Study On Synthesis And Properties Of Low-Cost Poly (Phthalazinone Ether Ketone)s

Poly(aryl ether ketone)s (PAEKs) are an important category of high-performance materials for their excellent thermal and mechanical properties, which have been used in aerospace, electronics, separation film and adhesive etc. Poly(phthalazinone ether ketone)s, a type of novel PAEK materials, have been developed in our group in the last decade. Compared with traditional poly(aryl ether ketone)s, this kind of materials is possessed of better thermal properties with improved solubility, which not only facilitates the synthetic conditions but also improves the solution processibility. From a raw materials cost point view, however,4,4’-difluorobenzophenone (DFK) is used as traditional industry, which results in high cost.In this thesis, poly(phthalazinone ether ketone) (PPEK) and its copolymers of PPESKs, PPENKs, PPBESKs and blockcopolymer PPESK-b-PEBEK containing biphenyl groups were synthesized from 4-(4-hydroxyphenyl)(2H)-phthlazin-l-one (DHPZ) and 4,4’-dichlorobenzo phenone (DCK). And the polymerization conditions and relationships between properties and structures of the polymers were also elaborated in details.First, considering the structure character of DHPZ,2-phenyl-4-(hydroxylphenyl)(2H)-phthalazin-1-one (PHPZ) and 4-(4-methlyphenyl)(2H)-phthalazin-l-one (MHPZ) were synthesized. The products of the reactions of MHPZ and DCK, PHPZ and DCK indicated that it was feasible for the reaction of DHPZ and DCK. High performance liquid chromatogram (HPLC) was used to monitor the reaction of MHPZ, PHPZ and DCK, which implied that the reactivity of-OH and-NH was different, and the conversation of-NH was lower.The influence of polymerzaition conditions of DCK and DHPZ, including the solvents, temperature, reaction time etc. on the product was investigated. When sulfolane was chosen as the solvent, high molecular weight polymer could be obtained in 7-8h at 210℃. Moreover, the molecular weight was controlled and molecular weight could increase with the addition of a third comonomer. When the excessive DCK was 0-1.6% and the excessive DHPZ was 0-2%, the intrinsic viscosities of the polymer could be controlled between 0.67-0.26dL/g and 0.67-0.32dL/g, respectively. And the thermal and mechanical properties of the obtained polymer were identified with those of PPEK synthesized from DHPZ and DFK. By a two-step procedure with addition of a little DFK, the intrinsic viscosity of the polymer could be up to 1.10dL/g. On the basis of statements above, the comonomer such as 4,4’-dichloro diphenyl sulfone (DCS),2,6-dichlorobenzonitrile (DCBN) and 4,4’-biphenol (BP) had been used to synthesize copoly(phthalazinone ether ketone)s. These series of copolymer of PPESKs, PPENKs and PPEBSKs were successfully prepared. The copolymers were possessed with high glass transition and excellent thermal stability. T5%s were above 500℃. Tough, flexible and transparent thin film can be readily prepared from their N-methyl-2-pyrrolidone solution. And the films exhibited good mechanical properties. The melt viscosity of PPBESKs was effectively decreased by the introduction of the biphenyl groups according to the HAAKE tests. And the more biphenyl groups led to lower melt viscosity.Block polymer of PPESK-b-PEBEK containing phthalzinone and biphenyl groups was successfully synthesized from DHPZ, DCK, DCS BP and DFK. The biphenyl groups were introduced to the polymer’s main chain indicated by FT-IR and 1H-NMR. The block copolymer could be soluble in CHCl3, N-methyl-pyrollidione (NMP) etc. at room temperature. The block polymer was possessed with excellent thermal properties, T5% was 510℃. The glass transition temperature of PPESK-b-PEBEK was 243℃, and the melting temperature was 327℃, which indicated the crystalline segments. And the PEBEK crystalline segments also could be evidenced by the peaks at 2θ=18.8°,23.5°on the WAXD curve and the white and opaque film of the polymer’s NMP solution. Compared with pure PPESK, the melt viscosity of PPESK-b-PEBEK was increased according to the HAAKE tests. The blockcoplymer could be easily extruded at about 340℃, and the extrusion sample was translucent brown, smooth and tough.