TY - JOUR
T1 - Remolding and Deconstruction of Industrial Thermosets via Carboxylic Acid-Catalyzed Bifunctional Silyl Ether Exchange
AU - Husted, Keith E.L.
AU - Brown, Christopher M.
AU - Shieh, Peyton
AU - Kevlishvili, Ilia
AU - Kristufek, Samantha L.
AU - Zafar, Hadiqa
AU - Accardo, Joseph V.
AU - Cooper, Julian C.
AU - Klausen, Rebekka S.
AU - Kulik, Heather J.
AU - Moore, Jeffrey S.
AU - Sottos, Nancy R.
AU - Kalow, Julia A.
AU - Johnson, Jeremiah A.
N1 - Publisher Copyright:
© 2023 American Chemical Society.
PY - 2023/1/25
Y1 - 2023/1/25
N2 - Convenient strategies for the deconstruction and reprocessing of thermosets could improve the circularity of these materials, but most approaches developed to date do not involve established, high-performance engineering materials. Here, we show that bifunctional silyl ether, i.e., R′O-SiR2-OR′′, (BSE)-based comonomers generate covalent adaptable network analogues of the industrial thermoset polydicyclopentadiene (pDCPD) through a novel BSE exchange process facilitated by the low-cost food-safe catalyst octanoic acid. Experimental studies and density functional theory calculations suggest an exchange mechanism involving silyl ester intermediates with formation rates that strongly depend on the Si-R2 substituents. As a result, pDCPD thermosets manufactured with BSE comonomers display temperature- and time-dependent stress relaxation as a function of their substituents. Moreover, bulk remolding of pDCPD thermosets is enabled for the first time. Altogether, this work presents a new approach toward the installation of exchangeable bonds into commercial thermosets and establishes acid-catalyzed BSE exchange as a versatile addition to the toolbox of dynamic covalent chemistry.
AB - Convenient strategies for the deconstruction and reprocessing of thermosets could improve the circularity of these materials, but most approaches developed to date do not involve established, high-performance engineering materials. Here, we show that bifunctional silyl ether, i.e., R′O-SiR2-OR′′, (BSE)-based comonomers generate covalent adaptable network analogues of the industrial thermoset polydicyclopentadiene (pDCPD) through a novel BSE exchange process facilitated by the low-cost food-safe catalyst octanoic acid. Experimental studies and density functional theory calculations suggest an exchange mechanism involving silyl ester intermediates with formation rates that strongly depend on the Si-R2 substituents. As a result, pDCPD thermosets manufactured with BSE comonomers display temperature- and time-dependent stress relaxation as a function of their substituents. Moreover, bulk remolding of pDCPD thermosets is enabled for the first time. Altogether, this work presents a new approach toward the installation of exchangeable bonds into commercial thermosets and establishes acid-catalyzed BSE exchange as a versatile addition to the toolbox of dynamic covalent chemistry.
UR - http://www.scopus.com/inward/record.url?scp=85146345920&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85146345920&partnerID=8YFLogxK
U2 - 10.1021/jacs.2c11858
DO - 10.1021/jacs.2c11858
M3 - Article
C2 - 36637230
AN - SCOPUS:85146345920
SN - 0002-7863
VL - 145
SP - 1916
EP - 1923
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 3
ER -