ACS Macro LettersPub Date : 2025-07-15Epub Date: 2025-07-04DOI: 10.1021/acsmacrolett.5c00267
Dana Ezzeddine, Daniel C Barzycki, Ralm G Ricarte
{"title":"Impact of Cross-Link Density on Polybutadiene Permanent and Vitrimer Networks.","authors":"Dana Ezzeddine, Daniel C Barzycki, Ralm G Ricarte","doi":"10.1021/acsmacrolett.5c00267","DOIUrl":"10.1021/acsmacrolett.5c00267","url":null,"abstract":"<p><p>Vitrimers are polymer networks that undergo structural rearrangement through dynamic associative bond exchange without compromising the overall topological connectivity. In this study, we investigate the impact of cross-link density on the structural, viscoelastic, and glass transition properties of both vitrimer and permanent networks. We synthesized polybutadiene (PB) networks using a photoinitiated thiol-ene click reaction to incorporate either dynamic dioxaborolane or permanent 1,4-benzenedimethanethiol cross-links, with the number of cross-links per chain ranging from 2 to 15. To quantify the actual cross-link density, we developed a network disassembly procedure in which an excess of 1,2-octanediol de-cross-links the PB vitrimer, after which the resulting fragments are analyzed using <sup>1</sup>H nuclear magnetic resonance spectroscopy. Although both networks exhibit identical gel fractions, small-amplitude oscillatory shear measurements combined with phantom network theory analysis reveal that vitrimers have a higher effective cross-link density than do their permanent counterparts. Vapor swelling experiments further indicated that PB vitrimers have fewer defects than permanently cross-linked networks. Differential scanning calorimetry demonstrated that vitrimers and permanent networks exhibit distinct relationships between the glass transition temperature and cross-link density. Overall, our findings underscore the significant influence of dynamic associative cross-links on the behavior and performance of elastomeric materials.</p>","PeriodicalId":18,"journal":{"name":"ACS Macro Letters","volume":" ","pages":"1011-1018"},"PeriodicalIF":5.1,"publicationDate":"2025-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144564148","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ACS Macro LettersPub Date : 2025-07-15Epub Date: 2025-06-27DOI: 10.1021/acsmacrolett.5c00244
Lillian E Mortensen, Fernando Enriquez Barrero, Talaial B Alina, Jennifer N Cha, Andrew P Goodwin
{"title":"Temperature-Responsive Rheology Modifiers from Cellulose to Enable Acoustic Additive Manufacturing of Hydrogels.","authors":"Lillian E Mortensen, Fernando Enriquez Barrero, Talaial B Alina, Jennifer N Cha, Andrew P Goodwin","doi":"10.1021/acsmacrolett.5c00244","DOIUrl":"10.1021/acsmacrolett.5c00244","url":null,"abstract":"<p><p>While photopolymerization is a widely adopted method for additive manufacturing, its versatility is limited by high attenuation by the polymerization medium, which leads to anisotropic parts and slow printing times. Ultrasound bypasses these depth limitations, but challenges of acoustic streaming and heat localization remain. Here, we investigated a single-phase system that integrates temperature-responsive rheology modifiers to enhance ultrasound-based additive manufacturing. We employed cellulose derivatives with lower critical solution temperatures (LCST) to restrict acoustic streaming and localize heat within the focal zone. Our findings show that these rheology modifiers effectively contain heat, minimizing bulk polymerization and enhancing printing precision. Hydroxypropyl cellulose (HPC)-based sono-inks enable rapid printing speeds of up to 60 mm/min with sub-5 mm resolution. Furthermore, HPC inks demonstrated the capability to print at a distance and through optically opaque tissues. Conversely, methylcellulose (MC) formulations improved printing resolution but reduced speed, likely because the LCST could not be reached during the printing process. The developed sono-ink holds promise for future applications such as <i>in vivo</i> 3D printing, volumetric fabrication, and composite material synthesis.</p>","PeriodicalId":18,"journal":{"name":"ACS Macro Letters","volume":" ","pages":"976-982"},"PeriodicalIF":5.1,"publicationDate":"2025-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144511249","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ACS Macro LettersPub Date : 2025-07-15Epub Date: 2025-06-30DOI: 10.1021/acsmacrolett.5c00317
Chaninya Mak-Iad, Luca Bertossi, Georges J M Formon, Christoph Weder
{"title":"Healable Glassy Metallosupramolecular Polymers.","authors":"Chaninya Mak-Iad, Luca Bertossi, Georges J M Formon, Christoph Weder","doi":"10.1021/acsmacrolett.5c00317","DOIUrl":"10.1021/acsmacrolett.5c00317","url":null,"abstract":"<p><p>Metallosupramolecular polymers (MSPs), formed through ligand-metal coordination, feature dynamic bonds that enable damage repair <i>via</i> reversible dissociation. Here, we report the synthesis of healable MSPs by modifying commercially available glycol-modified polyethylene terephthalate (PETG), an amorphous commodity polyester known for its durability, chemical resistance, and formability. The new materials were accessed through the Zn-catalyzed transesterification of PETG with ethylene glycol, end-functionalization of the resulting homobifunctional oligomers with the 2,6-bis(1'-methylbenzimidazolyl)pyridine (Mebip) ligand, and subsequent assembly of these macromonomers into MSPs <i>via</i> Zn<sup>2+</sup> complexation. One of the MSPs made offers an attractive combination of high tensile strength (31 MPa), high Young's Modulus (1 GPa), and excellent healability (94% in 2.5 min).</p>","PeriodicalId":18,"journal":{"name":"ACS Macro Letters","volume":" ","pages":"996-1003"},"PeriodicalIF":5.1,"publicationDate":"2025-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12269065/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144525310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chaninya Mak-iad, Luca Bertossi, Georges J. M. Formon* and Christoph Weder*,
{"title":"","authors":"Chaninya Mak-iad, Luca Bertossi, Georges J. M. Formon* and Christoph Weder*, ","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":18,"journal":{"name":"ACS Macro Letters","volume":"14 7","pages":"XXX-XXX XXX-XXX"},"PeriodicalIF":5.1,"publicationDate":"2025-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/pdf/10.1021/acsmacrolett.5c00317","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144623023","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dana Ezzeddine, Daniel C. Barzycki and Ralm G. Ricarte*,
{"title":"","authors":"Dana Ezzeddine, Daniel C. Barzycki and Ralm G. Ricarte*, ","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":18,"journal":{"name":"ACS Macro Letters","volume":"14 7","pages":"XXX-XXX XXX-XXX"},"PeriodicalIF":5.1,"publicationDate":"2025-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/pdf/10.1021/acsmacrolett.5c00267","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144623029","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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