{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,4]],"date-time":"2026-06-04T10:35:29Z","timestamp":1780569329837,"version":"3.54.1"},"reference-count":34,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2025,6,12]],"date-time":"2025-06-12T00:00:00Z","timestamp":1749686400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Petr\u00f3leo Brasileiro S.A. (PETROBRAS)","award":["0050.0119730.21.9"],"award-info":[{"award-number":["0050.0119730.21.9"]}]},{"name":"Petr\u00f3leo Brasileiro S.A. (PETROBRAS)","award":["308760\/2022-0"],"award-info":[{"award-number":["308760\/2022-0"]}]},{"name":"Conselho Nacional de Desenvolvimento Cient\u00edfico e Tecnol\u00f3gico (CNPq)","award":["0050.0119730.21.9"],"award-info":[{"award-number":["0050.0119730.21.9"]}]},{"name":"Conselho Nacional de Desenvolvimento Cient\u00edfico e Tecnol\u00f3gico (CNPq)","award":["308760\/2022-0"],"award-info":[{"award-number":["308760\/2022-0"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Polymers"],"abstract":"<jats:p>Polyamides (PAs) are widely used as barrier materials in offshore oil and gas (O&amp;G) equipment due to their mechanical strength and chemical resistance. However, long-term exposure to hydrogen sulfide scavengers (H2S-SCVs) may significantly affect their physicochemical properties. Previous studies using thermal analysis and 1H time-domain NMR (1H TD-NMR) suggest that ethoxylated H2S-SCVs impose molecular constraints, increasing the glass transition temperature (Tg) and reducing chain mobility above Tg. The present study builds upon these findings using a multi-technique analytical approach, including FTIR, Raman, 1H DQ-TD-NMR, and 13C solid-state NMR (ssNMR), to provide a more comprehensive understanding of the molecular alterations in PA materials. The results clearly demonstrate that H2S-SCV exposure leads to the progressive exudation of plasticizers from the PA matrix. This plasticizer loss is a key factor contributing to the observed shift in Tg and the reduction in molecular mobility. 1H DQ-TD-NMR data confirmed an increase in the density of dynamically constrained chains over time and allowed for the characterization of heterogeneity in these constraints throughout the PA matrix. Moreover, 13C ssNMR spectra revealed the presence of immobilized H2S-SCV chemical groups within the polymer matrix, strongly supporting the early statement that the mobility constraints observed in 1H DQ-TD-NMR are associated with the formation of crosslinks induced by the H2S-SCV: H2S-SCV acts as a crosslinking agent. Taken together, our findings indicate that both plasticizer loss and H2S-SCV-induced crosslinking contribute significantly to the microstructural evolution of PAs when exposed to ethoxylated H2S-SCVs, offering important insights into their degradation mechanisms and long-term behavior in aggressive operational environments.<\/jats:p>","DOI":"10.3390\/polym17121634","type":"journal-article","created":{"date-parts":[[2025,6,12]],"date-time":"2025-06-12T07:44:23Z","timestamp":1749714263000},"page":"1634","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["New Insight into the Microstructure Changes and Molecular Mobility of Polyamides Exposed to H2S Scavengers"],"prefix":"10.3390","volume":"17","author":[{"ORCID":"https:\/\/orcid.org\/0009-0000-2852-4234","authenticated-orcid":false,"given":"Marina Perassoli de","family":"Lazari","sequence":"first","affiliation":[{"name":"Instituto de F\u00edsica de S\u00e3o Carlos, Universidade de S\u00e3o Paulo, 400 Parque Arnold Schimidt, S\u00e3o Carlos 13566-590, SP, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Antonio Henrique Monteiro da Fonseca Thom\u00e9 da","family":"Silva","sequence":"additional","affiliation":[{"name":"PETROBRAS\/CENPES, Av. Hor\u00e1cio Macedo 950, Rio de Janeiro 21941-915, RJ, Brazil"},{"name":"Departamento de Engenharia Mec\u00e2nica, Universidade Federal Fluminense\u2013UFF\/PGMEC, Niter\u00f3i 24210-240, RJ, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9953-9732","authenticated-orcid":false,"given":"Rodrigo