♪
DAVID POGUE: What's it take to make our modern world?
Ah!
(Pogue shouts)
That's amazing!
I'm David Pogue.
Join me on a high-speed chase
through the elements...
and beyond.
(explosions)
Oh, my God!
As we smash our way into the materials,
molecules,
and reactions...
AMANDA CAVANAGH:It's a really cool enzyme
because it makes life on Earth possible.
POGUE:...that make the places we live,
the bodies we live in,
and the stuff we can't seem to live without.
The only thing between me and certain death...
(explosions boom, glass shatters)
...is chemistry?
From killer snails...
MANDEË HOLFORD:Just when you think you've heard of everything,
nature will surprise you.
POGUE: ...and exploding glass
to the price a pepper-eating Pogue pays.
There's got to be some easier way to learn about molecules.
♪
We'll dig into the surprising way
different elements combine together and blow apart.
(explosion)
In this hour,
we swing from the molecular chains
and surf the atomic webs that give some materials
unique abilities.
Ow...
The moldable molasses of molten glass.
(laughing): Come on!
The built-in boing of rubber.
The G-forces are indescribable.
And the menagerie of modern plastics
that these days is both a miracle...
Oh!
...And a menace.
People want to do the right thing,
but it's reallydifficult
to know exactly what to do.
POGUE: "Beyond the Elements: Indestructible"--
right now, on "NOVA."
♪
POGUE: Ah, the periodic table--
the "Who's Who" of atoms!
The stuff everything is made of
with familiar names like hydrogen,
oxygen, carbon, and iron.
But what if every substance were made
of just one kind of atom, just one kind of element?
(baby crying)
What if a human...
were made only of carbon?
(baby crying)
What if water...
were made only of hydrogen?
(terrified screams)
(loud thud, people groaning)
And what if salt...
were made only of poisonous chlorine?
(gas hissing)
(groans)
Luckily, nearly all elements like to stick together.
It's through the combination of different elements
that our world exists.
And we've made it an even richer place by learning to harness,
and even make those combinations,
to create new materials that have shaped our modern world,
such as rubber, or plastic--
materials we've come to depend on
but that sometimes come
with difficult environmental downsides.
♪
But let's start with one of the oldest
and most chemically interesting.
Look at the buildings in any city today
and you'll see-- or see through--
one of the signature materials of our times:
Glass.
♪
The Corning Museum of Glass in Corning, New York,
is home to an internationally famous collection of glass,
with examples that range from antiquity
to contemporary art.
♪
From the functional...
to the fantastic.
♪
The museum also runs
demonstrations of glassblowing.
PRESENTER: She's applying glass color to that molten glass.
By holding it to the ground,
gravity takes hold and she gets that beautiful ruffled edge.
POGUE: Some include opportunities
for novices like me
to get into the act.
ERIC MEEK:We're going to bemaking something
we call a Roman bottle.
Good, keep going,
keep going...
all right, stop.
POGUE: The kind of glass I'm working with is the most common sort,
soda lime glass,
the stuff of windows, drinking glasses, and glass bottles.
MEEK: Give the pipe a tap...
(tap)
POGUE: Whoo-hoo!
I am good at this.
Eric Meek,
one of the hot glass program managers,
breaks down the ingredients in soda lime glass for me.
So these are the raw materials
that we use to make glass.
The first main ingredientis silica sand.
You can see this is a beautifulwhite, pure silica sand.
This will make really nice,clear glass for us.
POGUE: Silica is a network of silicon and oxygen atoms,
where each silicon atom shares electrons
with neighboring oxygens,
in what are called covalent bonds.
To get this to meltat a lower temperature,
we add soda ash,so that's sodium carbonate.
POGUE: Sodium carbonate--
two sodiums electrically attracted to three oxygens
sharing electrons with a carbon atom.
If we melted pure silica
it would melt nearly at4,000 degrees.
If you add soda ash, it dropsthe melting temperature
down to around 2,000 degreesFahrenheit.
So easier for us to bring about.
Easier for usto bring about.
And then the finalingredient over here
is crushed limestone,or calcium carbonate.
POGUE: Like sodium carbonate...
(billiards break clattering sound)
but with a calcium instead.
Calcium carbonatewill help
to stabilize the glassover time. Wow!
And you just sort of mix that up in a pot.
Yup. And put it over a medium flame and...
(chuckles)It's that easy.
You mix these together,put it in a crucible,
melt it at about 2,000degrees and you have glass.
POGUE: At high temperatures,
all those powdery ingredients melt together
to form a viscous liquid that cools into glass.
But there's more to the story.
Most solids are crystalline, like frozen water,
the ice in your glass.
