Synthesis and characterization of poly(p-arylene sulfide ketone/Schiff base) copolymers

Abstract

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.

Synthesis and Characterization of New Photoresponsive, Ortho and Para Oriented Azomethine Polymers

“…26 To improve their solubility different arrangements are made in their structure, which includes ether and ester linkages, introducing solution enhancing groups 27 copolymerization and blending. [28][29][30] Flexible spacers have also been introduced to enhance their solubility without affecting their thermal stability. 31 In the present work five new photo-responsive polyazomethines were synthesized, they differ in orientation of ether groups attached with the aromatic rings and also various types of aromatic or alicyclic rings were incorporated in the polymer chain, the purpose of these structural modifications was to investigate their effects on the properties (solubility, thermal stability and fluorescence) of polymers.…”

Influence of Water Regulation on Internal Heavy Metal Load for a Tide-Influenced Waterfront Lake

“…The rotation speed of the oscillator was set as 90 r•min -1 , 120 r•min -1 , 150 r•min -1 , 180 r•min -1 and 220 r•min -1 , and the amounts of dissolved and suspended Pb in the samples under different disturbance intensities were measured. Pb release rates were calculated by equation ( 1) [11][12]:…”