Study On Synthesis And Properties Of Poly Aromatic Ether Ketone Containing Multi-ketonic Linkage And Monomer

With the development of high-tech, the need for high-performance polymers grows day by day, and higher demand for their integrative property, especially the thermostability have been advanced. As for poly(aryl ether ketone)s(PEKs), the ketonic linkage and the ether linkage are contained, and the rigidity of the ketonic linkage is stronger than the ether linkage's, so the increasing ratio of the ketonic linkage in the macromolecule chain can make the polymers exhibit more excellent thermostability. In this paper, above all, two monomers have been successfully synthesised. Then PEKs based on them have been synthesised and characterized. Last, the relation between the structure and properties of the polymers have been studied. The main idea of this paper is followed.1. 1,3-Di(4-methyl benzoyl)benzene(i-DMBB) was prepared by Friedel-Crafts electrophilic aromatic substitution reaction from isophthaloyl chloride (IPC) and toluene; i-DMBB was subsequently oxidated into intermediate, 1,3-di(4-carboxyl benzoyl)benzene(i-DMBA) in the presence of KMnO4 in the mixture solvent of pyridine and water; then the reaction of i-DMBA with sulfurous oxychloride yielded polymerization-grade monomer 1,3-di(4-chloro formyl benzoyl)benzene(i-DMBC). 1,4-di(4-chloro formylbenzoyl)benzene(p-DMBC) was obtained on condition that the reaction started with terephthaloyl chloride (TPC) and toluene. The products were characterized by FT-IR, 1H-NMR, elemental analysis and DSC. It was proved that high purified compounds had been obtained, and they can become monomers and remodeling reagents of high-performance polymers, such as poly(aryl ether ketone)(PEK), polyarylates(PAR) and aryl polyamide.2. Novel poly(aryl ether ketone)s(PEKs) containing multi-ketonic linkage were prepared by low temperature solution polycondensation of i/p-DMBC with 4,4'-diphenoxydiphenylsolfone(DPODPS), 1,3-di(4-phenoxybenzoylbenzene (i-DPOPKK) and 1,4-di(4-phenoxybenzoyl)benzene(p-DPOPKK) in 1,2-dichloro -ethane(DCE) with the presence of AlCl3 and DMAc. The resulting polymers were characterized by various analytical techniques, such as FT-IR, 1H-NMR, DSC, TGA and WAXD. The relation between the structure and properties of the polymers had been studied. The results show that high molecular weight polymers have been readily obtained. With the increasing ratio of ketonic linkage in the macromolecule chain, the polymers exhibit excellent thermostability, such as the highest glass transition temperature(Tg) of the polymers is 189℃, the highest melting temperature(Tm) of the polymers is 403℃. At the same time, the introducing of the tetrahedral sulfonyl(-SO2-) and meta-phenyl substitution can make the Tm of the polymers decrease appropriately, and the solubility of the polymers is also improved. Furthermore, with the increasing ratio of ketonic linkage in the macromolecule chain, the structure of the polymers has changed , polymorphism is easily to be found. We have found two crystal types, FormⅠand FormⅡ, in the polymers via the analysis of WAXD and DSC.3. The crystallization of poly(aryl ether ketone) containing multi-ketonic linkage, PEKKEKK-i-KK, was studied by differential scanning calorimetry(DSC) and wide-angle X-ray diffraction(WAXD). The relation between the structure and properties of the polymers has been studied in further from the microcosmic angle, and the evidence of processing and properities has been provided. The results show that there are two crystal types, FormⅠand FormⅡ, in the polymers, and the crystal type of FormⅠis more stable than the crystal type of FormⅡ. The ratio of FormⅠand FormⅡcan be changed by way of different treatment, such as induced crystallization of thermal treatment, elongation and so on. Moreover, the polymer, which just contains the crystal type of FormⅠ, can be obtained via elongation.