In ice, the water molecules are arranged in a regular pattern.
If we heat it to its melting point,
ice quickly turns to liquid,
with water molecules sliding past each other.
And then, if we drop the temperature,
the water refreezes
and the regular crystalline structure of ice returns.
Silica sand, the primary ingredient in common glass,
typically also has a regular crystalline structure.
As you heat it up, it too will melt just like ice does,
more or less all at once transitioning
from a solid to a liquid, with the network of silicon
and oxygen atoms sliding around chaotically.
But this is where glass gets weird.
When you cool our liquid silica down,
it doesn't find its way back into a crystalline structure.
Instead, it becomes an increasingly viscous liquid
with jumbled rings of atoms.
When it finally cools down enough,
that warped irregular structure becomes locked in place
into what's called an amorphous solid.
The range of temperatures in which glass remains
a viscous, goopy liquid that we can manipulate
is one reasonit's such an important material,
and has made possible the amazing art of glassblowing.
When most of us talk about glass,
we mean silica-based glass,
ordinary glass.
But glass is also the term scientists use
for any material that exists as an amorphous solid,
materials that, unlike a crystal,
have an irregular structure,
and when heated pass through a phase
that's not exactly liquid and not exactly solid.
A phase I call... gooey.
So glasscomes in many forms.
POGUE: Eric Goldschmidt,
a flame worker,
demonstrates that glass doesn't have to be, well, glass,
using a piece of hard candy.
And it actually actsa lot like glass
that we use out of ourfurnaces here.
So I'm softening thismaterial with some heat,
getting those atomsmoving around,
and it simply will neverhave the opportunity
to come back to a crystalline network.
So we can soften it a little bit.
Start to inflate it.
Start to inflate it?
(laughs)
Come on!
Dude, you're making a Roman bottle out of a Jolly Rancher!
In theory, it can be shapedinto just about anything
because of its abilityto sort of transition
from really fluid to fairly,
fairly rigid.
Would this still taste like candy?
I don't think
we've cookedthe sweetness out of it. (laughs)
Is it too hot?
It should be cool enoughto touch. (laughs)
Excuse me.
My gosh, I feel like I'm eating the wrapper.
♪
I've never had candy that light and flaky.
And I don't think I'veever had anybody
eat a piece of glassthat I've inflated either. (laughs)
POGUE:This is gorgeous.
This is, this is clearly goingto be worth something.
MEEK: Straight out.
Okay. Yup, there you go.
Maybe if I stop talkingand kept working.
There's an underappreciated aspect of glassblowing
that I learned about firsthand.
Oh ho! There we go, comes right off.
POGUE:After you shape a piece of glass while it's hot,
it has to cool slowly,
in an annealing oven
that gradually ramps down the temperature.
For something this size, it takes about 12 hours.
Otherwise differences in thickness
mean differences in cooling,
leading to stresses... (glass breaking)
That can cause the piece to crack.
But what happens if you cool some glass really fast?
♪
Then, you get these: Prince Rupert's drops,
named for Prince Rupert of the Rhine,
who brought them to England in1660 as a scientific curiosity.
MEEK: So I'm going to have you
take this hammerand try to break this drop.
Are you nuts, it's glass?
All right, so just grab itdown here by the tail,
All right, and set it downthere on the table,
and just make sure you hit,
hit the thick end. Just shatter it?
Yup.
(clanging)
Come on.(Meek chuckling)
No!
(hammering)
Wow... I broke your table.
That's insane.
We've established that this glass is indestructible.
Congratulations.
We have, but there is an Achilles' heel.
There is a way to break this.
POGUE: Considering this glass just dented a steel table,
I'm... skeptical.
MEEK: So snap it down in the tail.
This is me,
trying to snapoff the tail
of thisunbreakable glass.
(glass breaking)
(explosion echoes)
♪
What? (Meek chuckling)
Where'd it go?
It's, it's gone!
What just happened?
Well, let's rewind a little...
(rewind sound)
...to the key moment.
When the drop of hot glass enters the cold water...
(molten glass bubbling)
the outside of the glass immediately cools
and locks into shape,
but the inside cools more slowly, gradually contracting,
trying to pull in the rigid outside glass,
creating a tremendous amount of stress,
placing the outer layer under compression.
MEEK:A lot of materialsunder compression
are very strong, including glass.
POGUE: So strong, you can't break it with a hammer.
♪
But there's an Achilles... tail.
Because that part is so thin,
when it enters the water,it cools just about all at once.
No compression effect, no super-strength,
I can break it with my hands.
(glass shatters)
And that surface fracture races through
the rest of the compressed material.
