polyol. Later, in 1957, BASF and Dow Chemical produced polyalkylene glycols. Based on PTMG and 4,4'- diphenylmethane diisocyanate (MDI), and ethylene diamine, a Spandex fibre called Lycra was produced by Dupont. With the decades, PU graduated from flexible PU foams (1960) to rigid PU foams (polyisocyanurate foams-1967) as several blowing agents, polyether polyols, and polymeric isocyanate such as poly methylene diphenyl diisocyanate (PMDI) became available. These PMDI based PU foams showed good thermal resistance and flame retardance. Isocyanates are essential components required for PU synthesis. These are di-or polyfunctional isocyanates containg two or more than two –NCO groups per molecule. These can be aliphatic, cycloaliphatic, polycyclic or aromatic in nature such as TDI, MDI, xylene diisocyanate (XDI), meta-tetramethylxylylene diisocyanate (TMXDI), hydrogenated xylene diisocyanate (HXDI), naphthalene 1,5- diisocyanate (NDI), pphenylene diisocyanate (PPDI), 3,3'-dimethyldiphenyl-4, 4'- diisocyanate (DDDI), 1,6 hexamethylene diisocyanate (HDI), 2,2,4- trimethylhexamethylene diisocyanate (TMDI), isophorone diisocyanate (IPDI), 4,4'- dicyclohexylmethane diisocyanate (H12MDI), norbornane diisocyanate (NDI), 4,4'- dibenzyl diisocyanate (DBDI). Figure 1 shows examples of some common isocyanates. Substances bearing plurality of hydroxyl groups are termed as spolyols. They may also contain ester, ether, amide, acrylic, metal, metalloid and other functionalities, along with hydroxyl groups. Polyester polyols (PEP) consist of ester and hydroxylic groups in one backbone. They are generally prepared by the condensation reaction between glycols, i.e., ethylene glycol, 1,4-butane diol, 1,6-hexane diol and a dicarboxylic acid/anhydride (aliphatic or aromatic). The properties of PU also depend upon the degree of cross-linking as well as molecular weight of the starting PEP. While highly branched PEP result in rigid PU with good heat and chemical resistance, less branched PEP give PU with good flexibility (at low temperature) and low chemical resistance. Similarly, low molecular weight polyols produce rigid PU while high molecular weight long chain polyols yield flexible PU. An excellent example of naturally occurring PEP is Castor oil. Other vegetable oils (VO) by chemical transformations also result in PEP. PEP are susceptible to hydrolysis due to the presence of ester groups, and this also leads to the deterioration of their mechanical properties. This problem can be overcome by the addition of little amount of carbodiimides. In general, reactive flame retardants are composed of halogens and phosphorous. Phosphorus-containing flame retardants may be incorporated into the polymer matrix as an inorganic additive or covalently bonded to the polymer main chain to impart flame retardant properties to the material. In the solid phase, the phosphoruscontaining flame retardant reacts with oxygen in the polymer chain or matrix during heating or combustion. Phosphorus compounds which interact with the polymer form phosphoric acid, and the dimerization of these molecules results in the removal of the water molecules and pyrophosphate formation. Phosphorus based additives as well as phosphorus structures covalently bonded to the polymer chain are both academic and industrial interest. The incorporation of additives into the polymer matrix covalently, or the incorporation and use of monomers in flame retardant structures and polymerisation, is at the forefront of new strategies for "nonflammable polymers." There are hundreds of different flame retardants. They are often broken into categories based on chemical structure and properties. In general, flame retardants are grouped based on whether they contain bromine, chlorine, phosphorus, nitrogen, metals, or boron. Brominated flame retardants — Contain bromine and are the most abundantly used flame retardants. Used in many consumer goods, including electronics, furniture, building materials, etc. and have been linked to endocrine disruption among other effects. Polybrominated diphenyl ethers (PBDE's) PBDEs do not chemically bind with the products to which they are added (furniture, electronics, etc.) so they easily release from these products and enter air and dust. PBDEs can lower birth weight/length of children, and impair neurological development. Tetrabromobisphenol A (TBBPA) Widely used to make computer circuit boards and electronics. Also used in some textiles and paper, or as an additive in other flame retardants. Hexabromocyclododecane (HBCD) An additive primarily used in polystyrene foam building materials. The primary risk to humans is from leaching out of products and getting into indoor dust. Low levels of HBCD have also been found in some food products. Organophosphate flame retardants (OPFRs) With the phasing out of PBDEs, some OPFRs have been identified as replacements. NIEHS-supported researchers are also looking at the health effects of newer flame retardant alternatives that are being brought to market. In this study, condensation product of acetophenone formaldehyde resin (AFR) with alendronic acid s-triazone was produced and modified resins were added 20% , 30% of polyol to the solution at room temperature, used as polyol in the production of rigid polyurethane form in order to improve its fire resistance. AFR was synthesized primarily in basic medium. Then, AFR was modified via their hydroxyl groups by reaction with dimethylol s-triazone that was produced by the reaction of urea with the mixture of formaldehyde and alendronic acid. S-triazone reacts with formaldehyde in the presence of basic catalyst to give dimethylol derivatives. Methylol derivatives of s-triazone give condensation products in an acid media with resin. The mol ratio of s-triazone / resin was about 1/5. Insertion of functional striazone cyclic structure to the AF-Resin effected its physical properties considerably. The products were characterized by FTIR, 1H-NMR, 13C-NMR , 31PNMR, TGA and UL94 analysis. In the combustion tests the foam made from the modified resins self-extinguishes after a certain period of time, while the polyurethane foam obtained from the unmodified resin on the left side continues to burn until completely carbonized. Also, the foams obtained from the modified resins have a rigid structure. Cyclohexanone - formaldehyde resins can be produced in acid and basic media successfully. However, acetophenone – formaldehyde resin can only be produced in basic media in presence of potassium hydroxide. Acetophenone – formaldehyde resin formed in acidic media with very low yield and its softening point was about 20- 250C. The results obtained according to the study are as follows; Acetophenone - formaldehyde resin can be obtained efficiently in the presence of potassium hydroxide in basic medium. Resins can be modified with s-triazone compounds. The materials used in the modification of the resins are readily available and inexpensive materials such as urea and formaldehyde. Depending on the composition of the resin, modification of the resin may change some physical properties such as solubility and flammability. It has been observed that the modified resins have a positive effect on the polyurethane nonflammability such as foam. These results may contribute to the use of resin in the area of incombustibility.