My Interview with "The Polymer Babe"

Today I have a very special interview with "The Polymer Babe". Apparently she is the twin-sister-separated-at-birth of "The Food Babe". I think you will soon seen the similarities in their looks and personalities.

The Polymer Babe

John: You have some strong opinions about what should and should not be in polymeric materials. Can you explain?
Polymer Babe (PB): Certainly. I believe that nothing that can be eaten or drunk by a person should be in polymers. No food whatsoever.

John: Why do you feel this way?
PB: Well, years ago I was always having problems with processing polymers. They were gassy, they would sometimes be difficult to pass...er, through an extruder die or gate and so on. In general, I just didn't feel well. So I started reading the ingredients list, and Wow! was I surprised. Did you know that water-based polymers contain water?

John: Yes, yes I did
PB: Well, once I got rid of the water, all my problems went away. So now I had proof that human consumables should not be in polymers.

John: Proof?
PB: Sure. Isn't it obvious? It worked one time for me - what more proof do you need?

John: I have a slightly higher standard for proof, but let's move on. Have you since found food and human consumables in other polymers as well?
PB: Did I ever. Some were really easy to find, such as polyvinyl alcohol. Alcohol! That plastic is loaded with alcohol. Did you know that you can get drunk on it? Once this become more widely known, how long before kids start taking shots of Elmer's glue for a buzz? I've stopped working with polyvinyl alcohol and as expected, everything processes better for me. And I feel better.

John: Any other examples?
PB: Oh, I'm just getting started. Some of the examples of food-containing polymers could only be discovered if you know a just little bit of chemistry, like I do. Have you ever thought about polyvinyl chloride? You might think it's food-free, but it isn't. What's table salt? Sodium chloride. Chloride - chloride. See the connection?

John: Are there are other examples of how knowing just a little bit of chemistry has helped you?
PB: Of course. There was the one time when I was working with a contract coater on drying a solvent-based coating in a convection oven. I asked them them to use heated air, but there were problems and the coating never dried properly. You know what I found out afterwards? They weren't using pure air at all! They were using this cheap mix of gases that was like 78% nitrogen, 21% oxygen and with a bunch of other gases mixed in too. I insisted right then and there that they use pure air in the future, but they kept blaming the problem on me and my formulation. But I was right and I know it. Since I showed them their ignorance about the difference between pure air and the diluted mixture they were using, they have had runaway success with their business. They are now so busy with other customers that they can't fit me back into their schedule. They keep saying they are booked solid for the next 10 years.

I can give lots more examples, but I really want people to buy my book, opps, I mean, read about them in my book.

John: I didn't know you had a book out.
PB: Yes, it's called: "The Polymer Babe Way: Break Free from the Hidden Toxins in Your Polymers and Have your Parts Lose Weight and Look Years Younger Because You Did Accelerated Aging Properly in Just 21 Days!"

But more importantly, I'm also coming out with my own line of polymers that are food-free. For instance, I have a line of hydrolyzed polyvinyl acetates that are a great alternative to polyvinyl acetate. They really are a drop-in replacement, but they are completely free of all vinyl alcohol. And I have a polyvinyl chloride line that I make with chlorine gas, not chloride.

John: But how is that any different than what the rest of the industry is doing?
PB: And you are just an industry shill, aren't you? That's why I know I'm right. The more people criticize me, the more I know I am getting closer to the truth.

John: I'm sorry, I didn't mean to upset you. I know you have to go to another interview, so do you have any final words?
PB: No amount of food or drink is safe in polymers. No amount. None. If my grandmother can pronounce the names of the ingredient, they shouldn't be in plastics.

John: Thank you for your time, Polymer Babe. I found this interview...er...well, what I think I mean to say is this: when it comes to your knowledge of polymer chemistry, I'm at a complete loss for words, and I think my readers would agree. Maybe we can do another interview in the future? I'm booked for the next 10 years, but the year 2026 has a few slots available?
PB: Thank you as well. I'm sure that by 2026, I will have even more impressive discoveries to talk about, and it's all because I know just a little bit about chemistry. Pretty impressive, huh?
John: I'll say. Until then.

Previous Years

March 27, 2014 - One Beautiful Salt Mine

March 27, 2012 - Is "Plastics-to-Oil" recycling?

Is Kim Jong Un the next Queen of England?

