Синтез, властивості та застосування амфіфільних олігомерів на основі піромелітової кислоти

Abstract

В дисертації розроблені наукові та практичні основи синтезу нових амфіфільних олігомерів на основі піромелітової кислоти та поліетиленгліколів, з ліпофільними фрагментами вищих аліфатичних спиртів або холестеролу, а також амфіфільних олігопероксидів з різною природою пероксидних груп, в тому числі структури «gemini». Досліджено колоїдно-хімічні властивості синтезованих олігомерів. Утворювані ними міцелярні структури здатні солюбілізувати такі ліпофільні речовини, як водонерозчинні барвники, ефірні олії, риб’ячий жир, холестерол, куркумін. Олігопероксиди можуть слугувати ефективними емульгаторами полістиренових емульсій і дають можливість одержувати монодисперсні латекси, частинки яких містять на поверхні залишкові реакційноздатні пероксидні групи. Розроблено метод одержання самоогранізованих субмікронних частинок через інтерполімерну електростатичну взаємодію між протилежно зарядженими макроланцюгами хітозану та олігопероксиду. Показана можливість пероксидації олігопероксидами поверхні крохмалевих зерен, волокон регенерованої целюлози, карбонових нанотрубок, поліетилентерефталату. В диссертации разработаны научные и практические основы синтеза новых амфифильных олигомеров на основе пиромеллитовой кислоты и полиэтиленгликолей, с липофильными фрагментами высших алифатических спиртов или холестерина, а также амфифильных олигопероксидив с разной природой пероксидных групп, в том числе структуры «gemini». Исследованы коллоидно-химические свойства синтезированных олигомеров. Образуемые ими мицеллярные структуры способны солюбилизировать такие липофильные вещества, как водонерастворимые красители, эфирные масла, рыбий жир, холестерин, куркумин. Олигопероксиды могут служить эффективными эмульгаторами полистирольных эмульсий и дают возможность получать монодисперсные латексы, частицы которых содержат на поверхности остаточные реакционноспособные пероксидные группы. Разработан метод получения самоогранизованных субмикронных частиц путем интерполимерного электростатического взаимодействия противоположно заряженных макроцепей хитозана и олигопероксида. Показана возможность пероксидации олигопероксидами поверхности крахмальных зерен, волокон регенерированной целлюлозы, карбоновых нанотрубок, полиэтилентерефталата. The scientific and practical bases for the synthesis of new amphiphilic oligomers on the basis of pyromellitic acid and polyethylene glycols, with lipophilic fragments of higher aliphatic alcohols as well as cholesterol have been developed. Some of them possess structure of “gemini” type. Synthesis is carried out through acylation by pyromellitic dianhydride of hydroxyl-containing nucleophiles of hydrophilic and lipophilic nature. In this case, one of the nucleophiles is a mono methyl of polyethylene glycol and has a hydrophilic nature, and the other one – an aliphatic alcohol of normal structure or cholesterol and has lipophilic properties. The hydrophilic-lipophilic balance of the resulting oligomers can be controlled by the length of the polyethylene glycol oxyethylene chain and the nature of the lipophilic moiety. The resulting oligomers are pyromelic acid disesters. Their structure is confirmed by functional analysis, IR, PMR spectroscopy and mass spectrometry. The methods for the synthesis of new surface-active oligomers with peroxide functional groups of different types, based on pyromellitic tetra acyl chloride and polyethylene glycols have been described. Depending on the nature of the peroxide groups, oligomers are capable of forming free radicals at a temperature range of 50 to 150 °C, while the length of the hydrophilic oxyethylene chain determines solubility in water, organic solvents, as well as hydrophilic-hydrophobic balance, surface-active and solubilizing properties of oligomers. Oligomers contain carboxylic or acyl chloride functional groups. The new amino peroxides, containing hydroxyl groups have been prepared by the condensation of monoethanolamine with tert-butylperoxymethanol. On their basis new oligoperoxids with amino-peroxide fragments have been created. A new surface-active oligoperoxids of "gemini" type with peroxide and carboxyl groups were synthesized. A method of obtaining a peroxiester with a reactive anhydride group is developed by the interaction of pyromellitic dianhydride with