Degradable π-Conjugated Polymers

Abstract

The integration of next-generation electronics into society is rapidly reshaping our daily interactions and lifestyles, revolutionizing communication and engagement with the world. Future electronics promise stimuli-responsive features and enhanced biocompatibility, such as skin-like health monitors and sensors embedded in food packaging, transforming healthcare and reducing food waste. Imparting degradability may reduce the adverse environmental impact of next-generation electronics and lead to opportunities for environmental and health monitoring. While advancements have been made in producing degradable materials for encapsulants, substrates, and dielectrics, the availability of degradable conducting and semiconducting materials remains restricted. π-Conjugated polymers are promising candidates for the development of degradable conductors or semiconductors due to the ability to tune their stimuli-responsiveness, biocompatibility, and mechanical durability. This perspective highlights three design considerations: the selection of π-conjugated monomers, synthetic coupling strategies, and degradation of π-conjugated polymers, for generating π-conjugated materials for degradable electronics. We describe the current challenges with monomeric design and present options to circumvent these issues by highlighting biobased π-conjugated compounds with known degradation pathways and stable monomers that allow for chemically recyclable polymers. Next, we present coupling strategies that are compatible for the synthesis of degradable π-conjugated polymers, including direct arylation polymerization and enzymatic polymerization. Lastly, we discuss various modes of depolymerization and characterization techniques to enhance our comprehension of potential degradation byproducts formed during polymer cleavage. Our perspective considers these three design parameters in parallel rather than independently while having a targeted application in mind to accelerate the discovery of next-generation high-performance πconjugated polymers for degradable organic electronics.

Understanding Degradation Dynamics of Azomethine-containing Conjugated Polymers

“…Electronic devices are traditionally made of inorganic semiconducting materials that are often toxic and require harsh/hazardous conditions to recover raw materials after devices are disposed. , The growing consumption of electronics also raises concerns about the environmental impact of discarded inorganic components. , With end-of-life considerations in mind, researchers are inspired to focus efforts toward the development of organic semiconductors for transient electronic devices. − While conjugated polymers are not inherently benign to the environment, they have the potential to be degradable and are envisioned to leave a smaller ecological footprint compared to inorganic counterparts. − Conjugated polymers also offer a number of advantages, including solution processability and tailorable optoelectronic properties, that make them particularly compelling as active-layer materials for flexible devices. , Furthermore, these polymers can be modified through the choice of comonomer or side chains to produce materials suited for myriad applications with tailorable solubility and aqueous/biocompatibility. − For these reasons, there is a need to gain fundamental insight into the properties of degradable conjugated polymers in order to support the continued development of materials with closed-loop life cycles for electronic devices.…”

“… 5 − 7 While conjugated polymers are not inherently benign to the environment, they have the potential to be degradable and are envisioned to leave a smaller ecological footprint compared to inorganic counterparts. 8 − 10 Conjugated polymers also offer a number of advantages, including solution processability and tailorable optoelectronic properties, that make them particularly compelling as active-layer materials for flexible devices. 11 , 12 Furthermore, these polymers can be modified through the choice of comonomer or side chains to produce materials suited for myriad applications with tailorable solubility and aqueous/biocompatibility.…”