Henrique dos Santos","family":"Garcia","sequence":"additional","affiliation":[{"name":"Instituto de F\u00edsica de S\u00e3o Carlos, Universidade de S\u00e3o Paulo, 400 Parque Arnold Schimidt, S\u00e3o Carlos 13566-590, SP, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sylvia Correa dos Santos","family":"Teixeira","sequence":"additional","affiliation":[{"name":"PETROBRAS\/CENPES, Av. Hor\u00e1cio Macedo 950, Rio de Janeiro 21941-915, RJ, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7461-5396","authenticated-orcid":false,"given":"Jo\u00e3o Eduardo de","family":"Oliveira","sequence":"additional","affiliation":[{"name":"Instituto de F\u00edsica de S\u00e3o Carlos, Universidade de S\u00e3o Paulo, 400 Parque Arnold Schimidt, S\u00e3o Carlos 13566-590, SP, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"\u00c9rica Gervasoni","family":"Chaves","sequence":"additional","affiliation":[{"name":"PETROBRAS\/CENPES, Av. Hor\u00e1cio Macedo 950, Rio de Janeiro 21941-915, RJ, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Luiz Ant\u00f4nio de Oliveira","family":"Nunes","sequence":"additional","affiliation":[{"name":"Instituto de F\u00edsica de S\u00e3o Carlos, Universidade de S\u00e3o Paulo, 400 Parque Arnold Schimidt, S\u00e3o Carlos 13566-590, SP, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Herc\u00edlio de Angeli","family":"Honorato","sequence":"additional","affiliation":[{"name":"PETROBRAS\/CENPES, Av. Hor\u00e1cio Macedo 950, Rio de Janeiro 21941-915, RJ, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sonia Maria Cabral de","family":"Menezes","sequence":"additional","affiliation":[{"name":"Instituto de F\u00edsica, Universidade de S\u00e3o Paulo, Rua do Mat\u00e3o 1371, Cidade Universit\u00e1ria, S\u00e3o Paulo 05508-090, SP, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Aline Pinde","family":"Lima","sequence":"additional","affiliation":[{"name":"PETROBRAS\/CENPES, Av. Hor\u00e1cio Macedo 950, Rio de Janeiro 21941-915, RJ, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0974-0465","authenticated-orcid":false,"given":"Luiz Silvino","family":"Chinelatto Junior","sequence":"additional","affiliation":[{"name":"PETROBRAS\/CENPES, Av. 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Electron."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"402","DOI":"10.1002\/(SICI)1521-3773(19980302)37:4<402::AID-ANIE402>3.0.CO;2-9","article-title":"Electroluminescent Conjugated Polymers\u2014Seeing Polymers in a New Light","volume":"37","author":"Kraft","year":"1998","journal-title":"Angew. Chem.-Int. Ed."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"401","DOI":"10.1016\/j.marstruc.2018.09.010","article-title":"Tension-bending analysis of flexible pipe by a repeated unit cell finite element model","volume":"64","author":"Lukassen","year":"2019","journal-title":"Mar. Struct."},{"key":"ref_4","unstructured":"Roseman, M., Martin, R., and Morgan, G. (2016). Marine Applications of Advanced Fibre-Reinforced Composites, Elsevier Inc."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1777","DOI":"10.1002\/app.30793","article-title":"Ageing of polyamide 11 used in the manufacture of flexible piping","volume":"114","author":"Castro","year":"2009","journal-title":"J. Appl. Polym. Sci."},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Khalid, H.U., Ismail, M.C., and Nosbi, N. (2020). Permeation Damage of Polymer Liner in Oil and Gas Pipelines: A Review. Polymers, 12.","DOI":"10.3390\/polym12102307"},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Perez-Pineiro, R., Cruz-Perez, D., Hoshowski, J., Zhang, H., and Hendry, J. (2018, January 15\u201319). H2S Scavenger Tower Operational Efficiency Achieved Through Onsite Compositional Analysis. Proceedings of the NACE\u2014International Corrosion Conference Series 2018, Phoenix, AZ, USA.","DOI":"10.5006\/C2018-11553"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"15936","DOI":"10.1021\/acs.iecr.1c02265","article-title":"Quantitative Analysis of Triazine-Based H2S Scavengers via Raman Spectroscopy","volume":"60","author":"Benhabib","year":"2021","journal-title":"Ind. Eng. Chem. Res."