Aromatic polymers obtained by precipitation polycondensation: 4. Synthesis of poly(ether ketone ketone)s☆
Abstract High molecular weight aromatic poly(ether ketone ketone)s were synthesized by the Friedel-Crafts polyacylation condensation of iso- and terephthaloyl chlorides with diphenyl ether, 1,4- and 1,3-bis(4-phenoxybenzoyl)benzenes. Depending on the monomers used for polycondensation, polyketones of regular structure with different iso-/tereisomer repeating unit ratio ( 100 0 , 50 50 , 0 100 ) in the main chain were obtained. Polymers of each repeating isomer unit were prepared in two different ways. All the polymer syntheses were performed as precipitation polycondensations and the resulting polymers were obtained in particle form. The influence of reaction conditions and preparation route on the polymer properties were examined. The monomer concentration and monomer stoichiometric ratio were found to affect the polymer viscosity. The size and shape of the polyketone particles obtained were also found to be governed by reaction conditions and preparation route.
Synthesis and characterization of novel poly(aryl ether ketone)s containing both biphenylene and 1,4-naphthylene moieties
A monomer containing naphthalene, 4,4′-di(1-naphthoxy)benzophenone (DNOBN), was easily prepared by the condensation reaction of 4,4′-difluorobenzophenone with 1-naphthol. Novel poly(aryl ether ketone)s containing both biphenylene and 1,4-naphthylene moieties were synthesized by the electrophilic Friedel-Crafts acylation copolycondensation of isophthaloyl chloride (IPC) with a mixture of 4,4′-bis(4-phenoxybenzoyl)diphenyl (BPOBDP) and DNOBN, over a wide range of BPOBDP/ DNOBN molar ratios, in the presence of anhydrous AlCl3 and N-methylpyrrolidone (NMP) in 1,2-dichloroethane (DCE). The copolymers with 10–30 mol% DNOBN are semicrystalline and had much higher Tgs than those of the conventional PEEK and PEKK due to the incorporation of both biphenylene and 1,4-naphthylene moieties in the main chain. The copolymers IV and V with 25–30 mol% DNOBN showed high Tgs of 182–183 °C and moderate Tms of 336–338 °C with good potential for melt processing. The copolymers IV and V had tensile strengths of 101.2–102.5 MPa, Young’s moduli of 2.81–2.93 GPa, and elongations at break of 19.8–20.6 % and exhibited high thermal stability and excellent resistance to organic solvents.
Self-assembly of pyridinium-tailored anthracene amphiphiles into supramolecular hydrogels.
The mixing of a polyacid cross-linker with a pyridinium-functionalized anthracene amphiphile afforded a supramolecular hydrogel through a self-assembly process that was primarily driven by π-stacking and electrostatic interactions.