Polyester networks from structurally similar monomers: recyclable-by-design and upcyclable to photopolymers

Abstract

Epoxy-based polymer networks from step-growth polymerizations are ubiquitous in coatings, adhesives, and as matrices in composite materials. Dynamic covalent bonds in the network allow its degradation into small molecules and...

Photopatternable, Degradable, and Performant Polyimide Network Substrates for E-Waste Mitigation

“…Inspired by Cho et al and our previous work, we stimulate the transesterification reaction with methanol using potassium carbonate (K 2 CO 3 ) as the catalyst. 30,52 Unfortunately, at relevant disc dimension (e.g. 10mm diameter by 2 mm thick) the depolymerization, although successful, can take over a week to complete due to the limited diffusion of methanol into the glassy polymer network.…”

“…[24][25][26] As an alternative, crosslinked polyesters can be formed efficiently at room temperature neat with mild conditions. [27][28][29][30] By comparison, polyimide (PI), particularly aromatic polyimides like Kapton®, is a popular substrate in today's electronic devices due to their unique combination of outstanding mechanical properties including tensile modulus ~ 2 GPa; ultimate tensile strength ~ 230 MPa; ultimate elongation ~ 70%, thermal stability from -250°C < T < 300 °C; relatively high thermal conductivity ~ 0.12 Wm -1 K -1 ; low coefficient of thermal expansion (CTE) ~ 20 ppm °C-1 ; high glass transition temperature, T g > 300 °C, high dielectric constant (DK or ε r ), of 3.5 at 1kHz; and low dielectric loss (DF or tan δ) of 0.002 at 1 kHz. 31,32 Consequently, PIs are ideal substrates for robust, high density, miniaturized circuits, particularly since the superb electrical barrier performance persists in thin film form factors for flexible electronics.…”

Ductile Glassy Polymer Networks Capable of Large Plastic Deformation and Elastic Recovery

“…66 Inspired by work from Cho et al and our previous work, we attempted to degrade the polyamide photopolymers that contains ample ester groups from the thiol monomers, using potassium carbonate (K2CO3) and methanol at ambient conditions. 74,75 Bulk polymer samples were placed in saturated K2CO3 methanol solutions and degraded completely in 24 hours. Chemical analysis using 1 H-NMR of the resulting small molecules revealed the formation of methyl esters at 3.68 ppm with an integration https://doi.org/10.26434/chemrxiv-2024-zvl4w ORCID: https://orcid.org/0000-0001-5812-5787 Content not peer-reviewed by ChemRxiv.…”

Directing network degradability using wavelength-selective thiol-acrylate photopolymerization

“…, stimuli-responsive behavior) into these multimaterials in a programmable manner. Herein, we focus on combining wavelength-selective photopolymerization with dynamic covalent chemistry 36–47 to impart stimuli-responsive degradability into specific regions of the resulting multimaterials. In our previous study, we developed degradable crosslinked thiol–ene photopolymers that contain dynamic disulfide bonds from commercially available building blocks including Thioplast G4, a reactive difunctional thiol comprising internal disulfide bonds.…”