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"681","DOI":"10.1016\/j.fuel.2017.12.021","article-title":"Spectroscopic evaluation of commercial H2S scavengers","volume":"216","author":"Portela","year":"2018","journal-title":"Fuel"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"110001","DOI":"10.1016\/j.polymdegradstab.2022.110001","article-title":"1H Time Domain NMR to probe microstructural and mobility changes in Polyamide 11 exposed to H2S scavengers. What type of information can be assessed?","volume":"202","author":"Perez","year":"2022","journal-title":"Polym. Degrad. Stab."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"094902","DOI":"10.1063\/1.4977041","article-title":"Microscopic observation of the segmental orientation autocorrelation function for entangled and constrained polymer chains","volume":"146","author":"Mordvinkin","year":"2017","journal-title":"J. Chem. Phys."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"37","DOI":"10.1590\/S0104-14282012005000070","article-title":"Monitorando a Degrada\u00e7\u00e3o da Poliamida 11 (PA-11) via Espectroscopia na regi\u00e3o do Infravermelho m\u00e9dio com Transformada de Fourier (FTIR)","volume":"23","author":"Domingos","year":"2013","journal-title":"Polimeros"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"109851","DOI":"10.1016\/j.polymdegradstab.2022.109851","article-title":"Chemical coupling between oxidation and hydrolysis in polyamide 6\u2014A key aspect in the understanding of microplastic formation","volume":"197","author":"Deshoulles","year":"2022","journal-title":"Polym. Degrad. Stab."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"13","DOI":"10.3390\/chemistry6010002","article-title":"Pure Hydrolysis of Polyamides: A Comparative Study","volume":"6","author":"Brette","year":"2024","journal-title":"Chemistry"},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Zhang, R., Toshikazu, M., and Sun, P. (2019). NMR Methods for Characterization of Synthetic and Natural Polymers, Royal Society of Chemistry. [1st ed.].","DOI":"10.1039\/9781788016483"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"47","DOI":"10.1016\/j.jmr.2017.10.008","article-title":"Dipolar filtered magic-sandwich-echoes as a tool for probing molecular motions using time domain NMR","volume":"285","author":"Filgueiras","year":"2017","journal-title":"J. Magn. Reson."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.pnmrs.2007.01.001","article-title":"Proton multiple-quantum NMR for the study of chain dynamics and structural constraints in polymeric soft materials","volume":"51","year":"2007","journal-title":"Prog. Nucl. Magn. Reson. Spectrosc."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"899","DOI":"10.1021\/ma202030z","article-title":"Cross-link density estimation of PDMS networks with precise consideration of networks defects","volume":"45","author":"Lang","year":"2012","journal-title":"Macromolecules"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"3468","DOI":"10.1063\/1.1589000","article-title":"H 1 multiple-quantum nuclear magnetic resonance investigations of molecular order distributions in poly (dimethylsiloxane) networks: Evidence for a linear mixing law in bimodal systems","volume":"119","author":"Ziegler","year":"2003","journal-title":"J. Chem. Phys."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"065702","DOI":"10.1103\/PhysRevLett.108.065702","article-title":"Glass-transition temperature gradient in nanocomposites: Evidence from nuclear magnetic resonance and differential scanning calorimetry","volume":"108","author":"Papon","year":"2012","journal-title":"Phys. Rev. Lett."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"2015","DOI":"10.1063\/1.449344","article-title":"Multiple-quantum dynamics in solid state NMR","volume":"83","author":"Baum","year":"1985","journal-title":"J. Chem. Phys."