Enhanced thermomechanical property of a self-healing polymer self-assembly of a reversibly cross-linkable block copolymer

• Published in: Polymer chemistry Vol. 11; no. 22; pp. 371 - 378
• Main Authors: Lee, Hyang Moo, Perumal, Suguna, Kim, Gi Young, Kim, Jin Chul, Kim, Young-Ryul, Kim, Minsoo P, Ko, Hyunhyup, Rho, Yecheol, Cheong, In Woo
• Format: Journal Article
• Language: English
• Published: 09.06.2020
• ISSN: 1759-9954; 1759-9962
• DOI: 10.1039/d0py00310g

We report the preparation and thermomechanical properties of hetero-nanostructured self-healing polymers (HSPs) bearing a hindered urea bond (HUB) by varying the content of a self-healable block copolymer (BCP). The micellar morphology of the BCP blend in a matrix polymer was studied using transmission electron microscopy and grazing-incidence small-angle X-ray scattering with various organic solvent types and BCP contents. The self-healing efficiency of the HSPs was obtained from single-scratch tests through optical microscopy and atomic force microscopy. To confirm self-healing at the molecular level, the mechanical properties of the cross-cut and healed HSPs were also analyzed using a universal testing machine. Thermomechanical properties associated with HUB were measured by dynamic mechanical analysis and temperature-oscillating rheometry. The results showed that blending the BCP improved the toughness, the hardness, and the modulus up to 21.7, 25.3, and 24.8%, respectively. Moreover, at high temperatures, the temperature range of the rubbery plateau was greatly widened without a noticeable decrease in the self-healing capability. Introduction of a self-healable block copolymer increases the mechanical property whilst maintaining self-healing efficiency.