One of the claimed advantages of polymeric currency is the increased difficulty to forge the notes. While forging the notes might be more difficult, it is apparently pretty easy to alter them as can be seen in this image:

Source

I think it's a pretty well done. It's just a little bit early for April's Fools day however. (Know anyone brave enough to ask him for his reaction?)

Previous Years

March 25, 2014 - More Exaggerations about Ocean Trash

March 25, 2010 - What Are The Odds?

Plastics Recycling - Good News and Bad News

A couple of recent online reports highlight the "interesting" times that plastics recycling faces. (By "interesting", I'm referring to the infamous non-Chinese, Chinese curse of living in interesting times.)

First, the good news: The American Chemistry Council is reporting that the recycling rates for plastic films took a nice jump up last year of over 11%. The research organization that performed the study "attributes the gain to a combination of increased collection and more comprehensive reporting." This is pretty important news however, as plastic films are at the frontline in the battle against plastics, i.e., plastic bag bans. I see more and more opportunities of plastic collection sites, such as at the entrances of Target, Walmart and local grocery stores, so there are few excuses for everyone to not stuff the bags in there. (I happen to have a good excuse - I reuse the bags by picking up dog poop.)

But now comes the bad news. Low oil prices are putting a strain on recyclers. Since the price for virgin resins are falling, the price advantage of using recycled resin is disappearing.

Low oil prices will not last forever. The Saudi's have a lot of cash in the bank to live off of, but it won't last forever, so the strain on recyclers will also not last forever. But I am hopeful that the increase in plastic film will continue into next year and beyond.

Previous Years

March 23, 2011 - EVA vs. VAE

March 23, 2010 - Automotive Plastics

March 23, 2010 - Is this a Dagwood?

March 23, 2009 - Natureworks is expanding

March Madness: Brought to you by Plastic

The United States right now is going through "March Madness", the time of year when the annual college basketball tournament takes place. 64 teams are placed in a single-elimination bracket and over 3 weeks, the national champion is decided. But that is not "the Madness". Instead, "the Madness" comes from all the betting pools that are formed in the workplace or with friends. You get a empty sheet with the pairings and have to pick the winner of all 63 games before the first whistle is blown (more on that in a minute) for the first game. If you pick the Drooling Nazg�ls from Big State U to win it all and they are eliminated in the 1st round by the Biting Gnats of Tiny Town University, well, better luck next year since your bracket is blown. Correctly picking brackets is rather difficult, and basketball junkies who put a lot of thought into the matter are often made to look foolish by a spouse who picks their teams based on the mascots or the teams jersey colors.

The New York Times yesterday had an article about a tiny piece of plastic that plays a tremendous role in the tournament - the whistles used by the referees. I always figured that the whistle were metal and a had a little ball (called a pea) inside. Wrong and wrong. They are plastic and pealess. Being pealess means that the pea can't get stuck to an interior wall due to saliva or dirt building up (or the official blowing too hard!). Being pealess also means that the internal geometry is pretty complicated and molding it from plastic is a necessity. Here's a look at the one of the drawings from the US patent covering the whistle (# 5,816,186)

The two parts need to fit together to form the main chamber. Could you make this from metal? Probably. Is it worth it? Hardly.

The article revealed an interesting twist about the whistles used in this basketball tournament. They are not entirely plastic. (Gasp!)

"Each whistle hangs on a lanyard. And just below the whistle is a clip that holds a black wire with a tiny microphone. The wire is wrapped around the lanyard, tucked inside the collar of the official�s striped shirt, and plugs into a box clipped to the belt.

It is the Precision Time System, invented in the 1990s by the former N.B.A. referee Mike Costabile. Each time the referee blows the whistle, the game clock, if it is running, stops. To start the clock, the referee reaches to the box on the belt and pushes a button.

It is choreography that few fans notice. But eliminating the reaction time of a clock operator on the sideline � who pushes a button after hearing the whistle � saves at least 30 seconds of action in a 40-minute college game, tests showed."

I'm not so sure that that extra 30 seconds is worth it to me. After all, it would have changed the outcome of the SMU/UCLA game in a way that would have significantly favored my bracket selections. Well, better luck next year.

Previous Years

March 12, 2013 - Lubricating liquids

March 12, 2012 - The Mixed Up World Views of Paracelsus

3-D Printing has a New Competitor

I won't be so bold as to say that 3-D printing as we know it died on Monday [1], but it certainly took a good body blow (open access article after registration). Take a look at this video and you decide:
Pretty neat, huh?