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"65","DOI":"10.1255\/jnirs.236","article-title":"The assignment of overtone and combination bands in the near infrared spectrum of polyamide 11","volume":"7","author":"Wu","year":"1999","journal-title":"J. Near Infrared Spectrosc."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Wypych, G. (2023). Handbook of Plasticizers, Elsevier. [4th ed.].","DOI":"10.1016\/B978-1-77467-006-4.50006-0"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"2351","DOI":"10.1002\/(SICI)1099-0488(199610)34:14<2351::AID-POLB5>3.0.CO;2-Z","article-title":"Relaxation\u2013structure relationship in bulk and plasticized polyamide 11","volume":"34","author":"Serpe","year":"1996","journal-title":"J. Polym. Sci. B Polym. Phys."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"6617","DOI":"10.1016\/j.polymer.2007.08.058","article-title":"New solvent for polyamides and its application to the electrospinning of polyamides 11 and 12","volume":"48","author":"Behler","year":"2007","journal-title":"Polymer"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"289","DOI":"10.1016\/S0254-0584(98)00181-3","article-title":"Crystal phase transformations in nylon 11","volume":"56","author":"Hsin","year":"1998","journal-title":"Mater. Chem. Phys."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"161","DOI":"10.1016\/S0926-2040(96)01293-3","article-title":"Solid-state NMR characterization of copolymers of nylon 11 and nylon 12","volume":"8","author":"Johnson","year":"1997","journal-title":"Solid. State Nucl. Magn. Reson."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"103917","DOI":"10.1016\/j.apor.2024.103917","article-title":"Evaluation of aging process of PA11 from offshore flexible pipe pressure barrier","volume":"144","author":"Mota","year":"2024","journal-title":"Appl. Ocean Res."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"42792","DOI":"10.1002\/app.42792","article-title":"Aging of polyamide 11. Part 3: Multiscale model predicting the mechanical properties after hydrolytic degradation","volume":"132","author":"Mazan","year":"2015","journal-title":"J. Appl. Polym. Sci."},{"key":"ref_30","unstructured":"Celina, M.C. (2013). Polymer Degradation and Stability 2013, Elsevier."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1007\/s44245-024-00032-z","article-title":"The chemical impact of oil fluids in the morphology and thermal properties of the polyamide 11 used in flexible lines","volume":"3","author":"Dias","year":"2024","journal-title":"Discov. Mech. Eng."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"6249","DOI":"10.1002\/app.41971","article-title":"Aging of polyamide 11. Part 1: Evaluating degradation by thermal, mechanical, and viscometric analysis","volume":"132","author":"Mazan","year":"2015","journal-title":"Appl. Polym. Sci."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"49","DOI":"10.1016\/j.polymer.2015.11.025","article-title":"Investigation of polyamide 11 embrittlement during oxidative degradation","volume":"82","author":"Richaud","year":"2016","journal-title":"Polymer"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"123","DOI":"10.1016\/j.polymdegradstab.2014.05.028","article-title":"Molecular and macromolecular structure changes in polyamide 11 during thermal oxidation\u2013Kinetic modeling","volume":"108","author":"Richaud","year":"2014","journal-title":"Polym. Degrad. Stab."}],"container-title":["Polymers"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2073-4360\/17\/12\/1634\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T17:50:49Z","timestamp":1760032249000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2073-4360\/17\/12\/1634"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,6,12]]},"references-count":34,"journal-issue":{"issue":"12","published-online":{"date-parts":[[2025,6]]}},"alternative-id":["polym17121634"],"URL":"https:\/\/doi.org\/10.3390\/polym17121634","relation":{},"ISSN":["2073-4360"],"issn-type":[{"value":"2073-4360","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,6,12]]}}}