Spherical Micelles Based On Functional Poly (Aryl Ether Ketone)s

Poly(aryl ether ketone) (PAEK) has achieved remarkable positions among other thermoplastic polymers because of their unique chemical stability, thermoxidative stability, mechanical properties at high temperatures and radiant resistance.Micelle-like particles formed by polymers have attracted much interest in both theoretical and applied research fields due to their potential applications in catalysis, controlled delivery, artificial cells, light fillers, low dielectric constant materials, acoustic insulation, and photonic crystals. Several approaches have been developed to prepare polymer-based micelle-like particles. Recently, it has been reported that the block and graft copolymers had the ability to form micelle-like particles in a selective solvent, which was a good solvent for one block (or graft) and a non-solvent for the other. Most recently, some new methods, such as changing the pH values of solution, altering the temperature, and chemically modifying one of the blocks or grafts of a copolymer, have been reported to prepare this kind of micelle-like particles. Based on the investigations about the block and graft copolymers, the supramolecules formed by two kinds of polymers via hydrogen-bonding interactions or electrostatic interactions, which are similar to"block copolymers"or"graft copolymers", also have the ability to form micelle-like particles in selective solvents. Compared with most traditional approaches, non-covalently connected micelles method had some advantages, such as more simple preparation conditions and less limitation to materials. Many common polymers, such as poly(4-vinyl pyridine), carboxy-terminated polystyrene and poly(styrene-b-ethylene-co-propylene), have been used to prepare micelles. To our knowledge, poly(arylene ether ketone)s (PAEKs) known as a family of high performance engineering thermoplastics with outstanding physical and chemical properties, have never been used to prepare this kind of stable micelle-like particles.In this study, we focused our attention on the synthesis of a new kind of micelle-like particles based on poly(arylene ether ketone). At first, we designed and synthesized a series of new poly (arylene ether ketone)s containing functional groups, and then the micelles based on these rod-like PAEKs were successfully prepared via hydrogen-bonding interactions. At last, the stable micelle-like particles were abtained by chemical cross-linking. Furthermore, formation conditions, shapes and size of micelles, cross-linking conctions and so no were fully investigated. The main results are summarized as follows:1. A series of PAEKs with hydroxyl terminated (OH-PAEKs) was synthesized. The resulted OH-PAEKs showed good solubility and excellent thermal stability. Two kinds of new bisphenol monomer and a new kind of terminated monomer containing pyridine groups were synthesized, the chemical structure of these new monomers were fully determined by MS,FTIR,NMR and the ultimate analysis. A series of pyridine-substituted poly(aryl ether ketone)s and pyridine-terminated poly(aryl ether ketone) were successfully synthesized from these new monomers. All these polymers exhibited high glass transition temperatures and excellent thermal stability. All polymers demonstrated good solubility, and the PY-PAEKs solubility was better than 2PY-PAEKs, the PY-PAEKs thermal stability was better than 2PY-PAEKs also.2. The micelle-like particles based on OH-PAEKs and PVA via hydrogen-bonding interactions were prepared. The resultant micelle-like particles had two lays structure determined by SEM and TEM, the cores of the micelle-like particles formed by PAEK and the shells of the micelle-like particles fromed by PVA. The factors influenced the size and shap of the micelle-like particles and the mechanism of the formation of the micelle-like particles were fully investigated by means of SEM, TEM, DLS, surface tension instrument and so on. The increasing of the ratio of PVA/PAEK and the decreasing of the concentration of the solution all lead to the smaller micelle-like particles. The supramolecular formed by PAEK and PVA was familiar to the surfactant, the surface tension of the solution desreased obviously. But there was on critical micelle concentration.3. The micelle-like particles based on pyridine-terminated PAEK and PAA via hydrogen-bonding interactions were prepared. The resultant micelle-like particles had two lays structure determined by SEM and TEM, the cores of the micelle-like particles formed by PAEK and the shells of the micelle-like particles fromed by PAA. pH value influenced the formation of the micelle-like particles. When the pH value increased to 4.4, the micelle-like particles could not form. This was associated with the existence of hydrogen-bondings between pyridine groups of PAEK and carboxyl groups of PAA. With the pH value increase, the carboxyl groups transferred to their carboxylate forms and no hydrogen-bondings formed. Increasing of the ratio of PAA/PAEK and the decreasing of the concentration of the solution all lead to the smaller micelle-like particles. The supramolecular formed by PAEK and PVA was familiar to the surfactant, the surface tension of the solution desreased obviously. But there was on critical micelle concentration. In order to prepare the particles having a stable structure, the cross-linked particles were prepared through a reaction between 1,4-dibromobutane and pyridine groups. The size of the cross-linked micelles was obviously decreased after the cross-linking reaction. And the cross-linked system showed well solvent-resistance and pH-resistance.4. The micelle-like particles based on pyridine-substituted PAEK and PAA via hydrogen-bonding interactions were prepared. The resultant micelle-like particles had two lays structure determined by SEM and TEM, the cores of the micelle-like particles formed by PAEK and the shells of the micelle-like particles fromed by PAA. pH value influenced the formation of the micelle-like particles. When the pH value increased to 4.4, the micelle-like particles could not form. This was associated with the existence of hydrogen-bondings between pyridine groups of PAEK and carboxyl groups of PAA. With the pH value increase, the carboxyl groups transferred to their carboxylate forms and no hydrogen-bondings formed. The weight ratio of PAA to PAEK, the concentration of the solution, the content of pyridine groups and the rigidity of the polymer chains all would influenced the formation of the micelle-like particles. The supramolecular formed by PAEK and PVA was familiar to the surfactant, the surface tension of the solution desreased obviously. But there was on critical micelle concentration. In order to prepare the particles having a stable structure, the cross-linked particles were prepared through a reaction between 1,4-dibromobutane and pyridine groups. The size of the cross-linked micelles was obviously decreased after the cross-linking reaction. And the cross-linked system showed well solvent-resistance and pH-resistance.