Abstract
Polyurethanes (PUs) are versatile polymers widely used in coatings,
elastomers, adhesives, and foams due to their diverse properties. Designing PUs with
enhanced functionality and recyclability is essential to developing sustainable
materials. In this study, apolar acetal-containing polyols (APs) were developed via a
scalable polycondensation process using long-chain aliphatic aldehydes and diols.
These APs enabled the straightforward synthesis of PUs with very low surface
polarity, low glass transition temperatures, excellent mechanical performance, and
high hydrolytic stability. Importantly, the incorporation of cleavable acetal bonds
allowed closed-loop recycling of the PUs under mild acidic conditions, enabling high yield recovery of monomers. To demonstrate their versatility, the APs were used in two-component PU coatings, which exhibited strong adhesion to aluminum, superior hydrophobicity (contact angles >97°), and efficient debonding under environmentally benign conditions. This work underscores the potential of acetal-containing polyols to address environmental challenges by combining innovative material design with sustainable recycling pathways, advancing the development of recyclable PUs for applications in coatings, compact materials, foams, and adhesives.
elastomers, adhesives, and foams due to their diverse properties. Designing PUs with
enhanced functionality and recyclability is essential to developing sustainable
materials. In this study, apolar acetal-containing polyols (APs) were developed via a
scalable polycondensation process using long-chain aliphatic aldehydes and diols.
These APs enabled the straightforward synthesis of PUs with very low surface
polarity, low glass transition temperatures, excellent mechanical performance, and
high hydrolytic stability. Importantly, the incorporation of cleavable acetal bonds
allowed closed-loop recycling of the PUs under mild acidic conditions, enabling high yield recovery of monomers. To demonstrate their versatility, the APs were used in two-component PU coatings, which exhibited strong adhesion to aluminum, superior hydrophobicity (contact angles >97°), and efficient debonding under environmentally benign conditions. This work underscores the potential of acetal-containing polyols to address environmental challenges by combining innovative material design with sustainable recycling pathways, advancing the development of recyclable PUs for applications in coatings, compact materials, foams, and adhesives.
| Original language | English |
|---|---|
| Pages (from-to) | 6055-6066 |
| Number of pages | 12 |
| Journal | ACS Applied Polymer Materials |
| Volume | 7 |
| Issue number | 10 |
| Early online date | 12 May 2025 |
| DOIs | |
| Publication status | Published - 23 May 2025 |
Funding
The authors would like to thank Xianwen Lou (TU Eindhoven) for MALDI-TOF-MS measurements, Berend Eling (TU Eindhoven) for scientific discussions, and Luuk Moone (TU Eindhoven) for his assistance with the DVS measurements. The authors acknowledge financial support from BASF Polyurethanes GmbH (Germany) and the Dutch Ministry of Economic Affairs and Climate Policy (TKI project CHEMIE.PGT.2020.022).
| Funders | Funder number |
|---|---|
| BASF | |
| Ministerie van Economische Zaken en Klimaat | CHEMIE.PGT.2020.022 |
Keywords
- acetal
- closed-loop recycling
- hydrophobic coatings
- polyurethane
- solvent-free polycondensation