MEEK: Once that compressive layer
is compromised,there's so much energy in there,
the whole thing will crack.
(glass shatters)
POGUE: Ka-blammo!
Total drop destruction!
Turns out, the surprising strength
of a Prince Rupert's drop
plays a role in how we make glass today.
Manufacturers take advantage
of the strength of glass under compression,
to make a special kind called tempered glass.
So this is a piece of commercial tempered glass,
and rather than being cooled
with water,this one is just cooled
with jets of airon the surface.
The jets of air sort of make the skin of the glass rigid,
and stiffens the surface of the glass.
The core of this cross-section
is left to cool a little bit more slowly,
and so it pulls away from the surface
and that creates a compressive layer on the surface.
POGUE: So it's sort of compressing itself
from the inside?
From the inside, exactly.
So then, what is this, like Prince Rupert's sidewalk?
It may seem counterintuitive...
Every cell in my body is saying this is a bad idea.
But by cooling the glass to create compressive stress,
generally more than 10,000 pounds per square inch,
it becomes physically stronger-- I can walk...
(groans warily)
Even jump on this tempered piecethat's about a half-inch thick.
Oh, my gosh!(Meek chuckles)
(shouts)(Meek laughs)
(laughing): What?
They could make diving boards out of this stuff.
(laughing): Oh man!
♪
Even pouring molten glass on it
doesn't make it shatter immediately,
but give it a minute...
That's some strong glass.It is.
POGUE: Or four...
(glass shatters)
POGUE: Oh man, that was cool!
It was like poof!
The molten glass finally compromised the surface.
(glass shattering) And all that built-in stress
broke up the entire sheet.
(glass shattering)
But the remaining shards are relatively safe.
MEEK: Because of that tension,
when it does break,
it breaks all the way out
to the very edge and it all breaks into these little bits.
They make these nice little cubes
that aren't nearly as dangerousas a big, broken shard of glass.
POGUE: The miracle of glass
is made possible in part by the element silicon,
the second most-common element in the earth's crust
after oxygen.
Silicon atoms have 14 electrons arranged in three shells.
Because the outermost shell has four electrons,
silicon can share those to form up to four bonds
with other atoms.
But one thing that it doesn't do well
is form a chain with other silicon atoms,
to create a compound with a silicon backbone.
It's just too reactive.
In water,the backbone easily falls apart.
The element with the best ability to do that
sits just above silicon.
Carbon can also form up to four bonds with other atoms
but luckily, it can also form strong bonds
with other carbon atoms.
The result is not only you and me, and all life on Earth,
but also a plethora of other molecules and materials
that shape our lives
and can even put a bounce in your step.
First up?
Rubber!
(engine running)
It turns out that more than half of the world's rubber
ends up wrapped around the wheels of vehicles--
motorcycles, trucks, and cars.
♪
So I've come to a place that's rolling in it...
(race car engines roar)
The Indianapolis Motor Speedway.
It's 11 days away
from the running of one of the most
famous car races in the world,
the Indy 500.
The competing teams are here, doing practice runs.
And some end better than others.
(car skids and crashes)
Before the teams hit the track,
some fortunate fans get a taste of the race.
They get to ride in a specially adapted two-seater Indy Car...
At the wheel, the legendary champion, Mario Andretti.
He's one of the most successful
American drivers in the history of the sport.
He's the only pro ever
to win the Indianapolis 500,
the Daytona 500, and the Formula One World Championship.
♪
And now, it's my turn...
♪
Imagine riding a roller coaster...
at over 180 miles an hour,
with no rails...
flying around the curves, while wondering
why we're not smashing into the wall.
♪
I've had enough after a couple of laps.
How do these drivers do 200 of 'em?
♪
Oh man, the G forces are just indescribable.
I mean you're pressed against the side
and then pressed against the back.
And when he takes the curves,
I mean there's a concrete wall coming at you, just...
(engine revs) ♪
So what's the secret ingredient to staying alive out there?
To find out,
I head to the garage that supplies the tires
in the weeks leading up to the Indy 500.
(compressed air hissing)
In 2019, each team received
36 sets of tires
for practice, qualifying, and the race-- 6,000 tires in all.
It's also a chance to talk
to the expert himself.
What I was surprised at most was
the lateral forces obviously, as a layman.
So is it, is it the rubber that's keeping us
from flying into that wall?
That it- that's what it is.
That's, the tires are obviously
the most important aspect of the race car.
These are the babiesyou want to kiss after a run. (laughs)
POGUE: At speeds up to 230 miles an hour, a driver experiences
about 5Gs of force during the turns.
That's more than what an astronaut experiences
during a space launch.
