Biobased Thermoset Substrate for Flexible and Sustainable Organic Photovoltaics

Abstract

Toward a sustainable development of the flexible electronics industry, the design and facile preparation of sustainable flexible substrates with satisfactory mechanical properties and transparency is still a challenge. Herein, taking structural advantages of biobased eugenol and vanillin, a polymerizable aromatic carbonate monomer with α,ω‐diene functionality (2E), and a robust aromatic acetal monomer with α,ω‐tetraene functionality (4E), are designed and prepared. Then, they are cross‐linked with pentaerythritol tetrakis(2‐mercaptoacetate) (4SH) via thiol‐ene click reaction to generate a series of ternary poly(thioether carbonate acetal) thermosets. It is found that the introduction of 4E allows the production of thiol‐ene thermosets with higher crosslink density, which can balance their mechanical, optical, and surface properties. In addition, the thermoset shows good resistance against various natural environmental conditions and can be decomposed into recyclable small molecules under harsher conditions (3 m NaOH, 80 °C). As a result, the optimal thermoset is well‐suited for the fabrication of flexible organic solar cells (OSCs), yielding a power conversion efficiency of 15.41%, which is superior to polyethylene terephthalate‐based OSC. The results provided significant insights for the design and preparation of sustainable polymer substrates for OSCs, even flexible electronics.

Biosustainable Multiscale Transparent Nanocomposite Films for Sensitive Pressure and Humidity Sensors

“…The new generation of flexible electronic device substrates is dedicated to developing biocompatible, sustainable, low-cost, and high-performance flexible materials . Some biodegradable plastics essentially satisfy the condition of a flexible electronic device substrate . However, such biodegradable plastics’ thermal stability and mechanical properties are inappropriate for long-term use as flexible substrates.…”

Biobased Thiol-ene Networks with High Optical Transparency and Abbe Number Derived from Citric Acid

“…Due to the step-growth radical polymerization mechanism, the thiol-ene photopolymerization generally shows reduced volume shrinkage and a delayed vitrification process, which is crucial for producing robust polymers with high dimensional stability . From a material design perspective, incorporating highly polarizable sulfur atoms is advantageous to obtain polymers with inherently high n values. , In recent years, several sulfur-containing systems like polyimide, poly(phenylene thioether), poly(thioester)s, , and poly(thioether sulfone) have been developed. , However, one limitation of the thiol-ene networks is their rubbery nature with limited T g due to the presence of abundant flexible thioether linkages. − This hinders applications where high mechanical properties and high T g values are priority requirements. One feasible strategy is to introduce highly rigid and multifunctional monomers into polymers to overcome the flexibility of thioether linkages …”