Synthesis And Properties Of Poly(Arylene Ether Nitrile)S Containing Allyl And Phthalazinone Moieties

Poly (arylene ether nitrile)s as a kind of high performance engineering plastics, due to its outstanding mechanical properties, excellent resistance to chemical solvents and heat, are widely used in the fields of military, aerospace and industry. Poly (arylene ether nitrile)s containing phthalazinone (PPENs) destroyed the regularity of the main chain structure to improve their solubility with maintaining their original heat resistance. Allyl group was introduced into the polymer chains as a active group, which can react with thiol, hydro silicon and bismaleimide. Beyond that, allyl group was also a kind of crosslinkable group by UV or heating. In order to make the PPEN functionalization, from the view of designing the molecules, pendent allyl group was introduced into the polymers.A series of crosslinkalbe poly(phthalazinone ether nitrile)s (shorted as DABPA-PPEN) were designed and then prepared by the nucleophilic displacement polycondensation reaction of2,2’-biallyl bisphenol A (DABPA) and4-(4-hydroxylphenyl)-2,3-phthalazine-1-ketone (DHPZ) as bisphenol comonomers and2,6-difluoro benzonitirle. The amounts of pendent allyl groups in the DABPA-PPEN could be easily controlled by adjusting the proportion of DABPA and DHPZ. The structures of the obtained polymers were confirmed by1H-NMR, FI-IR and UV-Vis spectra, respectively. The reaction condition was investigated. The result showed that the isomerization of the allyl group would take place at high reaction temperature to form propenyl group. The optimum of polymerization reaction was catalyzed by KF/CaH2at lower temperature. DABPA-PPEN presented good solubility and could be soluble in some organic polar aprotic solvents. And their solubility slightly slowed down with increasing the ratio of DABPA in the polymer system. Thermal performance tests showed that this kind of PPEN polymers’ Tg and T5%gradually reduce along with the increase of DABPA. DABPA-PPEN-20polymer’s T5%increase nearly20℃after crosslinking reaction of allyl group. The polymers (named as DABP-PPEN) derived from the reaction of DHPZ,2,2’-biallyl biphenol (DABP) and2,6-difluoro benzonitirle showed the same tend as DABPA-PPEN. Moreover, more than40℃of T5%in DABP-PPEN system after curing was observed. DABP-PPEN displayed the more stable thermal properties than the analogue DABPA-PPEN.