How Scientists Are Turning Old Tires Into Sustainable Hockey Pucks and More

Researchers at McMaster University have developed a chemical process to break down used tires and repurpose the rubber into new products. Partnering with Hyundai Canada, they are creating sustainable hockey pucks and exploring applications in asphalt, sealants, and insulation, reducing waste and carbon footprint.

English Transcript:

This may look like ashes or soot, but when I tell you it has the potential to completely revolutionize a major portion of waste on this planet, I'm not exaggerating because this material actually came from this. But it's been transformed in a mind-blowing way. And I'm about to explain why it's so significant. We all know that humans make a lot of waste, but most people don't think about how 1 billion tires end up as pure trash every single year. And while some are burned for fuel and recycling initiatives do exist, many are thrown into landfills where they not only take up a ton of space, but they also leech chemicals into the soil as they degrade and pose a serious fire

hazard because of how flammable they are and notoriously difficult to extinguish. But when you have brilliant minds discovering ways to transform this waste material into something usable, the implications are huge. So, my name is Mike Brooke and I've been at this university, McMaster University, for 40 years. Mike is one of the minds behind the initiative to transform tire waste material into something more. At McMaster University in Hamilton, Ontario, they actually partnered with Hyundai Canada, the car brand, who's also sponsoring this video, to try and turn tire waste into a sustainable hockey puck. A very Canadian endeavor. But in the process, the hope is to understand the materials more deeply for

even greater applications. Because even though this IonX 6 is fully electric, great for the environment, and extremely sleek, I might add, it still has rubber tires. So, let's go see what we can do with some old used ones. The problem is it's here's a piece of rubber. How do I get it into a form I can reuse it? It doesn't melt. It's an overdesigned product. Your greatgrandfather probably bought tires that might have lasted 10,000 mi, and now you're irritated if they don't last 100,000 miles. They are incredibly resilient, which is great when it's on your car, which is a nightmare when they're not on the car.

Mike and his colleagues actually made a major scientific breakthrough in 2020 on how to chemically break down tires, but preserve the rubber polymers to be used in new products. If your rubber tire is like a fishnet made of blue lines one way and red lines the other, they essentially created chemical scissors to selectively chop the red, preserving the blue rubber polymers, which could then be reused to make new rubbers. So when Hyundai proposed the idea of turning their tires into hockey pucks as part of their sustainable initiatives, they knew exactly who to go to. So one of the things is as a tire has metal under here, steel belt, and on the side it's got all kinds of plastic. So

we needed to break it down into smaller bits. The problem with simply trying to chop rubber down further in something like a grinder is that it has so much give and doesn't want to break apart and ultimately takes a ton of energy to blend down. So they started to get creative. It turns out if you can convert it from being a rubber into being a glass, now all of a sudden the process to break it up becomes much easier. If you imagine hitting this with a hammer, it'll bounce. But if it was glass and you hit it with a hammer, it shatters. So, how the heck are we going to make that glass? Once you cool them down sufficiently, they actually turn into a glass. So, we're going to do this experiment where we're going to cool it down using liquid

nitrogen. So, we'll just add this to that. And you can see it is bubbling like crazy. I think I'll put my gloves back on. I think that probably would be a sensible lab safety first. But you can see it's taking quite a long time. Not surprising. It's not hard to cool the outside, but it's like baking a cake. It never bakes from the inside out. It bakes from the outside in. And this is exactly the same thing now. It's pretty cold. Maybe not perfectly cold. I got to take it out and just like before, try and hit it with a hammer. So, we'll do that. Put it there. And is it brittle?

No, not completely because all of those fibers are holding it together. The team then took this principle further by completely freezing tire pieces and then instead of using a hammer, grinding it down in a blender, after which you end up with your tire crumb that you can now start doing really interesting environmentally useful things to this stuff is about 200 to 250 microns. And right now that's used for example to remediate asphalt. So bumen, that's the stuff that comes out of the ground costs a lot. So they're putting that into asphalt in California, for example, as a way of using the waste more effectively and not having to use as much bitchmen.

