{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,3]],"date-time":"2026-10-03T04:13:38Z","timestamp":1791000818417,"version":"4.1.0"},"reference-count":57,"publisher":"MDPI AG","issue":"18","license":[{"start":{"date-parts":[[2024,9,10]],"date-time":"2024-09-10T00:00:00Z","timestamp":1725926400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Khansaheb Industries"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Polymers"],"abstract":"<jats:p>In this work, a new class of fourth-generation, zero ozone depletion potential, hydrofluoroolefin-based blowing agents were used to prepare phenolic foam. While hydrofluoroolefin blowing agents have been used previously to prepare polyurethane foams, few studies have been reported on their use in phenolic foams. We introduce an effective method for foam preparation using two low-boiling blowing agents, cis-1,1,1,4,4,4-hexafluoro-2-butene and trans-1,1,1,4,4,4-hexafluoro-2-butene, and their combinations with hexane. Traditionally, phenolic foams have been prepared using chlorofluorocarbons and hydrochlorofluorocarbons, which can have harmful effects on the environment due to their high ozone depletion potential or global warming potential. Conductor-like screening model for real solvents (COSMO-RS) modeling studies were performed to understand the effects of different blowing agent combinations on their boiling points. A series of phenolic foams were prepared by varying the concentration of the hydrofluoroolefin and the hydrofluoroolefin\u2013hexane blowing agent combinations. The concentrations of the surfactant, Agnique CSO 30, and the toughening agent, polyethylene glycol, were also varied to yield a formulation with the optimal properties. The foams formulated with the hydrofluoroolefin\u2013hexane mixture displayed a higher compressive strength and a lower thermal conductivity than those prepared with either hydrofluoroolefin or hexane alone. The cell microstructure of all the foams was examined using scanning electron microscopy. By introducing flexible chains into the resin matrix, PEG facilitates proper distribution of hydrofluoroolefin\u2013hexane blowing agents and other reagents and thereby increases the mechanical strength of the foam.<\/jats:p>","DOI":"10.3390\/polym16182558","type":"journal-article","created":{"date-parts":[[2024,9,10]],"date-time":"2024-09-10T07:33:25Z","timestamp":1725953605000},"page":"2558","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":9,"title":["Phenolic Foam Preparation Using Hydrofluoroolefin Blowing Agents and the Toughening Effect of Polyethylene Glycol"],"prefix":"10.3390","volume":"16","author":[{"given":"P. R.","family":"Sarika","sequence":"first","affiliation":[{"name":"Department of Chemical & Biological Engineering, American University of Sharjah, Sharjah P.O. Box 26666, United Arab Emirates"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6188-8491","authenticated-orcid":false,"given":"Paul","family":"Nancarrow","sequence":"additional","affiliation":[{"name":"Department of Chemical & Biological Engineering, American University of Sharjah, Sharjah P.O. Box 26666, United Arab Emirates"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4233-1962","authenticated-orcid":false,"given":"Taleb H.","family":"Ibrahim","sequence":"additional","affiliation":[{"name":"Department of Chemical & Biological Engineering, American University of Sharjah, Sharjah P.O. Box 26666, United Arab Emirates"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2024,9,10]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"988","DOI":"10.1016\/j.rser.2016.05.045","article-title":"Insulation Materials for the Building Sector: A Review and Comparative Analysis","volume":"62","author":"Schiavoni","year":"2016","journal-title":"Renew. Sustain. Energy Rev."},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Pfundstein, M., Gellert, R., Spitzner, M., and Rudolphi, A. (2008). Insulating Materials: Principles, Materials, Applications, Birkh\u00e4user.","DOI":"10.11129\/detail.9783034614757"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1002\/app.39942","article-title":"Phenolic Foams Modified by Cardanol through Bisphenol Modification","volume":"131","author":"Jing","year":"2014","journal-title":"J. Appl. Polym. 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