Enhanced miscibility and strain resistance of blended elastomer/π‐conjugated polymer composites through side chain functionalization towards stretchable electronics

• Published in: Polymer international Vol. 69; no. 3; pp. 308 - 316
• Main Authors: Pakhnyuk, Viktoria, Onorato, Jonathan W, Steiner, Emily J, Cohen, Theodore A, Luscombe, Christine K
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01.03.2020; Wiley Subscription Services, Inc
• Subjects: Chains (polymeric); conjugated polymer; Crosslinking; Deformation resistance; elastomer; Elastomers; Interfaces; Miscibility; Morphology; Organic chemistry; Polybutadiene; Polymer blends; Polymer matrix composites; Polymers; Strain; stretchable electronics; Transistors
• ISSN: 0959-8103; 1097-0126
• DOI: 10.1002/pi.5954

This work presents improved compatibility in an elastomer/π‐conjugated polymer blend through side chain functionalization of the electronic polymer. Poly[(3‐(6‐bromohexyl)thiophene)‐ran‐(3‐hexylthiophene)] (P3BrxHT, x = 0%–100%) was synthesized (i) to improve miscibility with polybutadiene (PB) elastomer through altered π–π interactions and (ii) to covalently bond across phase‐segregated interfaces. Functionalization led to morphology with reduced domain sizes to improve crack onset strain from 7% to 40%. Furthermore, UV‐activated crosslinking reinforced mechanically weak interfaces and yielded at least an additional 40% increase in crack onset strain. Charge mobility in PB/P3BrxHT organic field‐effect transistors showed minimal dependence on bromide concentration and no negative effects from crosslinking. Functionalization was an effective method to reduce brittleness in PB/P3BrxHT blends through morphology modification and crosslinking to improve stability towards strain for potential stretchable electronic applications. © 2019 Society of Chemical Industry Bromide functionalization of the π‐conjugated polymer lead to improved compatibility with the elastomer via reduced domain sizes and interfacial crosslinking to ultimately enhance crack onset strain.