Synthesis and thermal properties of poly(phenylene sulfide-co-phenylene sulfide ketone)

Poly(phenylene sulfide-co-phenylene sulfide ketone)s (PPS/SK) were synthesized from p-dichlorobenzene (DCB)/4,4'-dichlorobenzophenone (DCBP) and p-dibromobenzene (DBB) /DCBP monomer pairs using sodium sulfide trihydrate (Na2S . 3H(2)O) in N-methyl-2-pyrrolidinone (NMP) solvent. The yield and molecular weight of the PPS/SK copolymers were higher with the DBB/DCBP/Na2S monomers. The copolymer composition and molecular weight of the PPS/SK copolymers were determined by an elemental (C, H, S) analysis and high temperature (210 degrees C) GPC with 1-chloronaphthalene as an eluent, respectively. The molecular weight of the PPS/SK copolymers showed a maximum value at a feed ratio of [DBB]/[DCBP] = 70/30 mol%. The plot of the Tg'S Of the PPS/SK copolymers relative to the copolymer content of the DCBP repeat unit matched well with Fox equation. As the content of the DCBP unit increased in the PPS/SK copolymers, the T-g of the PPS/SK copolymer also increased. The PPS/SK copolymers exhibited T-m's with all compositions at a 20 degrees C/min scan rate for the DSC measurement. The eutectic point appeared to be 267.2 degrees C with 29.8 mol% DCBP units in the copolymers.