435106 Shear Alignment of Thermoplastic Elastomers Utilizing Large Amplitude Oscillatory Shear

Tuesday, November 10, 2015: 2:00 PM
251B (Salt Palace Convention Center)
Shu Wang1, Sameer Vajjala Kesava2, Enrique D. Gomez2 and Megan L. Robertson1, (1)Department of Chemical and Biomolecular Engineering, University of Houston, Houston, TX, (2)Chemical Engineering, Pennsylvania State University, University Park, PA

Linear ABA triblock copolymers find widespread utilization as thermoplastic elastomers (TPEs): materials which exhibit elastomeric behavior at room temperature and can be readily processed at elevated temperatures. Traditional TPEs are derived from fossil fuels; however, the finite availability of petroleum and the environmental impact of petroleum processing has led to an increased interest in developing alternative sources for polymers. Vegetable oils and their fatty acids are promising replacements for petroleum sources due to their abundance, low cost, lack of toxicity, biodegradability and ease of functionalization that provides convenient routes to polymerization. In this study, triblock copolymer TPEs were synthesized containing lauryl and stearyl acrylate, derived from fatty acids found in vegetable oils. Small-angle X-ray scattering experiments revealed highly aligned triblock copolymer morphologies after the application of large amplitude oscillatory shear. The temperature and frequency dependence of the degree of alignment was investigated. In contrast to prior studies on shear-aligned morphologies in bulk and thin film block copolymers, hexagonal close packed and face centered cubic spherical structures were observed.

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See more of this Session: Nanoscale Structure in Polymers
See more of this Group/Topical: Materials Engineering and Sciences Division