Optimizing Processing and Formulation Strategies for Enhanced Thermal and Chemical Stability of Meltblown Polyphenylene Sulfide Nonwovens

ABSTRACT Polyphenylene sulfide (PPS) meltblown nonwovens are attractive for high‐performance filtration and protective applications owing to their intrinsic chemical resistance, thermal stability, and flame retardancy. However, their long‐term dimensional stability and resistance to thermal aging remain critical limitations for deployment in harsh environments. Granulation pretreatment enabled the release of sulfur‐containing volatiles through interparticle gaps during extrusion, thereby preventing melt flow disruption and ensuring continuous fiber formation without altering the intrinsic degradation onset of PPS. Incorporation of 3 wt% polyetherimide (PEI) markedly suppressed thermal shrinkage during isothermal aging up to 180°C, reducing pore size contraction to below 10% compared with ~30% in pristine PPS. Thermogravimetric analysis (TGA) confirmed that incorporation of PEI did not lower the degradation temperature of PPS, indicating that stabilization arose from intermolecular interactions and interfacial compatibility between PPS and PEI. Both pristine PPS and PPS + PEI nonwovens retained excellent chemical resistance against strong acids, concentrated alkali, and organic solvents, with negligible weight loss even under elevated‐temperature alkaline exposure. High limiting oxygen index (LOI) further confirmed their inherent flame retardancy. Most importantly, the loft and compactness of PPS meltblown webs, previously described as uncontrollable and inherently loose, were successfully tuned by adjusting the die‐to‐collector distance (DCD), polymer throughput, and collector design.