So you know the tires take a beating.
Do you know enough about
the chemistry to know what kinds of things
they can do to the compounds?
Like what sorts of things do they add?
If they would tell me that,they would have to kill me.
(laughs)
Hopefully, that's not a blanket policy
because I've come to Akron,Ohio, looking for some answers.
Harvey Firestone founded the Firestone Tire
and Rubber company here in 1900.
Bridgestone Corporation bought it in 1988,
becoming Bridgestone/Firestone.
This is one of its research facilities.
And Laura Kocsis is one of its scientists.
According to her, it all starts with this.
I got to say,this feels rubbery.
And it... oh, man, it's also stinky!
Yup, so that's natural rubber.
Oh, this is what comesout of the tree?
Yup, so it comes out of the tree, we process it,
and it turns it into what you have in your hands right now.
It becomes this. Yes.
♪
Natural rubber begins
as sticky, runny, white liquid called latex.
It's found in more than 2,000 plants, including dandelions,
but most of the world's natural rubber
comes from trees like these,
the Hevea brasiliensis,better known as the rubber tree.
Natural latex is about 55% water
with particles of rubber suspended in it.
And if you could zoom into one of the particles...
you'd see it's like a tangled bunch of spaghetti.
Each noodle is a long molecular chain called a polymer.
To get to a polymer, you start with monomers,
which is one chemical unit, and that's represented by
these paperclips here.
This here isone chemical unit?
Yup, consider that one chemical unit.
Meaning what--a molecule?
Yup, one molecule.
So for natural rubber,what,
what molecule are we talking about?
So we're talking about isoprene.
Isoprene, okay. Yes.
Here's what isoprene looks like:
it's a molecule with five carbons bonded to each other
and to eight hydrogens.
In natural rubber, isoprenes are bonded together,
one after another, to make a chain-- a polymer--
just like the chain of paper clips Laura showed me.
Once you get to tens of thousands of these units
linked together, you end up with natural rubber.
Oh, tens of thousands? Yup.
Okay. Tens of thousands.
POGUE: In their natural state,
the rubber polymer chains can become easily entangled
as they coil up.
But when you stretch them out,
the chains straighten out
and align themselves in the direction of the stretch.
Let them go,
and the molecules return back to their coiled-up states,
giving rubber its signature
"boinginess."
So if it's rubber,it should be a little boingy.
Yup, it's going to bounce.
Ah!Okay, that's,
that's very boingy.
I'm sure here at Bridgestone,
you use that as a chemical property,
the boinginess.
Yes, very technical.
And... oh...
(laughter) Oh, man.
Natural rubber is often an ingredient in tires,
but it's not the only one.
Today, many tires include synthetic rubber,
made out of other monomers
not found in latex.
♪
POGUE:Oh ho!
I'm sensing more polymers.
Yes. More chains of molecules.
What do these represent?
So these are different configurations of
polymers that we can make in our laboratory.
Natural rubber is made of only one type of monomer.
Here we can use different types
and bring them together with our chemistry.
And each way of linking themtogether
produces different qualitiesin the tire that will result?
Yup, so maybe the amount of monomer can make a difference
in the properties, how they're configured
can make a difference, andthat's basically what we do here
is find different ways of putting them together
so that we can achieve the properties that we want.
Wow.
Natural rubber, synthetic rubber,
turns out, there's even more that goes into tire rubber.
Here in the test lab,
technicians mix all the ingredients together.
Like carbon black and silica,
which reinforce the tire.
Another key ingredient is sulfur,
element number 16 on the periodic table.
The resulting blob
then gets rolled into sheets...
cut into squares for testing,
and baked at high temperature
in a process called vulcanization.
Charles Goodyear discovered the process in 1839
when he accidentally spilled
a mixture of rubber and sulfur on a stove.
He named it after Vulcan, the Roman god of fire.
(bell chimes)
♪
Cooking the rubber-sulfur mixture
causes the sulfur to chemically bond
the rubber's polymer chains to each other,
forming crosslinks between them.
♪
Bill Niaura, Bridgestone's Director of Innovation,
shows me the result.
So this little bowtie,this was cut out of
one of those squaresbefore vulcanization.
NIAURA: It was.
And this is what rubber lookslike after that vulcanization?
Correct.
So, the only differencebetween these two
is this one was super-heatedfor a while.
Correct.All right.
And according to you, somethingproperty-wise has changed?
It has.
Why don't you take the uncured one and stretch it.
All right, this guy.
Just pull it?
Oh, wow.
What you'll feel are the polymer chains flowing apart,
it's acting like a liquid, it's viscous.
