{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,29]],"date-time":"2026-06-29T15:47:07Z","timestamp":1782748027077,"version":"3.54.5"},"reference-count":31,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2021,3,18]],"date-time":"2021-03-18T00:00:00Z","timestamp":1616025600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Toxics Use Reduction Institute","award":["Academic Research Grants"],"award-info":[{"award-number":["Academic Research Grants"]}]},{"name":"University of Massachusetts Lowell","award":["Start-up funds"],"award-info":[{"award-number":["Start-up funds"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Polymers"],"abstract":"<jats:p>Conformal coating is typically composed of polymeric film and is used to protect delicate electronic components such as printed-circuit boards. Without removing conformal coating, it would be difficult to repair these complicated electronics. Methylene chloride, also called dichloromethane (DCM), has a widespread usage in conformal coating stripper products. The high toxicity of DCM increases human health risk when workers are exposed to DCM during the conformal coating removal processes. Therefore, the replacement of DCM would be beneficial to greatly improve the overall safety profile for workers in the electronics and coating industries. This research identified and evaluated alternative chemicals for replacing DCM used in acrylic conformal coating stripping operations. The solubility of an acrylic conformal coating was measured and characterized using Hansen solubility parameters (HSP) theory. Coating dwell time tests using various solvent blends verified the accuracy of the created HSP solubility sphere. A data processing method was also developed to identify and screen potential alternative solvent blends in terms of safety, toxicity, and cost-effectiveness. The identified safer solvent blends were demonstrated to provide equivalent stripping performance as compared to DCM based coating strippers within an acceptable cost range. The results of this research will be of value to other types of conformal coatings, such as silicone and polyurethane, where DCM is commonly used in similar coating stripping operations. By safely removing conformal coating, delicate electronics would be available for re-manufacturing, enabling a circular economy.<\/jats:p>","DOI":"10.3390\/polym13060937","type":"journal-article","created":{"date-parts":[[2021,3,18]],"date-time":"2021-03-18T22:19:36Z","timestamp":1616105976000},"page":"937","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":15,"title":["Removing Acrylic Conformal Coating with Safer Solvents for Re-Manufacturing Electronics"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7530-002X","authenticated-orcid":false,"given":"Taofeng","family":"Lu","sequence":"first","affiliation":[{"name":"Department of Plastics Engineering, Francis College of Engineering, University of Massachusetts Lowell, Lowell, MA 01854, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gregory","family":"Reimonn","sequence":"additional","affiliation":[{"name":"Department of Plastics Engineering, Francis College of Engineering, University of Massachusetts Lowell, Lowell, MA 01854, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gregory","family":"Morose","sequence":"additional","affiliation":[{"name":"Toxics Use Reduction Institute, University of Massachusetts Lowell, Lowell, MA 01852, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8266-9821","authenticated-orcid":false,"given":"Evan","family":"Yu","sequence":"additional","affiliation":[{"name":"Department of Plastics Engineering, Francis College of Engineering, University of Massachusetts Lowell, Lowell, MA 01854, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2294-1461","authenticated-orcid":false,"given":"Wan-Ting","family":"Chen","sequence":"additional","affiliation":[{"name":"Department of Plastics Engineering, Francis College of Engineering, University of Massachusetts Lowell, Lowell, MA 01854, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2021,3,18]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"217","DOI":"10.1109\/TEPM.2006.882496","article-title":"Surface Insulation Resistance of Conformally Coated Printed Circuit Boards Processed with No-Clean Flux","volume":"29","author":"Zhan","year":"2006","journal-title":"IEEE Trans. Electron. Packag. Manuf."},{"key":"ref_2","unstructured":"Morose, G., Marshall, J., McCarthy, A., Harripersaud, V., and Giarrosso, A. (2020). Assessment of Safer and Effective Alternatives for Coating Removal Products, Toxics Use Reduction Institute."},{"key":"ref_3","unstructured":"(2020, June 16). Conformal Coatings Market Size & Share. Available online: https:\/\/www.grandviewresearch.com\/industry-analysis\/conformal-coating-market."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Dobriyal, P., Ramalingam, S., Lim, S.L., and Kurella, A. (2016, January 25\u201328). Conformal coating challenges: Detection, rework and failure analysis. Proceedings of the 2016 Pan Pacific Microelectronics Symposium (Pan Pacific), Big Island, HI, USA.","DOI":"10.1109\/PanPacific.2016.7428411"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"703","DOI":"10.1289\/ehp.1509730","article-title":"Human Health Effects of Biphenyl: Key Findings and Scientific Issues","volume":"124","author":"Li","year":"2016","journal-title":"Environ. Health Perspect."},{"key":"ref_6","unstructured":"USEPA (2017). Scope of the Risk Evaluation for Methylene Chloride."},{"key":"ref_7","unstructured":"World Health Organization (2000). Air Quality Guidelines for Europe, WHO Regional Office for Europe."