Technical Paper Archive

This site contains all papers presented at Rubber Division, ACS Technical Meetings from 2000-2018. Meetings prior to 2000 are incomplete and papers are added as they are digitized.

For older papers not listed here, please send your request, including Meeting Year, Title, Author, and Paper # to:

View Your Rubber Division Account

Effects of Molecular Architecture and Charge Complexation on Thermoplastic Elastomer Gels

B17 spontak tpe gels

Event: 196th Technical Meeting - Fall 2019
Location: Cleveland, OH
Date: October 08, 2019
Author: Richard Spontak
Paper Number: B17

Price: $20.00

  • Most thermoplastic elastomers (TPEs) based on styrenic block copolymers derive from the triblock architecture, and numerous independent studies have previously demonstrated the unequivocal utility of modulus-tunable thermoplastic elastomer gels (TPEGs) generated from such physical elastomers upon inclusion of a midblock-selective oil. In the present study, we examine two aspects of TPEGs that have received relatively little attention. The first addresses the effect of molecular architecture and employs a TPE series composed of designer multiblock copolymers ranging from triblock to heptablock at constant molecular weight and composition (with styrene and hydrogenated isoprene sequences). The morphological characteristics and mechanical properties of these TPEGs swollen with a rubber-selective aliphatic oil have been analyzed by small-angle X-ray scattering and dynamic rheology as functions of block number and copolymer concentration. Moreover, dissipative particle dynamics (DPD) simulations have been performed to elucidate the dominant network configurations through the introduction of a midblock conformation index. A recognized shortcoming of styrenic TPEGs is their relatively low operating temperature, a consequence of the polystyrene Tg and an order-disorder transition temperature that decreases with decreasing copolymer concentration. Although sulfonation of the endblocks can improve high-temperature performance, it also introduces endblock hydrophilicity that can compromise mechanical properties in a polar environment. We have developed an ionic complexation approach to eliminate water uptake and simultaneously improve the mechanical properties of TPEGs at elevated temperatures. Here, a battery of characterization methods is employed to understand the role of chemical complexation on morphological and property development in both neat TPEs and their gels.

    Papers from 196th Technical Meeting - Fall 2019

    Items from 196th Technical Meeting - Fall 2019