It feels exactly like gum, stretching gum.
And when you release the force...
(laughs) ...you'll see that it's flowed apart and the energy
that you put in has not been recovered
and the piece has been permanently deformed.
I broke your rubber sample.
I'm okay with that.
POGUE: With all the new ingredients, our unbaked tire mixture
is far less boingy than the rubber I saw in Laura's lab.
When you stretch it,
the mixture's loosely coiled polymer strands
slide past each other and keep on sliding.
Only weak interactions holdthe network of strands together,
so under stress, it pulls apart.
Okay, and then after vulcanization, same test?
Indeed.
Oh, man, it's much harder to pull.
And when you release the force...
Oh!
...you'll see that it's recovered its original shape,
and that's a characteristic of elasticity.
♪
POGUE: Stretch out this vulcanized interconnected web of strands,
and instead of ripping apart,
the network springs back to its original shape.
NIAURA: Right. It's a cross section.
POGUE: But as Bill shows me,
with cross-sections from different tires,
vulcanization doesn't just connect up
individual rubber molecules,
it connects up everything in the whole tire mixture.
NIAURA:As we cure the tires,we heat it.
That vulcanization reaction not only cures the rubber
within a compound,
it cures across compounds
to connect all of that into, into one unit.
In the end, it's essentially one molecule.
The whole tire? It is.
The whole tireis a molecule? It is.
(laughing):Well, how is thata molecule?
So a molecule
is a collection of atoms that are chemically attached.
Yeah.
We've done that through polymerization,
we've attached monomers to make polymers,
and then through vulcanization,
we've attached the polymers to make the finished product.
So I guess, therefore,since this is all connected,
molecularly linkedto molecularly linked,
it is one giant molecule?
It's beautiful.(laughs)
(engines roaring)
POGUE: Now that I know just how much engineering goes into
those giant tire-shaped molecules,
I have a new appreciation
for the rubber that keeps us all on the road.
And for the people behind it, like Cara Adams,
director of race tire engineering and production
for Bridgestone/Firestone.
She oversees the race tire operation, including Indy.
♪
Although interviewing her at theoffice turns out to be... tough.
One of the things that you're trying to look at
with a race car is aerodynamics.
(race car approaching)
If you think about a tire, those are the only
point of contact between the cars and the ground out there.
(race car speeding by)
That was a very small four-inch wide rim so...
(race car speeding by, Adams' voice become inaudible)
(another race car speeding by)
This is what you get for trying to film at a racetrack.
POGUE:Yes, exactly.
So we move to a somewhat quieter place.
We think of car racing as excitement, and adrenaline,
really cool.
How much actual science is there to it?
Well, there's a lot of science and chemistry
and that actually goes in the tires.
So we have engineers that work with physics
to make sure the tiresare strong enough.
And then we have people that are really smart in chemistry,
and they are actually ableto design those tread compounds
that are running at 240 miles per hour
and adhering to the ground.
It's really exciting.
So are you trying to tell me that the only thing
between Mario and meand certain death is chemistry?
Chemistry and physics,absolutely.
(laughs)
POGUE: Both the natural rubber and synthetic rubber used in tires
are elastomers, polymers with elastic properties.
They allow tires to be both flexible and durable...
(loud screeching)
...marvels of engineering.
But they have their limits.
(loud pop)
♪
So what if you need an elastomer that can hold it together
no matter what you throw at it?
Michael Tidd from the company LINE-X has invited me here,
a lift in a back lot inWest Springfield, Massachusetts,
to see an elastomer that can be a protective coating.
The day begins
with a tale of two pumpkins.
Pumpkins seem like they are already blessed
with a certain degree of protection.
Nature has provided a pretty good membrane
but I don't... I don't knowif it was in the original design
to drop it from 50 feet. (laughs)
Well let's doa "scientifical" test.
We could always give it a try and see what happens.
On three, ready?
One, two...One, two...
Three!
(David laughing)
POGUE: Well no surprise here...
(laughing):It's... it's a squash vegetable and a floor wax.
That was the control
of a uncoated pumpkin as youwould find them in nature, yes.
♪
POGUE: Now it's time for a pumpkin covered with Michael's
protective LINE-X coating.
I have to say, it feels a little bit like plastic.
It is a lot like plastic.
It has characteristicsof plastic.
However, it is an elastomer,
which means it could bestretched,
but it will return to its original shape.
Uh, let's see if thishas any better effect.
One, two, three!
(David laughs)
♪
The LINE-X-coated pumpkin
flexes to absorb the impact
then springs back into shape.
We try a few more household objects.
This experiment is entitled "When Pigs Fly".
