{"title":"Polyurethanes synthesized from diisocyanate trimers and polyethylene glycol undergo crosslinking via thermally reversible Diels–Alder reactions","authors":"Heru Santoso, Sabrina Aufar Salma, Frita Yuliati, Shayrilla Chairunnisa Nur Afifa, Sumarno Sumarno","doi":"10.1007/s13233-025-00400-y","DOIUrl":null,"url":null,"abstract":"<div><p>A series of self-healing polyurethane (PU) polymers were synthesized via the Diels–Alder reaction between the furan-functionalized PU prepolymer and bismaleimide (BMI). The PU prepolymer is a reaction product of polyethylene glycol (PEG) and a pentamethylene diisocyanate trimer (PDI-t). Furfuryl amine was attached to the terminal isocyanic groups of PU, resulting in furfuryl amine polyurethane (PU-FA). PU-FA was cross-linked via dynamic bonds between the furan groups and BMI, generating reversible bonds with the material. This study explored reversible polymer networks under various thermal conditions, including different reaction parameters, prepolymer ratios, and healing temperatures, to evaluate the healing capabilities of these polymers. The results demonstrated that PU-DA exhibits thermal reversibility, as evidenced by the appearance of an endothermic peak in the DSC analysis, indicating bond cleavage via the retro-Diels–Alder (r-DA) reaction. This endothermic peak re-emerged after cooling at 70 °C for 24 h, further confirming the reversibility of the reaction. Additionally, crack healing in the PU-DA film was facilitated by the synergistic effects of the thermally reversible Diels–Alder reaction and the thermal mobility of molecular chains. The self-healing performance evaluation revealed that PU-DA samples with an NCO/OH ratio of 1.5 exhibited a reduction in tensile strength after healing compared to the original PU-DA specimens before heat treatment. Conversely, samples with an NCO/OH ratio of 3 demonstrated a healing efficiency exceeding 100%, attributed to the enhanced cross-link density, which contributed to a more robust network structure.</p><h3>Graphical abstract</h3>\n<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div><p>In this study, self-healing Diels-Alder polyurethane (PU-DA) was successfully synthesized using PDI trimer. The findings confirmed that the material's healing mechanism is activated by the reversible interaction between furan and maleimide groups within PU-DA, enabling it to autonomously repair structural damage</p></div>","PeriodicalId":688,"journal":{"name":"Macromolecular Research","volume":"33 8","pages":"1015 - 1028"},"PeriodicalIF":3.4000,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Macromolecular Research","FirstCategoryId":"5","ListUrlMain":"https://link.springer.com/article/10.1007/s13233-025-00400-y","RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"POLYMER SCIENCE","Score":null,"Total":0}
引用次数: 0
Abstract
A series of self-healing polyurethane (PU) polymers were synthesized via the Diels–Alder reaction between the furan-functionalized PU prepolymer and bismaleimide (BMI). The PU prepolymer is a reaction product of polyethylene glycol (PEG) and a pentamethylene diisocyanate trimer (PDI-t). Furfuryl amine was attached to the terminal isocyanic groups of PU, resulting in furfuryl amine polyurethane (PU-FA). PU-FA was cross-linked via dynamic bonds between the furan groups and BMI, generating reversible bonds with the material. This study explored reversible polymer networks under various thermal conditions, including different reaction parameters, prepolymer ratios, and healing temperatures, to evaluate the healing capabilities of these polymers. The results demonstrated that PU-DA exhibits thermal reversibility, as evidenced by the appearance of an endothermic peak in the DSC analysis, indicating bond cleavage via the retro-Diels–Alder (r-DA) reaction. This endothermic peak re-emerged after cooling at 70 °C for 24 h, further confirming the reversibility of the reaction. Additionally, crack healing in the PU-DA film was facilitated by the synergistic effects of the thermally reversible Diels–Alder reaction and the thermal mobility of molecular chains. The self-healing performance evaluation revealed that PU-DA samples with an NCO/OH ratio of 1.5 exhibited a reduction in tensile strength after healing compared to the original PU-DA specimens before heat treatment. Conversely, samples with an NCO/OH ratio of 3 demonstrated a healing efficiency exceeding 100%, attributed to the enhanced cross-link density, which contributed to a more robust network structure.
Graphical abstract
In this study, self-healing Diels-Alder polyurethane (PU-DA) was successfully synthesized using PDI trimer. The findings confirmed that the material's healing mechanism is activated by the reversible interaction between furan and maleimide groups within PU-DA, enabling it to autonomously repair structural damage
期刊介绍：
Original research on all aspects of polymer science, engineering and technology, including nanotechnology
Presents original research articles on all aspects of polymer science, engineering and technology
Coverage extends to such topics as nanotechnology, biotechnology and information technology
The English-language journal of the Polymer Society of Korea
Macromolecular Research is a scientific journal published monthly by the Polymer Society of Korea. Macromolecular Research publishes original researches on all aspects of polymer science, engineering, and technology as well as new emerging technologies using polymeric materials including nanotechnology, biotechnology, and information technology in forms of Articles, Communications, Notes, Reviews, and Feature articles.
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