POSS‐induced rheological and dielectric modification of polyethersulfone. Issue 23 (8th February 2021)

• Record Type: Journal Article
• Authors: Shankar, Rahul; Kemp, Lisa K.; Smith, Nicholas A.; Cross, Jacob A.; Chen, Beibei; Nazarenko, Sergei I.; Park, Jin Gyu; Thornell, Travis L.; Newman, John K.; Morgan, Sarah E.
• Is Part Of: Journal of applied polymer science. Volume 138:Issue 23(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-02-08
• Subjects: dielectric properties -- microscopy -- morphology -- rheology -- viscosity and viscoelasticity; Polymers -- Periodicals; Polymerization -- Periodicals; 668.9
• DOI: 10.1002/app.50537
• Languages: English
• ISSNs: 0021-8995

Abstract

Abstract: Polyhedral oligomeric silsesquioxane (POSS) nanostructured chemicals, when incorporated at low levels in thermoplastics, provide processability enhancement and viscosity reduction without compromising other bulk physical properties. POSS has been relatively unexplored in high performance polymers, and there is incomplete understanding of the mechanisms by which POSS produces flow improvements. In this study, polyethersulfone (PES) was melt‐blended with trisilanolphenyl (TSP)‐POSS and dodecaphenyl (DP)‐POSS; and rheological, dielectric spectroscopy, and scanning electron microscopy evaluations were conducted to identify structure/property/processing relationships. TSP‐POSS yielded greater processability improvements and viscosity reductions than DP‐POSS, suppressed low temperature relaxations to a larger extent, and displayed a greater degree of nanoscale dispersion in the polymer matrix. The findings are evaluated in terms of competing theories of POSS viscosity reduction. Abstract : POSS nanostructured chemicals provide flow enhancement when added at low concentrations to polyethersulfone melt blends, while thermal and mechanical properties remain unchanged. Dielectric spectroscopy, rheology, and morphology evaluations indicate that the effect is the result of reduction in chain entanglements and increase in matrix free volume. The observed processing improvement has potential application in reducing energy expenditure in the manufacture of high‐performance thermoplastic composites.