Poly(p-arylene sulfide ketone/Schiff base) copolymers (PASK/SB) were prepared by solution polycondensation of 4,4′-diflurobenzophenone (DFBP) and N-phenyl(4,4′-diflurodiphenyl) ketimine (DFBI) with sodium sulfide in the presence of sodium hydroxide under normal pressure. Elemental analyses, FT-IR, NMR, DSC, TGA and XRD were used to characterize the resultant copolymers. It was found that the copolymers had good thermal properties with glass transition temperature (T g ) of 155.0−172.0°C, melting temperature (T m ) of 298−344°C, 5% weight loss temperatures (T d ) of 471.0−501.5°C. These copolymers were almost amorphous with the content of DFBI beyond 30%. The polymer with 100% DFBI had excellent solubility, and it could dissolve in some solvents such as tetrahydrofuran (THF) and N-methyl-2-pyrrolidone (NMP). The processability of polymers was improved. Meantime the viscosity of PASK made from hydrolysis of PASK/SB (H-PASK/SB) was greatly improved from 0.135 dL/g to 0.605 dL/g.
The molecule of the title compound, C25H20N2OS2, has imposed twofold rotation symmetry. The dihedral angle formed by the two crystallographically independent phenyl rings is 79.23 (7)°. In the crystal packing, the molecules are linked by intermolecular N—H⋯O hydrogen bonds, forming chains running parallel to [102].
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.