Think about a class of materials you use in all kinds of ways, every single day. You drink from it, wear it, and rely on it to keep you safe. It's hard to imagine a world without polymers. From takeout containers, to pipes, utensils and appliances, to a human spine you can create on a 3D printer.

Polymers appear just about everywhere. In fact, it's hard to imagine what we can't do with this incredibly versatile material.
>> Polymers are molecules which are around us everywhere in our life. They are the plastic bags, they're disposable water bottles, that we encounter. They're in advanced materials such as automobile parts and medical equipment as well, so plastics and other types of polymers are everywhere.

So what we have here is a lumbar spine segment from an actual patient. We CT'ed the patient, and then through a treatment planning software system, we were able to contour all of the vertebrae, the sacrum, and the disks in between. What this is going to be used for is, we do virtual reality simulators for the medical students here.

We could bend the spine, as you can see here. And that gives the medical students the capability of flexing the model.
>> I have a choice of three different materials that are loaded into the machine. Flexible one, and an ABS like one, and a hard clear one. I could also have the option of mixing some.

So, for instance right here I've got a hard clear and a flexible and I can choose different percentages of each one.
>> This is a 3D printed lens that I designed on the computer. And we had printed here right in this room. Printing the lenses on the 3D printer allows you to make complex lenses very easily and very cheap, whereas if you make a complex lens it might cost you more.

But you can just whip this up on the computer in five minutes and have it printed and have it in your hands the next day for polishing. This lens will be part of a system that allows us to see wide angle views, kind of like fish eye lenses.

But our goal is to make fish eye much more resolute and get higher definition images on the wider angles, and that can be used in astronomy, or even just recreational use. But it gives you a stronger resolution on the edges of the camera.
>> Despite the amazingly intricate things we can do now with polymers, society's perceptions of them are almost as complex.


>> We think of plastic on one side it's fake, it's articifical, gaudy, cheap. But, plastic also means you can transform it, it means versatility. If you made that a Facebook status, you'd say it's complicated. It's got really positive and negative meanings.
>> The word polymer comes from Greek, where poly means many and mer means unit.

A polymer is a chain of many small molecules that are all joined together. Polymers can be natural like silk or cotton, or synthetic, like nylon, polyester, and moisture-wicking fabrics in athletic clothing. Take Nina's helmet, no athlete likes to be weighed down. So the trick is to make protective gear that's lightweight but tough enough to cushion impact.

But the perception they last forever isn't exactly true. While they can last a long time, polymers do eventually degrade. Which means safety gear like this needs to be replaced periodically. When we talk about polymers, we often think about them piling up in landfills and never breaking down. But there is another sustainability concern that you might not be aware of and that's where polymers come from.


>> These polymers are usually derived from petroleum sources. So, crude oil is recovered from the ground, and that oil is then converted to polymers and plastics. In our lab, we're looking for another alternative to petroleum. We're looking at renewable resources, which can be regenerated on an annual basis, and have very limited environmental impact.

There are many options which are being commercialized by companies and being developed in labs as well. Things such vegetable oils and their fatty acids, and they can be oils such as soy bean oil, which is very common in the United Sates. Caster oil, palm oil, palm kernel oil, linseed oil, all of these are similar in that they have what's known as a triglyceride structure.

Which means, every molecule has three fatty acids. A related type of oil are, oils which are actually produced by algae. And these algae oils actually have very similar characteristics to the vegetable oils. The advantage of the algae oils is that they can actually be produced in waste water.

Therefore, you no longer have a competition with food sources for chemicals and plastics. There are even micro-organisms which creates certain types of polymers for energy sources. And so any and all of these sources are of interest to replace the conventional plastics and polymers that we've become so dependent on a society.

This is polylactide, it's a polymer and is derived from corn sugars. This is also polylactide, but we've modified it with a vegetable oil. The modified material Has superior mechanical properties such as increased toughness, which we measure with tensile testing. Here we're showing you a tensile tester in our laboratory which is used to examine the mechanical behavior of polymers and plastics.

In the tensile testing experiment, a specimen of the sample is placed between two grips. The tester then pulls on the sample, until the sample breaks. We measure the force and we also measure the change in the sample length, before it breaks. What we're looking at here is a sample polylactide, which is a very brittle polymer.

And you can see that it breaks very quickly. It takes very little change in length in order for the polymer to fracture. In contrast, we have polylactide, which we've modified with vegetable oils. This modified polylactide can undergo a significantly higher elongation before it breaks and therefore it's a significantly tougher material than the neat version of the polymer.

This material is called the thermoplastic elastomer. It's derived from vegetable oils, like soybean oil and palm kernel oil. A thermoplastic elastomer is a very unique material. It behaves like an elastomer, or a rubber you might be familiar with a rubber band a rubber tire, in that it's stretchy and can elongate.

And if you release the force and release the stress it will go back to its original configuration and shape. However what makes this material different from other elastomers and rubbers, is that it also has characteristics of a thermoplastic. A thermoplastic is a material that if once heated, will change its shape and can be reformed and reprocessed into a new shape.

For example, water bottles are thermoplastics. Styrofoam is made for a thermoplastic. Thermal plastic elastomers are used on a variety of applications, such as materials used to modify road materials. Also they're used in soles of tennis shoes, as sealants, and even in bio-medical applications. One additional use for bio renewable polymers are packing peanuts, which rather than being fabricated from polystyrene or styrofoam which has been the traditional material.

They are now being fabricated from corn or potato starch. These starch based packing peanuts function much the same way that the styrofoam based packing peanut's would. And yet, the big difference is that the starch packing peanut is biodegradable and once it's discarded, it can either be disposed of in a compost or it could be recycled.

But it will eventually degrade back to carbon dioxide and water, which is the starting materials that the plants use to create the peanut. The current market for bioplastics is relatively small when compared to the total plastics market in the US and worldwide. The good news is that the fraction of the market for bioplastics is growing every year.

And therefore there's a lot of opportunity in the development of new materials. Which can have a reduced environmental impact.
>> I think in terms of sustainability, you hear a lot of this now. If you go to a restaurant, where did that food come from, right? Or do you have a green menu?

But if you're talking about consumer products, like your plastic lunchbox or your plastic computer case, I think we should ask the same question. Hey, where did that come from? Most of it's gonna come from petroleums in the past. But if you've got polymers that come from renewable resources, it's the same thing as saying, okay, that's a free range chicken.

This is a product that did not come from an oil refinery.
>> I'm inspired to work in the area of bioplastics as I know that it is a problem that future generations will face. It's clear we're not going to run out of oil in the immediate future. However, if we start now in the development of new bioplastics, we will have time to very carefully develop methods of preparing them and optimize their properties so that they will be ready in future generations when we are reliant on these alternative resources for plastics and other materials.


>> Our perceptions about polymers are as complex as the materials themselves. If it were up to you, what message would you tell society about new sustainable polymers? Would you be able to create a new status for materials that sometimes get a bad rap?