SYNTHESIS OF NOVEL POLY(PHTHALAZINONE ETHER SULFONE KETONE)S AND IMPROVEMENT OF THEIR MELT FLOW PROPERTIES

A series of novel poly(phthalazinone ether sulfone ketone)s was synthe sized from bis(4-fluorophenyl) ketone, bis(4-chlorophenyl) sulfone, an d 4-(4-hydroxybenzyl)-2,3-phthalazin-1-one through nucleophilic substi tution polycondensation. The synthesized polymers exhibited surprising ly high glass transition temperatures and had excellent thermooxidativ e properties. The melt viscosities of these synthesized polymers are g enerally too high to be processed by common processing methods because of their very high glass transition temperatures and amorphous micros tructure. An attempt was made to reduce their melt viscosities by solu tion blending the synthesized polymer with two kinds of oligomers: low molecular weight poly(phthalazinone ether sulfone ketone) and commerc ial poly(ether sulfone). The results proved that the addition of the o ligomers to the polymers led to a marked decrease in melt viscosities. Furthermore, no obvious changes were observed in the thermal and mech anical properties of these blends after oligomer additions. (C) 1997 J ohn Wiley & Sons, Inc.