Study On Synthesis And Structure/Properties Of Alternative Copolymer Aromatic Ether Ketone

1.1,4-Bis(4-Phenoxybenzoyl)benzene was synthesized by nucleophilic and electrophilic substitution: (1)1,4-bis(4-chlorobenzoyl)benzene was obtained from chlorobenzene and terephthaloyl chloride (TPC). Then, the resulting compound p-EKKE was synthesized by 1,4-Bis(4-chlorobenzoyl)benzene with Natrium phenate, taking N-methyl-2-pyrrolidone (NMP) as solvent. (2) p-EKKE was synthesized by Friedel-Crafts acylation of terephthaloyl chloride (TPC) and excessive diphenylether (DPE) in 1,2-dichloroethane with aluminium trichloride (AlCl3) as catalyst. Its structure was characterized by FT-IR, 1H NMR, Micromelting point apparatus, WAXD, SEM and DSC etc. The results show that the compound was anticipated and has high purity. EKKE has the same crystalline diffraction characterization as PEKK which is the unqiue crystallinaion habits of PEKK.2.Poly(Aryl Ether Ketone Ketone)s have excellent thermal stability, resistance to corrosion, creep and other properties, considered as outstanding engineering thermo- plastics. It is very difficult to investigate their micro-structure and properties, for their high melting points and poor solubility in common organic solvents. One of efficient strategies studied the compositions and crystal properties of the macromolecule, attributed to comparing the model compounds which are similar to their segment. In this paper, a series of high molecular weight of alternative and random Poly(Aryl Ether Ketone Ketone) copolymers were prepared by low-temperature solution poly-condensation, with 1,4-Bis(4-Phenoxybenzoyl)benzene (p-EKKE), 1,3-Bis(4- Phenoxybenzoyl)benzene (m-EKKE), diphenyl ether (DPE) and terephthaloyl chloride (TPC) or isophthaloyl chloride (IPC) respectively. The inherent viscosities (ηinh) of resulting copolymers were in the range of 0.63~1.08 dL/g. The chemical structure of p-EKKE, m-EKKE and PEKKs were confirmed by FT-IR. Thermal properties of copolymers obtained by DSC and TG, DSC results indicated that the melt temperature (Tm) and the glass transition temperature (Tg) decreased with increasing of the amount of meso- phenylene substituted in the main chain. TG results show that copolymers had excellent thermo-oxidative stability, and their thermally stable were above 530℃, which affected slightly by the amount of meso- phenylene substituted in the main chain. The alternative copolymer a-PEKK has better order and higher crystallinity than random copolymers. WAXD show that copolymer a-PEKK and the model compound has the same crystallization diffraction spectra, which belong to rhombic system. While the morphology of copolymer i-PEKK and the corresponding model compound attribute to needle crystals, and their type of crystallization belong to anorthic system. i-PEKK is difficult to crystallize again in the course of melting, and it converts into amorphous.3.Poly(aryl ether ketone ketone ether ketone ketone/ether sulfone ether ketone ketone) (PEKKEKK/ESEKK) copolymers of high molecular weight were synthesized by low temperature solution polycondensation of 1,4-bis(4-chlorobenzoyl)-benzene (p-EKKE), 4,4′-diphenoxydiphenylsulfone (DPODPS) and terephthaloyl chloride (TPC) in a catalyst/solvent of AlCl3/ClCH2CH2Cl/DMAc. The copolymers characterized by FT-IR, DSC, TG and WAXD. The results show that copolymers exhibited excellent thermal stability. With increasing the content of DPODPS in the copolymer the glass transition temperature (Tg) of the copolymer improved greatly, while Tm and the degree of crystallinity decreased. When the ratio of DPODPS/p-EKKE is above 70 to 30, copolymers turn into amorphous.4.The alternative polymer a-PEKK which is changed to amorphism by quenching, crystallized by solvant, fusion and elongation at above melting temperature treatment. The crystal morphology of alternative copolymers was examed by DSC and WAXD. The results show that the sample of S3 is crystallized completely treated in dichloroacetic acid about forty-eight hours. Prolonged the time has not been effected to the crystallination. WAXD results showed two crystal types co-exist, but typeⅡdominated in the crystalline. Provided that the thermal treatment of the induced crystallization sample is done at ambient conditions, typeⅡconverted into the most stable crystal typeⅠ. The sample of S4 induced crystallization by fusion in the same temperature only exist crystal typeⅠ. The density of crystalline was affected by the speed of cooling down in DSC. There is no cold crystallization peak in DSC curve by fusion wire drawing orientation treatment. While the sample of S5 processed at fusion temperature for two hours, there is a cold crystallization peak in DSC curve. This strategy indicated that crystal has two types of crystallization. The ratio of crystallinity typeⅠand typeⅡis determined by the the ratio of ketone to ether in the macromolecular chain, wire drawing temperature, the ratio of drawing.