You get good performance, you save money, you're using waste, it's better for the environment. But Mike's team decided to explore a completely unique technique with the crumb that could turn this waste material into something even more useful. And they first got to test it with Hyundai's initiative to make a hockey puck. So what we decided to do is, okay, why don't we do this chemistry just on the surface of the crumb. So instead of dissolving all the rubber, we'll just dissolve the outer 10 microns. You know, a few hairs widths on the external part of the crumb and now make it like something else. And we've chosen to make it like silicones because that's that's what I do.

They decided to turn the waist crumb into a silicone. What's so special about silicone? Well, you almost certainly have come in contact with it in the last 24 hours. Whether you use a conditioner in your hair, deodorant or skin creams, or if you used your phone or other electronics, or simply sat on a toilet where the sealant is made of silicone to create a waterproof barrier, the stuff is all around us, and it's extremely useful. By combining silicone with the crumb, you're now left with a hybrid silicone that's partially made with the waste material that would otherwise be in a landfill. And this is huge because one of the challenges with silicone is that it has a very high carbon footprint

on its own. For every kilogram that's created, you need around 6 to 16 kg of CO2, which is a big number, much higher than plastics, for example. And while silicone application can often overcompensate for its high carbon cost, for example, when used on windows that help increase efficiency for heating and cooling, creating this new silicone crumb takes those numbers even further. The crumb that we're making has probably got 6. So that means you can use that to dilute a normal silicone. And we found the numbers are up to about 40%. The performance doesn't change very much.

It's still a silicone. It thinks it's a silicone. And yet the greenhouse gas footprint might have dropped by 30 20 30 40%. Because you're using waste. Here's the carbon footprint of the sealant by itself. Here's the carbon footprint of our stuff that we're putting in. If we put in 30%, we drop the net carbon footprint of the product. Mike and his colleagues actually started a company called Neopera to expand these silicone products using tire waste in all different percentages depending on the target application or product. But the hockey puck is where it all started. And hockey has been a big part of Hyundai Canada's social initiatives for over 15 years, which is why they've been

supporting this project for 4 years now, looking to make a difference when it comes to circular economy efforts. So in here there's like basically crumb that has been coated with the silicone plus a little bit of glue plus some glue. Plus it is a glue. So 80% of it is this modified crumb and the last 20% is what we call the secret sauce. And then when this comes out it'll be a solid puck. That's the plan. This formula was tested over and over again until perfected. Starting with tiny puck prototypes and tweaking the silicone solution or what they call the secret sauce to get a sufficient silicone coating around each piece of

tire chrome so that it aderes well to itself without any bald spots but also needing to get a final result that matches the standards of the NHL in shape, bounce, density, and resilience. And after letting the newest puck cure in the oven, we were finally left with our puck made with 80% used tires. There you have it folks, a green hockey puck. Of course, the puck then needed to go through multiple rounds of stress testing from drop tests to make sure it could hold together. They all survived. I mean, early pucks would not have survived this. They just crashed. Exactly. Like the hammer on the piece of rubber all the way to slap shots and sending it to other labs with cannon-like devices to see if it could hold up at the

highest speeds or if it would crumble under the pressure. Of course, as they perfect these techniques both for the hockey puck and other applications, they'll begin to scale up their capabilities. So, instead of using a coffee grinder and kitchen supplies, commercial blenders and mixers will be used to produce way more at once. But the essential ingredients are there now, which have the potential to make a big difference in many industries. Whether that be in roof coatings, external construction sealants, curtain walls, walkways made of recycled crumb, cement, or even things like heat and acoustic insulation in cars. Changes that are happening in the environment are a problem that we all share, right? Are we

going to solve it by flicking a switch and all the problems will go away? Of course not. A ground piece of rubber tire is not very valuable. Make it valuable again and maybe and again. And every time you do that, the original impact gets diluted. So we are not solving all the problems, but we're diminishing the magnitude. And that is what happens when you empower really smart people who care to make a difference. I want to send a huge thank you to Mike and his entire team at McMaster as well as Hyundai for sponsoring this video and making it all possible. One of the best parts of my job is getting to meet and learn from really smart people who care about the world and are trying to make a

difference. So, I feel super lucky to have been part of this. Thank you so much for watching. Make sure you like and subscribe and we'll see you ASAP for some more science. Peace.

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