(shatters loudly)
Can you guess what will happen to the egg when we drop it?
♪
The flower pot's last moments.
♪
And I run a few comparisons myself...
♪
(grunts)
Finally... bringing out the big guns.
♪
No way...
(voiceover): Okay I get it.
The stuff is tough.
But what's going on inside that coating?
Did the objects survive intact?
(saw whirring)
Michael cuts open our dropped pumpkin
to see the state of affairs...
(whirring continues)
(whirring stops)
(David laughs)
It's pumpkin pudding!
A lot of damage.
So, the pumpkin is gone,but the coating did just fine?
Correct
But when would you care about
not protecting the gutsof something
but the outside is fine?
A lot of times, we will put it on a membrane,
such as a wall or a floor
where we're trying to protect what's on the other side.
POGUE: Here's a test of that idea.
This simulated car bomb blows down an exterior wall.
(loud explosion)
♪
But with a coating of LINE-X on the outside
and the inside of the wall...
(muffled explosions)
...it becomes more of a dust-up.
♪
So what is this stuff?
Well there's more than one flavor of LINE-X,
but the coating on our power pumpkins is the result
of a reaction between two ingredients.
The first is a highly reactive molecule.
♪
At each end of its carbon backbone,
there's a nitrogen, carbon, and oxygen group
called an isocyanate that acts like a hook to lock onto...
the second chemical ingredient.
It's a polyamine-- a member of a chemical group called resins.
LINE-X heats the two ingredients
and feeds them under pressure
to this sprayer,
which mixes them just as they exit.
Immediately, the first ingredient hooks on
to part of the resin, and all those linkages create
long entangled polymer chains similar to rubber
so that they're flexible but also much tougher.
The resulting elastomer is called a "polyurea"--
a cousin to the more familiar polyurethanes.
So, that's the general idea,though they tweak the chemistry
for different applications.
Most of LINE-X's consumer business
is spray-on truck bedliners.
Not so much for protecting produce
or making kid's toys last... forever.
♪
The main ingredients for LINE-X and synthetic rubber
come from fossil fuels like refined crude oil.
When we pump oil from the ground,
it's a rich soup of molecules
built around that tinker toy wonder element-- carbon.
They come in chains, rings, trees, and other shapes.
Refining separates those molecules by kind,
and in some cases, breaks up bigger ones,
turning them into smaller, moreuseful molecules, like gasoline.
Refining also supplies industry with the basic building blocks
for another group of synthetic polymers
that came to dominate our way of life in the 20th century--
plastics.
Today, plastic is everywhere.
You can find it in tea bags...
ribbon...
the inside of paper coffee cups...
sunscreen...
toothpaste...
sponges...
most clothing...
the fish you eat...
...and even salt.
Malika Jeffries-El plays with the molecular building blocks
of plastic for a living.
She's a polymer chemist at Boston University.
So clearly, there's all kinds of
different plastics,
but is there something
that unites them all that makes a plastic a plastic?
Plastics are a subset of polymers,
in that they're known not just for having their
macromolecular structure
but the processing and mechanical properties
that come from, as a result of that structure.
Like bendy-ness and...Exactly.
...strength.Exactly.
Strength, exactly.Strength, flexibility,
rigidity would beanother property.
POGUE: Like rubber, all plastics are polymers--
long molecules made up of subunits called monomers.
What makes each of thesepolymer-based materials distinct
are the combinations of the different monomers
used to make them.
For example, this is actuallyreally hard and rigid,
and one of the units in hereis styrene,
and this is polystyrene.
Not hard and rigid at all.
Not hard and rigid at all,
but when you blend in the other molecules,
you get different properties.
Wow.
POGUE: But it's not all chemistry.
Processing can turn the same plastic
into very different products.
JEFFRIES-EL: These were actually molded and blown into this bottle shape,
and in this case, really small fibers were spun
from the polymer and then processed to make this.
And it comes out soft and comfortable.
Comes out soft and comfortable.
POGUE: Our Age of Plastics isn't very old.
It was this guy, Leo Baekeland, who gets credit
for the first fully synthetic plastic.
He called it Bakelite,
and by the 1920s, it had become a big hit
in all kinds of products--
from radios to kitchenware...
to kids' toys...
and coming in a variety of colors.
Malika has offered to whip up some of this landmark plastic.
It's made from two monomers: phenol,
a ring of six carbon atoms bonded to five hydrogens,
and an oxygen bonded to a hydrogen;
and formaldehyde,
one carbon atom bonded to two hydrogens
and double bonded to an oxygen.
After dissolving the solid phenol
into the formaldehyde solution...
Malika adds two acids to start up the process.
