{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,21]],"date-time":"2026-09-21T20:48:41Z","timestamp":1790023721486,"version":"4.0.1"},"reference-count":44,"publisher":"MDPI AG","issue":"24","license":[{"start":{"date-parts":[[2024,12,18]],"date-time":"2024-12-18T00:00:00Z","timestamp":1734480000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100009620","name":"Science and Technology Department of Gansu Province","doi-asserted-by":"publisher","award":["24YFGA042"],"award-info":[{"award-number":["24YFGA042"]}],"id":[{"id":"10.13039\/501100009620","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100009620","name":"Science and Technology Department of Gansu Province","doi-asserted-by":"publisher","award":["2023-QN-19"],"award-info":[{"award-number":["2023-QN-19"]}],"id":[{"id":"10.13039\/501100009620","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100009620","name":"Science and Technology Department of Gansu Province","doi-asserted-by":"publisher","award":["JK2024-33"],"award-info":[{"award-number":["JK2024-33"]}],"id":[{"id":"10.13039\/501100009620","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100007764","name":"Lanzhou Science and Technology Bureau","doi-asserted-by":"publisher","award":["24YFGA042"],"award-info":[{"award-number":["24YFGA042"]}],"id":[{"id":"10.13039\/501100007764","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100007764","name":"Lanzhou Science and Technology Bureau","doi-asserted-by":"publisher","award":["2023-QN-19"],"award-info":[{"award-number":["2023-QN-19"]}],"id":[{"id":"10.13039\/501100007764","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100007764","name":"Lanzhou Science and Technology Bureau","doi-asserted-by":"publisher","award":["JK2024-33"],"award-info":[{"award-number":["JK2024-33"]}],"id":[{"id":"10.13039\/501100007764","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Department of Housing and Urban-Rural Development of Gansu Province","award":["24YFGA042"],"award-info":[{"award-number":["24YFGA042"]}]},{"name":"Department of Housing and Urban-Rural Development of Gansu Province","award":["2023-QN-19"],"award-info":[{"award-number":["2023-QN-19"]}]},{"name":"Department of Housing and Urban-Rural Development of Gansu Province","award":["JK2024-33"],"award-info":[{"award-number":["JK2024-33"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Polymers"],"abstract":"<jats:p>This study investigates the effect of microstructural changes in polyurethane coatings on their water resistance properties. Polyurethane coatings with varying diluent contents were prepared and tested for water penetration resistance and mechanical property retention. The time-dependent behavior of water within the coatings at different immersion durations was analyzed using low-field nuclear magnetic resonance (NMR). Furthermore, the free volume and characteristic molecular groups of each coating were analyzed using microscopic techniques, including positron annihilation lifetime spectroscopy (PALS) and attenuated total reflectance Fourier-transform infrared spectroscopy (ATR\u2212FTIR). Results indicate that diluent content significantly alters the microstructure of the coatings. With increasing diluent content, both the average pore volume and free volume fraction initially decrease and then increase, while characteristic molecular groups, including hydrophilic groups, gradually decline. The water resistance performance of the coatings was significantly influenced by the combined effects of free volume and characteristic molecular groups. Among the five tested coating formulations, coatings with diluent contents of 20% and 25% showed a superior water penetration resistance, higher retention of mechanical properties after immersion, and relatively low total content of bound and free water at all immersion ages. The entropy weight method and the equal weight method were used to assess the overall water resistance, with the following ranking of scores: f20 &gt; f25 &gt; f30 &gt; f15 &gt; f10. This study offers theoretical support to guide the design and practical application of polyurethane coatings in real-world engineering projects.<\/jats:p>","DOI":"10.3390\/polym16243529","type":"journal-article","created":{"date-parts":[[2024,12,18]],"date-time":"2024-12-18T11:17:22Z","timestamp":1734520642000},"page":"3529","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["Study of Water Resistance of Polyurethane Coatings Based on Microanalytical Methods"],"prefix":"10.3390","volume":"16","author":[{"given":"Chao","family":"Xie","sequence":"first","affiliation":[{"name":"Civil Engineering Department, Lanzhou Jiaotong University, Lanzhou 730070, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yufeng","family":"Shi","sequence":"additional","affiliation":[{"name":"Civil Engineering Department, Lanzhou Jiaotong University, Lanzhou 730070, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zhuozhuo","family":"Si","sequence":"additional","affiliation":[{"name":"Civil Engineering Department, Lanzhou Jiaotong University, Lanzhou 730070, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ping","family":"Wu","sequence":"additional","affiliation":[{"name":"CSCEC AECOM Consultants Co., Ltd., Lanzhou 730000, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Binqiang","family":"Sun","sequence":"additional","affiliation":[{"name":"Gansu Yi\u2019an Construction Technology Group Co., Ltd., Lanzhou 730060, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Wenzhe","family":"Ma","sequence":"additional","affiliation":[{"name":"Civil Engineering Department, Lanzhou Jiaotong University, Lanzhou 730070, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2024,12,18]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"114","DOI":"10.1016\/j.engfailanal.2014.02.004","article-title":"Cement and concrete as an engineering material: An historic appraisal and case study analysis","volume":"40","author":"Gagg","year":"2014","journal-title":"Eng. 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