The Synthesis, Cross-linking Solidification And Their Properties Of Novel Hyperbranched Poly (Ether Ketone)

Hyperbranched polymers are a relatively new class of macromolecules which have a unique globose molecular structure.Compared with the traditional linear polymers, hyperbranched polymers have large numbers of branched units,and possess many characteristics such as low viscosity of both fused mass and solution,abundant terminal functional group,no chain entanglement,non-crystallize,etc.Hyperbranched polymers could be applied widely in high-performance coating,molecular initiator,rheology additives, opto-electrical materials,etc.Hyperbranched poly(ether ketone) is an important element in hyperbranched polymers,and it is highly concerned for it is hopeful to solve the classical linear poly(ether ketone)'s weak point of poor solubility or working quality.A kind of new AB₂ aromatic monomer,2-(4-flurobenzoyl)-1.4-hydroquinone(FBHQ), was synthesized through Friedel-Krafts acrylation,in which 4-flurobenzoyl chloride and hydroquinone were used as raw materials,and the product was also characterized.The synthetic route was also studied through orthogonal experiment systemically by discussing the mole ratio of the materials,the amount of catalyst,reaction temperature and the amount of solvent in this paper.The yield of the resultant product was 61.3%.Then a series of new hyperbranched poly(ether ketone)s(HBPEKs) were synthesized through self-condensation polymerization by FBHQ as material,and reactive nucleus were introduced into the system. HBPEKs were characterized and the properties were also tested.¹H-NMR measurement indicated that the degree of branch(DB) of HB-PEKs is 0.25.After introducing nucleus, HBPEKs are well soluble in several organic solvents such as NMP,DMAc,sulfolane,DMSO and DMF,etc,the Tg of HBPEKs ranged from 147 to 227℃,and 5%weight loss temperature ranged from 348 to 420℃.In addition,two kinds of hyperbranched poly(ether ketone)s with different terminals were synthesized through co-condensation polymerization by di-fluro ketone ketone(DFKK) and phloroglucinol as materials.Effect of factors including mole ratio of materials,reaction time and reaction temperature on the viscosity of HBPEKs were studied,and the structures and properties of two series of HBPEKs were characterized and tested respectively.¹H-NMR measurement indicated that the degree of branch(DB) of hydroxyl-and fluoro-terminated hyperbranched poly(ether ketone)s were 0.64 and 0.60 respectively.These two kinds of HBPEKs were both well soluble in several organic solvents such as NMP,DMF,DMAc, DMSO,THF,CHCl₃,etc.And the Tg of OH-HBPEK and F-HBPEK were 221 and 138℃, the 5%weight loss temperatures were 435 and 457℃,respectively.In order to improve the polymers' mechanical property,the terminal groups of the hydroxyl-terminated hyperbranched poly(ether ketone)s were partly modificated by end-capping with unsaturated groups.Then modificated HBPEKs were cross-linked to be paint film through thermal initiation in which BPO was used as initiator,and the hardness, mechanical properties and corrosion-resistant properties of the paint films were studied.Effects of cross-linking density,solidifying temperature and solidity time on the property of the paint films were also studied.The paint films after solidification were insoluble in any solvent,and 5%weight loss temperature was higher than HBPEKs before modification for 84℃,and the carbon residue at 800℃was also higher for about 15 percentages.