tert-butyl hydroperoxide. For this purpose, the kinetic regularities of the reaction of pyromellitic dianhydride with tert-butylhydroperoxide have been investigated. A mathematical model of the process was created on the basis of kinetic studies and the conditions to promote the maximum yield of the peroxiester with anhydride group are determined. Such peroxiester can be used for introduction of peroxide fragments into various compounds through the acylation reaction. The colloidal and chemical properties of synthesized oligomers were investigated. The surface activity of diesters depends on the pH values due to presence of two carboxyl groups in the pyromellitic acid fragment. At concentrations in water lower than CCM, the oligomers form a dispersed phase with a particle size of 2-10 nm. Upon reaching the CCM, the formation of micelles with a rather narrow distribution in sizes and with an average diameter of 40-100 nm, begins. While increasing concentrations, the geometric dimensions of the micelle are gradually increased to 60-250 nm. It has been established that both micelles and micellar aggregates have a negative ζ-potential in the range -10 ÷ -60 mV due to the presence of ionized carboxyl groups on their surface. Presence of negative ζ-potentials is a very important factor when using oligomers as nano-sized drugs cariers. The formed micellar structures are capable of solubilizing such lipophilic substances as water-insoluble dyes, essential oils, fish oil, cholesterol. Solubilizing the water-insoluble anticancer drug curcumin, they not only provide its stability for a long time, but also release curcumin into 1-octanol, which can be used as a model of the layer of phospholipids in the cell membrane. These facts consider oligomers to be appropriate materials for constructing target drug delivery systems. Synthetic oligoperoxids are also shown to be typical amphiphilic substances. They can serve as effective emulsifiers of polystyrene emulsions and make it possible to obtain mono-dispersed latexes, whose particles contain residual reactive peroxide groups on the surface. A method for the preparation of self-organized reactive submicron particles based on chitosan and peroxide oligomer was developed. The size of the particles depends on the pH of the medium and the ratio of chitosan and oligomer. The particles demonstrate? pH-sensitive properties and are able to change the size or solubility in response to changes of pH. The presence of peroxide groups in the particles makes it possible to form covalently crosslinked network and lose the ability to dissolve. Both uncured and covalently crosslinked particles can be used to create polymeric drug transport systems. The possibility of modifying starch by peroxide oligomers with acyl chloride groups was shown. In the process of modification, peroxide groups are saved and can be used as radical-formating centers for grafting polymer chains. Such starches with adhered to the surface polymer layer can be used as an effective fillers for polymere composites. The method of modification of regenerated cellulose fibers by peroxide oligomers with carboxyl groups is developed. Such peroxidated fibers are of interest for the production of composites based on polyolefins, in particular polypropylene. Due to presence of peroxide groups on their surfaces modified fibers are able to form strong interphase bonds in these composites by grafting the polymer matrix to the fiber surface. “Gemini” oligoperoxides can be used to modify the surface of NH2-functionalized carbon nanotubes. Modified nanotubes are easily dispersed in the polymer matrix and allow to improve the mechanical properties of nanocomposites based on polybutylene terephthalate - polytetra methylene oxide compared to unmodified nanotubes. It is shown that synthesized oligoperoxids can be attached onto polyethylene terephthalate surface to form bonded nanolyers. The following polymeric layers, in particular polysaccharide, could be attached due to decomposition of peroxide groups and reaction of radical chain transfer to polysaccharide. Surfaces with covalently attached polysaccharide nanolayer are an important implement for biochemical studies. The variation of free surface energy values as well as its components in the process of modification of polyethylene terephthalate with oligoperoxides and dextran has been studied.