Direct Monomer Recovery from Ring-Closing Depolymerization of Thermosets DOI Creative Commons
Chihui Zheng, Gadi Slor, Youwei Ma

et al.

ACS Macro Letters, Journal Year: 2024, Volume and Issue: unknown, P. 1704 - 1710

Published: Dec. 7, 2024

Recovering monomers from the depolymerization of thermosets presents a significant challenge, which becomes even more daunting if one sets goal doing it directly, i.e., without complex chemical separation steps. To this end, we have synthesized new type polycarbonate thermoset by first copolymerizing alkyl cyclic carbonates (ACCs) with small amounts allyloxy (AoCCs), followed cross-linking resulting excess tetrathiol compounds under UV irradiation. These cross-linked polycarbonates demonstrate enhanced thermal and mechanical properties compared to their linear analogues, while maintaining polymers' capacity for ring-closing depolymerization. The process enables direct recovery ACC its dimer, bypassing steps that are commonly employed in recycling conventional chemically recyclable thermosets. yields range 74.7% 91.7% depending on ratios AoCC Furthermore, recovered can be repolymerized AoCCs leading same quality initially one.

Language: Английский

Structure–Property Relationships of Elastomeric Vinylogous Urethane Thermosets and Their Application as Closed-Loop Recyclable Strain Sensors DOI Creative Commons
Youwei Ma, Francesco Stellacci

Macromolecules, Journal Year: 2025, Volume and Issue: 58(4), P. 1923 - 1934

Published: Feb. 5, 2025

Developing closed-loop recyclable thermosets and understanding their structure–property relationships are essential steps in advancing a circular materials economy. Here, we present vinylogous urethane (VU) thermoset with recyclability, synthesized through the reaction of polytetrahydrofuran bisacetoacetate (aPTHF) tris(2-aminoethyl)amine (TREN). These VU polymers exhibit high elasticity, only 3–9% residual strain observed after cyclic tensile testing at maximum 100%, depending on molecular weight aPTHF network cross-link density. The two structural parameters also allow modulation mechanical stress-relaxation properties elastomers. To investigate hydrolysis linkages within hydrophobic matrix, employed heterogeneous system using biphasic mixture HCl CDCl3. Our findings show that VUs remain stable pure water but can be dissociated under acidic conditions, dissociation rate accelerated higher temperatures and/or presence concentrations. detailed investigations indicate potential elastomers as sustainable substrates for wearable sensors. We therefore conduct case study synthesizing sensor incorporation multiwalled carbon nanotubes (MCNs) into elastomer matrix. robustly detect various movements. Moreover, treatment both neat polymer composite diethyl ether solvent allows excellent recovery (>90%) TREN (86%), without discernible damage to MCNs reclaimed from latter.

Language: Английский

Citations

2

A Transparent, Abrasion‐Resistant Anti‐Fog Coating on Glass Substrates DOI Open Access
Sijia Yang, Song Xiao, Ran Wei

et al.

Journal of Applied Polymer Science, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 7, 2025

ABSTRACT The formation of fog on the surface transparent glass severely reduces its transmittance, which limits application in medical devices, optical instruments, and other industries that require high transmittance. A new transparent, water‐resistant, abrasion‐resistant PVA anti‐fog coating based polyvinyl alcohol (PVA), 5‐sulfosalicylic acid (SAD), ammonium persulfate (APS) was developed this study. hydroxyl, carboxyl, sulfonic groups SAD molecule can form dense hydrogen bonds with hydroxyl side chain, increases water resistance coating. APS, as a free radical initiator, produce sulfate radicals during thermal curing eventually cross‐linked structure main carbon thereby further improving resistance, friction stability experimental results show modified by not only has excellent light transmittance performance but also good abrasion stability. In addition, preparation method hydrophilic is simple convenient, nontoxic environmentally friendly used solvent, expected to be large‐scale industrial production.

Language: Английский

Citations

0

Direct Monomer Recovery from Ring-Closing Depolymerization of Thermosets DOI Creative Commons
Chihui Zheng, Gadi Slor, Youwei Ma

et al.

ACS Macro Letters, Journal Year: 2024, Volume and Issue: unknown, P. 1704 - 1710

Published: Dec. 7, 2024

Recovering monomers from the depolymerization of thermosets presents a significant challenge, which becomes even more daunting if one sets goal doing it directly, i.e., without complex chemical separation steps. To this end, we have synthesized new type polycarbonate thermoset by first copolymerizing alkyl cyclic carbonates (ACCs) with small amounts allyloxy (AoCCs), followed cross-linking resulting excess tetrathiol compounds under UV irradiation. These cross-linked polycarbonates demonstrate enhanced thermal and mechanical properties compared to their linear analogues, while maintaining polymers' capacity for ring-closing depolymerization. The process enables direct recovery ACC its dimer, bypassing steps that are commonly employed in recycling conventional chemically recyclable thermosets. yields range 74.7% 91.7% depending on ratios AoCC Furthermore, recovered can be repolymerized AoCCs leading same quality initially one.

Language: Английский

Citations

1