Tuning crosslinking of hybrid preceramic polymers in vat photopolymerization toward controlled ceramic yields
Sungjin Kim, Catherine Biju, Menisha S. Karunarathna, Niya Y. Grimes, Nadim S. Hmeidat, July Reyes-Zacarias, Shradha Agarwal, Md Anisur Rahman, Dustin Gilmer, Brett G. Compton, Steve E. Bullock, Tomonori Saito, Corson L. Cramer
Abstract
• Digital Light Processing (DLP) is utilized as a versatile platform to control preceramic polymer crosslinking and ceramic yield in polymer-derived ceramics (PDC) engineering. • A correlation between pre-pyrolysis crosslinking density represented by stiffness and post-pyrolysis ceramic yield is established, offering a fast, non-destructive, energy-efficient method to predict and improve ceramic yield. • Through rational design and tuning of photochemical crosslinking, ceramic yield is enhanced from 64% to over 86%, even with increasing inclusion of volatile elements. • A one-pot thiol-ene hybridization of polycarbosilane and polycarbosiloxane using DLP epitomizes an effective strategy to combine diverse preceramic polymers. • The findings contribute to developing more sustainable methods for preceramic polymer processing and advanced organic–inorganic materials engineering. Control of preceramic polymer crosslinking for UV-curable processing is essential for fine 3D printing with high ceramic conversion for sustainable polymer-derived ceramics (PDC) engineering. While various factors influencing ceramic yield have been studied, the systematic exploration of the relationship between crosslinking and ceramic yield, especially when crosslinking increases volatile elements, remains open for further investigation. This study addresses this gap by utilizing vat photopolymerization (VP) additive manufacturing (AM) as a versatile platform for controlling preceramic crosslinking and ceramic yield. By rationally designing and tuning the photochemical crosslinking through digital light processing (DLP), we demonstrate that the ceramic yield can be enhanced from 64% to over 86%, even with added volatile elements. We reveal that the post-pyrolysis ceramic yield can be closely correlated with the pre-pyrolysis crosslinking of the preceramic network represented by its stiffness. This correlation thereby suggests a fast, energy-efficient, non-destructive methodology to predict and improve ceramic yield. Combined with these findings, our one-pot thiol-ene hybridization of polycarbosilane and polycarbosiloxane via DLP offers an exemplary method to generate hybrid preceramic polymers with tailored material properties toward target applications, and potentially even higher ceramic yields. This study thus contributes to achieving better resource- and energy-efficient preceramic polymer and PDC processing routes toward sustainable, advanced organic–inorganic materials manufacturing.