Synthesis And Properties Of Poly(Aryl Ether Ketone)S Copolymers

Poly(aryl ether ketone)s (PAEK) are a type of important high-performance aromatic polymers which are used in automobile, aerospace, medical, and electronic industries. Their excellent mechanical, thermooxidative, electrical and chemical resistance properties make them candidates for advanced materials. Poly(ether ether ketone)(PEEK) is known as an excellent functional material, which is a semicrystalline high-performance thermoplastic with a rigid aromatic backbone structure constituted of a hydroquinone and a benzophenone segment. Nevertheless, it is difficult for most of PAEK to melt and dissolve, which limits their applications in many fields. It is an effective approach to introduce4,4-diphenol, bisphenol A and phenolphthalein into a polymer to afford a polymer containing4,4-diphenol, bisphenol A and phenolphthalein moieties, resulting in the improvement in the solubility and processibility. The copolymers were characterized by infrared spectroscopy (FTIR), wide-angle X-ray diffraction (WAXD), viscosity, solubility, differential scanning calorimeter (DSC), thermal gravimetric analysis (TGA).The main contents of this thesis were as follows:1. From the aspect of different blocking (fluorine blocking or phenolic hydroxyl blocking), different catalyst content (sodium carbonate or potassium carbonate) and different terminate reaction temperature, the synthesis process of PEEK was optimized. The results showed that when n(DFBP)/n(HQ)=l:0.7, n(Na2CO3)/n(K2CO3)=0.95:0.5, and terminate reaction temperature was300℃, the viscosity of polymers was0.89dL/g; when heated at45℃for12h, the polymers were completely soluble in concentrated sulfuric acid and slightly soluble in acetone, while in strongly polar organic aprotogenic solvents such as dimethyl sulfoxide (DMSO), N-methyl-2-pyrrolidone (NMP),N, N'-dimethylformamide (DMF),N, N'-dimethylacetamide (DMAc) and tetrahydrofuran (THF), it can dissolve not at all. The glass transition temperature (Tg) and the melting temperature(Tm) of the polymer were145℃and360℃, respectively, which was the highest temperature and the onset temperature taken weight loss was the highest also. So the polymers exhibited excellent comprehensive property.2. From the aspect of molecular design, we synthesized three new types of poly (aryl ether ketone)s, which were prepared from DFBP,HQ,BP,BPA and Pl by high temperature polycondensation. The results showed that from BP—PAEK, BPA—PAEK to PL—PAEK, all crystallinity of the polymers decreased. When heated at45℃for12h, all the polymers were completely soluble in concentrated sulfuric acid and partly soluble in acetone, while in strongly polar organic aprotogenic solvents such as DMSO,NMP,DMF,DMAc and THF the solubility gradually increases. The glass transition temperature(Tg) of the polymers increased, while the melting temperature(Tm) decreased and the onset temperature taken at10%weight loss of the polymers was all over480℃.3. From the aspect of molecular design, we synthesized one new type of poly (aryl ether ketone)s, which was prepared from DFBP,HQ,BPA and Pl. The results showed that the diffraction peak of polymers was weaker than PEEK,BP—PAEK and BPA—PAEK, while viscosity was less than PEEK,BP—PAEK, more than BPA—PAEK. When heated at45℃for12h, the polymer was soluble in concentrated sulfuric acid and acetone, and in strongly polar organic aprotogenic solvents such as DMSO,NMP,DMF,DMAc and THF, it can basically dissolve. This solubility was more than PEEK, BP—PAEK, but less than BPA—PAEK. The glass transition temperature(Tg) of the polymer was215℃, which higher than PEEK,BPA—PAEK and Pl—PAEK, the same as the onset temperature taken at20%weight loss. And the crystallinity decreases and the melting temperature(Tm) can't be detected.Above studies showed that: firstly, the synthesis of PEEK conditions were optimized, so the comprehensive performances were improved; secondly, starting from the design in molecular strueture, a series of Poly(aryl ether ketone) containing BP,BPA,Pl and BPA—Pl moiety were prepared by us. This new Poly(aryl ether ketone) not only did not reduce thermal resistance, but also had amorphous soluble and melt processability. Therefore, it was very important to investigate the Poly(aryl ether ketone) for their theoretical and practical researches.