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"9","DOI":"10.1186\/1476-069X-2-9","article-title":"Source reduction for prevention of methylene chloride hazards: Cases from four industrial sectors","volume":"2","author":"Roelofs","year":"2003","journal-title":"Environ. Health"},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Cseri, L., Razali, M., Pogany, P., and Szekely, G. (2018). Organic Solvents in Sustainable Synthesis and Engineering. Green Chemistry, Elsevier.","DOI":"10.1016\/B978-0-12-809270-5.00020-0"},{"key":"ref_10","unstructured":"(2021, March 08). Paint and Varnish Strippers. Available online: https:\/\/saferchemicals.org\/wp-content\/uploads\/2019\/12\/paint_strippers_safer_alternatives_december_2019-updated.pdf."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Taygerly, J.P., Miller, L.M., Yee, A., and Peterson, E.A. (2012). A convenient guide to help select replacement solvents for dichloromethane in chromatography. Green Chem., 14.","DOI":"10.1039\/c2gc36064k"},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Jhamb, S., Liang, X., Dam-Johansen, K., and Kontogeorgis, G.M. (2020). A model-based solvent selection and design framework for organic coating formulations. Prog. Org. Coatings, 140.","DOI":"10.1016\/j.porgcoat.2019.105471"},{"key":"ref_13","unstructured":"Giarrosso, A. (2019). Investigating the Effective Removal of Gel Nail Polish with the Hansen Solubility Parameters, University of Massachusetts."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"2425","DOI":"10.1021\/es5055786","article-title":"Method for efficient recovery of high-purity polycarbonates from electronic waste","volume":"49","author":"Weeden","year":"2015","journal-title":"Environ. Sci. Technol."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1800069","DOI":"10.1002\/adts.201800069","article-title":"A Bayesian Approach to Predict Solubility Parameters","volume":"2","author":"Roch","year":"2019","journal-title":"Adv. Theory Simul."},{"key":"ref_16","unstructured":"Abbott, S., Hansen, C.M., and Yamamoto, H. (2020, January 14). Hansen Solubility Parameters in Practice\u2014Complete with eBook, Software and Data. Available online: www.hansen-solubility.com."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1053","DOI":"10.1007\/s00289-011-0607-8","article-title":"A new procedure for calculating Hansen solubility parameters of carbon nanotube\/polymer composites","volume":"68","author":"Ma","year":"2012","journal-title":"Polymer Bull."},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"D\u00edaz de los R\u00edos, M., and Hern\u00e1ndez Ramos, E. (2020). Determination of the Hansen solubility parameters and the Hansen sphere radius with the aid of the solver add-in of Microsoft Excel. SN Appl. Sci., 2.","DOI":"10.1007\/s42452-020-2512-y"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"441","DOI":"10.1111\/jphp.12948","article-title":"Application of the solubility parameter concept to assist with oral delivery of poorly water-soluble drugs\u2014A PEARRL review","volume":"71","author":"Jankovic","year":"2019","journal-title":"J. Pharm. Pharmacol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"7","DOI":"10.1016\/j.supflu.2005.11.008","article-title":"Are solubility parameters relevant to supercritical fluids?","volume":"38","author":"Marcus","year":"2006","journal-title":"J. Supercrit. Fluids"},{"key":"ref_21","unstructured":"(2020, June 18). Hazard Assessments. Available online: https:\/\/pharosproject.net\/."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"717","DOI":"10.1557\/PROC-121-717","article-title":"Physics and Applications of DIP Coating and Spin Coating","volume":"121","author":"Scriven","year":"1988","journal-title":"MRS Proc."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"120","DOI":"10.1016\/j.memsci.2017.10.016","article-title":"Shortcut applications of the Hansen Solubility Parameter for Organic Solvent Nanofiltration","volume":"546","author":"Darvishmanesh","year":"2018","journal-title":"J. Membr. Sci."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"12274","DOI":"10.1002\/anie.201503476","article-title":"London dispersion in molecular chemistry--reconsidering steric effects","volume":"54","author":"Wagner","year":"2015","journal-title":"Angew. Chem. Int. Ed. Engl."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"114","DOI":"10.1021\/acs.oprd.6b00401","article-title":"Methodology for Replacing Dipolar Aprotic Solvents Used in API Processing with Safe Hydrogen-Bond Donor and Acceptor Solvent-Pair Mixtures","volume":"21","author":"Duereh","year":"2017","journal-title":"Org. Process. Res. Dev."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"242","DOI":"10.1002\/ieam.1605","article-title":"Chemical assessment state of the science: Evaluation of 32 decision-support tools used to screen and prioritize chemicals","volume":"11","author":"Gauthier","year":"2015","journal-title":"Integr. Environ. Assess. Manag."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"3879","DOI":"10.1039\/C6GC00611F","article-title":"Updating and further expanding GSK\u2019s solvent sustainability guide","volume":"18","author":"Alder","year":"2016","journal-title":"Green Chem."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"13","DOI":"10.1108\/030561201998000002","article-title":"Conformal coating removal techniques","volume":"24","author":"Horrocks","year":"1998","journal-title":"Circuit World"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"747","DOI":"10.1021\/acs.chemrev.7b00571","article-title":"Green and Sustainable Solvents in Chemical Processes","volume":"118","author":"Clarke","year":"2018","journal-title":"Chem. Rev."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"10","DOI":"10.1016\/j.chroma.2015.10.083","article-title":"Tailoring and recycling of deep eutectic solvents as sustainable and efficient extraction media","volume":"1424","author":"Jeong","year":"2015","journal-title":"J. Chromatogr. A"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"18444","DOI":"10.1021\/acssuschemeng.9b04245","article-title":"Process Intensification via Continuous and Simultaneous Isolation of Antioxidants: An Upcycling Approach for Olive Leaf Waste","volume":"7","author":"Voros","year":"2019","journal-title":"ACS Sustain. Chem. 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