{"id":5712,"date":"2023-09-13T17:46:00","date_gmt":"2023-09-13T17:46:00","guid":{"rendered":"https:\/\/new.www.purdue.edu\/newsroom\/?p=5712"},"modified":"2024-07-17T00:59:27","modified_gmt":"2024-07-17T00:59:27","slug":"solving-stickiness-sustainably","status":"publish","type":"post","link":"https:\/\/www.purdue.edu\/newsroom\/2023\/Q3\/solving-stickiness-sustainably","title":{"rendered":"Solving stickiness sustainably"},"content":{"rendered":"<div class=\"purdue-initial-words-wrap\"><p class=\"purdue-initial-words\">WEST LAFAYETTE, Ind. &mdash;<\/p> \n<p>Glue holds the world together.&nbsp;Without adhesives, much of modern human civilization \u2014&nbsp;including&nbsp;our cellphones, cars, furniture, walls and the packages arriving on our doorstep&nbsp;\u2014 would simply fall apart.<\/p>\n<\/div>\n\n\n<p>The trouble with all those adhesives is that they are not sustainable. A team of chemists at Purdue University led by\u00a0<a href=\"https:\/\/www.chem.purdue.edu\/people\/profile\/wilker\" target=\"_blank\" rel=\"noreferrer noopener\">Jonathan Wilker<\/a>, professor of chemistry in the College of Science and of materials engineering, aims to change that with a new, completely sustainable adhesive system. The team\u2019s findings were released in a paper in\u00a0<a href=\"https:\/\/www.nature.com\/articles\/s41586-023-06335-7\" target=\"_blank\" rel=\"noreferrer noopener\">Nature<\/a>.\u00a0<\/p>\n\n\n\n    <div  class=\"purdue-home-quick-links-static \">\n        <div class=\"tagged-header-container\">\n\n            <h2 class=\"tagged-header\"><span>Additional Information<\/span><\/h2>\n        \n        <\/div>\n\n       <ul class=\"quick-links-content\">\n                                        <li class=\"quick-link__item\">\n                                                                <a class=\"quick-link__link\"\n                                    href=\"https:\/\/www.purdue.edu\/research\/features\/stories\/shellfish-inspire-chemists-to-develop-new-stronger-more-sustainable-glues\/\" target=\"_blank\">\n                                    Shellfish inspire chemists to develop new, stronger, more sustainable glues                                <\/a>\n                            <\/li>\n                                                <li class=\"quick-link__item\">\n                                                                <a class=\"quick-link__link\"\n                                    href=\"https:\/\/www.purdue.edu\/newsroom\/releases\/2022\/Q2\/environmentally-sustainable-commercial-adhesive-from-purdue-is-optioned-to-glueco-adhesives.html\" target=\"_blank\">\n                                    Environmentally sustainable commercial adhesive from Purdue is optioned to gluECO Adhesives                                <\/a>\n                            <\/li>\n                                                <li class=\"quick-link__item\">\n                                                                <a class=\"quick-link__link\"\n                                    href=\"https:\/\/www.purdue.edu\/newsroom\/releases\/2020\/Q3\/changing-seawater-hints-at-future-for-adhesives-from-sea-creatures.html\" target=\"_blank\">\n                                    Changing seawater hints at future for adhesives from sea creatures                                <\/a>\n                            <\/li>\n                            <\/ul>\n\n<\/div>\n\n\n\n\n<p>\u201cOur current adhesives create all sorts of environmental problems,\u201d Wilker said. \u201cAlmost all glues are petroleum-based and do not degrade. The bonded materials in our products stay stuck together. Consequently, we cannot recycle many of the materials that we put into our recycling bins. Discarded products will sit in landfills for centuries and, sometimes, contribute to ocean microplastics.\u201d<\/p>\n\n\n\n<p>Wilker and his lab have spent years studying the science of sticky substances, analyzing marine animals that adhere, like mussels and oysters, and trying to create better, sustainable, affordable adhesives that work as well as any glue from the hardware store. He has a drawer of those commercial glues in his lab, which give off a strong and familiar smell.