Then we wait.
JEFFRIES-EL: There should kind of be this "a-ha" moment
and it should just go.
POGUE: Are you saying it's gonna harden?
Yeah, it should get cloudy
and polymer should come crashing out.
JEFFRIES-EL: I feel like it's getting pinker,
which is an indication that the chemistry is changing.
POGUE: Oh! Did you see that!?
Like instantaneously!
Right before our eyes, the phenol and formaldehyde
molecules link up, giving off water molecules
while creating long polymer chains.
You made plastic!
Look at that.
Genuine, crusty, hard,
hard plastic.
JEFFRIES-EL: So this is an example
of a thermoset plastic.
Once it's set into place with heat,
you can't reform it
or reshape it with additional heat.
Oh okay, so this... so unlikea plastic drink bottle...
That's right.
...you can't melt this down and reform it into something else.
No.
This is Bakelitenow and forever.
That's stuck like that forever, yup.
♪
POGUE: In a thermoset plastic like Bakelite,
the bonds between the polymer chains are extremely strong.
By the time you've applied enough heat to break them,
the chains themselves have decomposed.
So you can't re-melt thermoset plastics
or reshape them for recycling.
But not all plastics are thermoset.
There's nylon,
the first commerciallysuccessful plastic that wasn't.
It came to public attention at the 1939 World's Fair
as a substitute for silk in women's stockings.
And its importance grew during World War II.
At the time, the main source of silk for parachutes
was America's enemy-- Japan.
So the military recruited nylon as a replacement.
Malika offers me some firsthand experience making nylon.
If you want to make nylon, don't you need, like a factory?
Well if you want to makea lot of nylon, yeah,
then you're going to needa factory.
But if we're just goingto do a demo,
we're going to make a little bitof nylon and we can do it
in a little beaker. All right, like for...
for mouse stockings.
Yes, exactly.(laughs)
To do this we're going to mix together two chemicals.
POGUE: There are lots of variations on nylon.
Our two key components will be two molecules that are
simpler than they sound--
hexamethylenediamine
and adipoyl chloride.
Since they each have a six-carbon chain...
we're making what's called Nylon 6,6.
JEFFRIES-EL: So the first thingwe're going to do is we're going
to add the hexamethylenediamine.
POGUE: So mostly colored water.
Mostly colored water
with some cool organicsin there. All right.
And then we're going to addour organic layer
of the adipoyl chloridesolution.
And because the densityof this
is less than thatof the water,
it should float
on the surface of the water.
Kind of like oil and vinegar.
POGUE: Where the two liquids meet,
the molecules of the hexamethylenediamine
and adipoyl chloride link up,
one after another, releasing hydrogen chloride as a gas.
Malika gives me the honor
of pulling the newborn nylon polymer out of the beaker.
And as more of the two liquids come into contact,
they make more nylon.
Do you have a ladder, Malika?
There you go. Look at that.
Freshly baked, free-range nylon.
Amazingly,
this really is a junior version of how bulk nylon
is manufactured.
All right...
anyone need stockings?
Unlike Bakelite,
nylon is an example of a thermoplastic,
which we can reheat and reform.
That's the basis of some plastic recycling.
Malika wants to show me one more example.
And this time what are we going to make?
Um, so for this demonstrationI thought I would show you
how we make polyurethane foams.
And what do we use polyurethane foam
for in the world?
Polyurethane is usedin like seat cushions, uh...
and also insulation.
You think about like blown foam and things like that.
Oh yeah.
(imitating E.T.): E.T. blown foam.
Yeah, I remember that.(laughing)
♪
POGUE: There are two key reactants.
First up is a type of molecule with an oxygen-hydrogen hook
at either end.
Aside from its role in polyurethanes,
this one shows up
in paintballs
and laxatives too.
The other reactant we've already met at LINE-X--
that carbon-backboned isocyanate molecule
with the nitrogen/carbon/oxygen hooks at either end.
JEFFRIES-EL:And we stir this together.
And so you can already seeit's starting to react
because it's starting to get
milky and it's starting to grow in size.
You can see it's rising up a little bit.
POGUE: The two molecules begin to link up to form
a polyurethane polymer.
♪
At the same time,
one ingredient also reacts with some water
generating carbon dioxide gas.
That's what causes the bubbling
and ultimately the foam when the polyurethane grows rigid.
♪
I know I'm tacky but...
(chortling): Oh!
And the cup's entombed inside there.
(chuckling):Yeah, the cup is...the cup is gone.
POGUE: Pretty cool, but it's just a start.
Because when in foam...
do as the... Foam-mans do?
♪
(David cackling)
♪
There we go...
