New Evaluation Methods of Average Molecular Weight and the Degree of Branching of Poly(1,4-phenylene sulfide) Samples through Their Partial Sulfonation

• Published in: Fibers and polymers 2022, 23(4), , pp.900-913
• Main Authors: Pervin, Shamim-Ara, Prabu, Arun Anand, Kim, Kap Jin
• Format: Article
• Language: English
• Subjects: Ambient temperature; Chemistry; Chemistry and Materials Science; Curve fitting; Dichloromethane; NMR; Nuclear magnetic resonance; Polymer Sciences; Polymerization; Solvents; Structural analysis; Viscometers; Viscosity measurement; 섬유공학
• ISSN: 1229-9197; 1875-0052
• DOI: 10.1007/s12221-022-4663-5

Structural characterization of industrial-grade poly(1,4-phenylene sulfide) (PPS) batch samples (solution- and melt-polymerized) can only be carried out using expensive and least available solid-state NMR/high-thermal viscometer due to their insolubility in common organic solvents even at 200 °C. In the present study, we prepared sulfonated PPS (sPPS) which is soluble in common organic solvents even at ambient temperature conditions, thereby facilitating its easier characterization in the solution state at R.T. using FTIR, NMR, and solution-viscosity measurements. sPPS was synthesized through the anionic modification of PPS using chlorosulfonic acid (ClSO 3 H) and dichloromethane as a function of varying PPS:ClSO 3 H mole ratio (1:5 and 1:10) and sulfonation time (1 to 48 h). A previously unreported methodology to identify the branching types (phenylene and sulfide branching) in PPS was carried out using 1 H-NMR curve-fitting analysis with Lorentzian equation. Melt-polymerized PPS samples were analyzed to contain about two times higher degree of branching than the solution-polymerized PPS ones.