&nbsp;<\/p>\n\n\n\n<p>\u201cThose volatile petrochemicals in these glues can be toxic, which is a further problem with current technologies,\u201d Wilker said. One example is the common building material plywood, which is formed of wood pieces held together with formaldehyde-based adhesives. Newly built houses are off-gassing formaldehyde, exposing residents to this carcinogen.<\/p>\n\n\n\n<p>These substances are harmful both to the environment and to human health. However, people and companies are accustomed to using traditional adhesives; they\u2019re strong, easy to produce and relatively inexpensive. Any new adhesive must work at least as well as traditional products, which is why Wilker keeps that drawer around: to test them, side by side, against innovative substances.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"800\" height=\"450\" src=\"https:\/\/new.www.purdue.edu\/newsroom\/wp-content\/uploads\/2024\/07\/wilker-soyoilLO.jpg\" alt=\"Soybean field\" class=\"wp-image-5715\" title=\"\" srcset=\"https:\/\/www.purdue.edu\/newsroom\/wp-content\/uploads\/2024\/07\/wilker-soyoilLO.jpg 800w, https:\/\/www.purdue.edu\/newsroom\/wp-content\/uploads\/2024\/07\/wilker-soyoilLO-300x169.jpg 300w, https:\/\/www.purdue.edu\/newsroom\/wp-content\/uploads\/2024\/07\/wilker-soyoilLO-768x432.jpg 768w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><figcaption class=\"wp-element-caption\">One of the main ingredients of Wilker\u2019s sustainable adhesive is epoxidized soy oil, a substance already produced and used on an enormous scale throughout the world. One simple and usually easy and inexpensive step turns raw soybean oil into epoxidized soybean oil, making it an affordable, accessible and effective ingredient in sustainable adhesives. (Photo by Adobe Stock)<\/figcaption><\/figure>\n\n\n\n<p>\u201cBy studying how nature makes adhesives, we are learning how to design new technologies for our future society,\u201d Wilker said. \u201cGiven all of the problems generated by current glues, we feel an obligation to create something better. Ideally, new adhesives will be bio-based and nontoxic. Strengths should be as high as current products. Then we would like to bond them strongly when needed and also be able to take the substrates apart when wanted. Further design constraints that we grapple with, in order to have impact, are costs needing to be low and having all starting compounds available at large scales.\u201d<\/p>\n\n\n\n<p>After a series of experiments on a range of different biologically sourced and sustainable ingredients, the team settled on epoxidized soy oil for a main component. Epoxidized soy oil is already produced globally on a massive scale. For their work, the smallest container that they could purchase was a 55-gallon drum of the substance. Since each experiment uses just a little epoxidized soy oil, the level in their drum has dropped only a few inches after several years of testing.<\/p>\n\n\n\n<p>Wilker and his team added the epoxidized soy oil to malic acid, a compound most known for giving apples their tart flavor. Then they added tannic acid, to provide an aspect of the chemistry that mussels use for attaching themselves to rocks and each other. Tannic acid is a component of tannins, common in trees, red wine and black tea. Those three ingredients added up to an adhesive that is inexpensive, effective, scalable, practical to produce and completely sustainable. &nbsp;<\/p>\n\n\n\n<p>\u201cIf you combine these components under the right conditions, adhesives can be made that are as strong as epoxies,\u201d Wilker said. Epoxies are generally considered to be the highest performance class of adhesives. \u201cAll of the components are bio-based, safe and already available at train car scales. A bonus is that the adhesive is easy to make. Basically, you can mix and heat the components.\u201d Other bio-based compounds can also be used with epoxidized soy oil, generating an entire family of new sustainable adhesives.