Pendant Group Modifications Provide Graft Copolymer Silicones with Exceptionally Broad Thermomechanical Properties.

Autor:	Husted KEL; Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States., Herzog-Arbeitman A; Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States., Kleinschmidt D; Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States., Zhang W; Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States., Sun Z; Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States., Fielitz AJ; Core R&D, Analytical Science, The Dow Chemical Company, Midland, Michigan 48640, United States., Le AN; Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06520, United States., Zhong M; Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06520, United States., Johnson JA; Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.
Jazyk:	angličtina
Zdroj:	ACS central science [ACS Cent Sci] 2022 Dec 23; Vol. 9 (1), pp. 36-47. Date of Electronic Publication: 2022 Dec 23 (Print Publication: 2023).
DOI:	10.1021/acscentsci.2c01246
Abstrakt:	Graft copolymers offer a versatile platform for the design of self-assembling materials; however, simple strategies for precisely and independently controlling the thermomechanical and morphological properties of graft copolymers remain elusive. Here, using a library of 92 polynorbornene- graft -polydimethylsiloxane (PDMS) copolymers, we discover a versatile backbone-pendant sequence-control strategy that addresses this challenge. Small structural variations of pendant groups, e.g., cyclohexyl versus n -hexyl, of small-molecule comonomers have dramatic impacts on order-to-disorder transitions, glass transitions, mechanical properties, and morphologies of statistical and block silicone-based graft copolymers, providing an exceptionally broad palette of designable materials properties. For example, statistical graft copolymers with high PDMS volume fractions yielded unbridged body-centered cubic morphologies that behaved as soft plastic crystals. By contrast, lamellae-forming graft copolymers provided robust, yet reprocessable silicone thermoplastics (TPs) with transition temperatures spanning over 160 °C and elastic moduli as high as 150 MPa despite being both unentangled and un-cross-linked. Altogether, this study reveals a new pendant-group-mediated self-assembly strategy that simplifies graft copolymer synthesis and enables access to a diverse family of silicone-based materials, setting the stage for the broader development of self-assembling materials with tailored performance specifications. Competing Interests: The authors declare no competing financial interest. (© 2022 The Authors. Published by American Chemical Society.)
Databáze:	MEDLINE
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