Years of snowman training.
(Malika laughing)
We'll open a 529 plan, we'll buy some diapers...
Nothing but the bestfor you.
He has your smile.
(laughing uproariously)
♪
POGUE: At this point...
Polycarbonate.
POGUE: ...you're probably getting the idea.
Polyethylene terepthalate--
P.E.T.E.
POGUE: That there are lots of different plastics...
Polyvinylchloride--
PVC.
POGUE:...each made out of polymers...
These are examplesof polyamides.
Commercially known as nylon.
POGUE: ...constructed sort of the same way...
Polystyrene.
POGUE: ...but out of different subunits...
Polypropylene-- PP.
POGUE: ...to obtain very different material properties.
Low-density polyethylene--
LDPE.
POGUE: And then if you start throwing in additives and fillers...
Polyvinylalcohol--
PVA.
POGUE: ...like colorants...
High-density polyethylene--
HDPE.
POGUE: ...flame retardants, glass, or carbon fibers...
Polymethylmethacrylate--
PMMA.
POGUE: ...you end up with tens of thousands
of grades of plastic...
Polyoxymethylene--
P.O.M.
POGUE: ...each tailored for a specific purpose.
Which has created the problem--
what do we do with them when that job is finished?
♪
Mostly, we throw them out.
91% of all the plastic we make ends up in landfills....
...or burned...
...or just escapes into the environment.
The remaining 9% is recycled.
But first, the plastic has to be carefully separated by type,
those recycling number symbols.
Any mix-up there can contaminate an otherwise reusable plastic,
rendering it worthless.
And there aren't many places willing to do
that separating work.
In 2018, China stopped accepting shipments
of bulk unsorted plastic from the U.S.,
or anywhere else in the world.
With the economics of recycling in turmoil,
lately the discussion hasshifted to single-use plastics,
about half of all the plastic we produce.
Much of it is food related.
To learn more, I travel to the University of Georgia
to meet Jason Locklin, a chemistry professor
and the director of its New Materials Institute.
Well, thanks for meeting me here, Jason.
I brought you breakfast.All right!
POGUE: Well, breakfast and a bag of single-use problems.
This is called
a clamshell container.
Less than 1% of all polystyrene is recycled globally.
If this makes its way into the landfill,
which is exactly where it'll go,
it'll persist thereforever.
We have a plastic straw.
It'll stay there for hundreds,if not thousands, of years.
Is that really a way
to design packaging--to have a material that you use
for ten seconds,
and then it goes to a landfill for a thousand years?
POGUE: Even packaging that looks recyclable,
like paper takeout containers, may not be because...
well, they have to hold food.
LOCKLIN: If you put food into
a paper towel,what happens to it?
It's going to get soggy and fall apart.
Exactly.
So, in order to make thisa takeout container,
we have to coat it with plastic.
It essentially prohibits our ability to recycle it.
Wow.
So is there any solution
to that problem?So here's just an example.
If you pull the filmoff that plastic,
this is aboutwhat it looks like.
But this film is madeout of a material called PHA.
POGUE: PHAs--
polyhydroxyalkanoates--
are a type of plastic produced from polymers harvested
from certain bacteria.
For the bacteria,
the polymers are essentially kind of like fat,
a way to store energy.
But, because they come from bacteria,
PHAs have a huge advantage.
They're completely biodegradable.
Researchers in Jason's lab are among several scientists
and companies around the world developing
a PHA-based coating that could replace
the traditional plastics
that often make our take-out boxes unrecyclable.
Although the cost of PHAs still needs to come down
to be competitive.
And finally,what does Jason think about that
eco-friendly-looking green bag I brought breakfast in.
This is a great exampleof some absolute green washing.
"Biodegradable."
You see it in big, bold claims.
If you read the fine print,
it says, "49.28% biodegradation in 900 days
"under non-typical conditions.
No evidence of further biodegradation."
(laughing): Come on!
That sounds like a total scam.
But look at the size of the green leaves!
That makes me feel good about myself-- it has a leaf on it.
This is simply adding to the confusion
of people like yourself, people in the general public,
that want to do the right thing.
This makes it really difficultto know exactly what to do.
♪
POGUE: Oh!
When it comes to creating new materials,
we may be the victims of our own success.
It was like poof!
We've invented some that are useful and so durable...
that they last more than a human lifetime.
And now we're drowning in them.
But attitudes are changing
with engineers and chemists harnessing
biology to combat the problem.
In the end, the human ingenuity that helped create
the current crisis
may help solve it as well.
The only thing between me and certain death is chemistry?
♪
As we move "Beyond The Elements."
♪
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♪