<\/p>\n\n\n\n<p>To test the adhesive\u2019s performance, the scientists bonded together objects \u2014 wood, plastics or metals \u2014 and then used an instrument for breaking the bonds and measuring forces. In many cases, their new adhesives held up well, sometimes performing similarly to, or even better than, traditional toxic adhesives such as a superglue and an epoxy. Further research will refine the system and work to maximize societal and environmental impacts in areas ranging from medical innovations to industrial materials to packaging. Their team\u2019s innovations may pave the way to a more sustainable system for holding the world together.<\/p>\n\n\n\n<p>Wilker&nbsp;disclosed his adhesives to the Purdue Innovates Office of Technology Commercialization, which has applied for a patent to protect the intellectual property. This research was supported by the Office of Naval Research.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">About Purdue University<\/h2>\n\n\n\n<p>Purdue University is a public research institution with excellence at scale. Ranked among the top 10 public universities and with two colleges in the top 4 in the United States, Purdue discovers and disseminates knowledge with a quality and at a scale second to none. More than 105,000 students study at Purdue across modalities and locations, with 50,000 in person on the West Lafayette campus. Committed to affordability and accessibility, Purdue\u2019s main campus has frozen tuition 12 years in a row. See how Purdue never stops in the persistent pursuit of the next giant leap, including its first comprehensive urban campus in Indianapolis, the new Mitchell E. Daniels, Jr. School of Business, and Purdue Computes, at&nbsp;<a href=\"https:\/\/www.purdue.edu\/president\/strategic-initiatives\" rel=\"noreferrer noopener\" target=\"_blank\">https:\/\/www.purdue.edu\/president\/strategic-initiatives<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>WEST LAFAYETTE, Ind. &mdash; Glue holds the world together.&nbsp;Without adhesives, much of modern human civilization \u2014&nbsp;including&nbsp;our cellphones, cars, furniture, walls and the packages arriving on our doorstep&nbsp;\u2014 would simply fall apart. The trouble with all those adhesives is that they<\/p>\n","protected":false},"author":7,"featured_media":5714,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[7],"tags":[],"department":[31,32],"source":[29],"purdue_today_topic":[],"coauthors":[77],"class_list":["post-5712","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-research-excellence","department-engineering","department-science","source-purdue-news"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.purdue.edu\/newsroom\/wp-json\/wp\/v2\/posts\/5712","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.purdue.edu\/newsroom\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.purdue.edu\/newsroom\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.purdue.edu\/newsroom\/wp-json\/wp\/v2\/users\/7"}],"replies":[{"embeddable":true,"href":"https:\/\/www.purdue.edu\/newsroom\/wp-json\/wp\/v2\/comments?post=5712"}],"version-history":[{"count":8,"href":"https:\/\/www.purdue.edu\/newsroom\/wp-json\/wp\/v2\/posts\/5712\/revisions"}],"predecessor-version":[{"id":5828,"href":"https:\/\/www.purdue.edu\/newsroom\/wp-json\/wp\/v2\/posts\/5712\/revisions\/5828"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.purdue.edu\/newsroom\/wp-json\/wp\/v2\/media\/5714"}],"wp:attachment":[{"href":"https:\/\/www.purdue.edu\/newsroom\/wp-json\/wp\/v2\/media?parent=5712"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.purdue.edu\/newsroom\/wp-json\/wp\/v2\/categories?post=5712"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.purdue.edu\/newsroom\/wp-json\/wp\/v2\/tags?post=5712"},{"taxonomy":"department","embeddable":true,"href":"https:\/\/www.purdue.edu\/newsroom\/wp-json\/wp\/v2\/department?post=5712"},{"taxonomy":"source","embeddable":true,"href":"https:\/\/www.purdue.edu\/newsroom\/wp-json\/wp\/v2\/source?post=5712"},{"taxonomy":"purdue_today_topic","embeddable":true,"href":"https:\/\/www.purdue.edu\/newsroom\/wp-json\/wp\/v2\/purdue_today_topic?post=5712"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/www.purdue.edu\/newsroom\/wp-json\/wp\/v2\/coauthors?post=5712"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}