That this is a UV-cured acrylate may not be overly surprising. By judicious choices in the monomers and photoinitiators, acrylates can cure pretty quickly. But the big question is how is the curing controlled to create such detailed topologies? 2-Photon absorption is one option, but it is a very slow process. So what is the key here?

Like any magic trick, once you know the secret, it seems pretty simple [2] and this is no different.

The picture on the right shows what is happening in the liquid pool. The real secret is the yellow piece at the bottom which is Teflon AF 2400. Not only is it highly permeable to oxygen, but it is also UV transparent. With photopolymerization of acrylates, UV and O₂ will take you in two different directions. The UV will cure the acrylates, while the O₂ will inhibit the polymerization.

Knowing all this, it's pretty easy to connect the dots. The oxygen creates a "deadzone" just above the Teflon, while the UV creates a "livezone" just above the deadzone. By having an array of UV light sources under the Teflon with the ability to control which elements of the array are on and off, you can then control the formation of your object.

Being that this is acrylate chemistry, there are an endless number of monomers and comonomers available to make materials with a wide range of mechanical properties. You are not locked into a limited range of mechanicals, but you do need to have a system that is O₂ inhibited. Throwing in some thiol-based monomers for instance, will ruin everything. Also, unlike standard 3-D printing, the use of monomers may limit the use of this technique to industrial users, at least initially. But regardless, this is some exciting new technology and I can't wait to see where it goes.

The researchers have named this process "CLIP" (Continuous Liquid Interface Processing) and have started their own company with a flashy website if you want more details or want to see more cool videos.

Since this post transitioned to the business side, I was curious at to what this announcement did to the stock price of existing 3-D printing companies, such as Stratasys or 3-D Systems. Apparently nothing. On Monday, Stratasys opened at $57.77 and is now at $58.34 having been as high as $60.49 late yesterday. 3-D Systems is behaving the same way. That is not what I would have expected, but picking stocks has never been my strength [3].

Update: I forgot entirely to mention that @Chemjobber pointed this article out to me. Mea culpa


[1] After all, Gutenberg's movable letterpress printing method is still being used 576 years later.

[2] For some people, knowing the secret to a magic trick ruins it. Not for me.

[3] Don't ask me to pick NCAA Basketball brackets either.

Previous Years

March 19, 2014 - "Openness in Science"

March 19, 2012 - Plastics Recycling Conference

March 19, 2010 - Another Use for FTIR in the Medical Lab

March 19, 2009 - Nitrogen Enriched Gasoline???

A Bridge Too Far for Fiber-Reinforce Polymers

An anonymous reader alerted me to a news story that features polymers in a novel use, but at the same time, not in a good light.

The story concerns the Morrison Bridge in Portland, Oregon, one of the most heavily used bridges in that state. The bridge is a double-leaf bascule bridge. For these types of bridges, there is a counterweight that is used to lift the leafs. This places restrictions on how heavy each leaf can be. The original bridge surface was made of steel grating, but was slippery and led to accidents. Concrete or other solid surfaces would be too heavy for the counter weights, so the local county decided to replace it with a new deck made from a multitude of polymeric materials, as seen here:

The pink T-beams and the blue upper deck are all polymeric. I don't have all the details but the material is an FRP, fiber reinforced polymer.

Almost immediately after installation, the surface started to fail. Which led to complaints. A blame. And fingerpointing. And the inevitable lawsuits. A recent article in the Portland Mercury goes into great length about the fingerpointing and the there are plenty of fingers everywhere you look. There is: Conway Construction, who designed the leafs; ZellComp, who sold the decking; Strongwell, who made the decking and Hardesty & Hanover, who designed the decking. The article is pretty well done in general and has some pretty dramatic video showing how the decking has failed in certain spots at the top of the T-beams. The bridge was in no danger of collapse, but failure of the decking could lead to car damage and accidents.

The article fell short however, when it comes to one technical detail, maybe one that was crucial to the jury: the difference between a crack and a craze.

"But there was a more apparent problem with the decking, once it arrived in Portland: It was already cracked....The argument Strongwell and ZellComp would wind up making�to county officials and in court papers�is that the cracks weren't important. To this day, they don't even call them 'cracks' if they can help it. To the companies, the distressing-looking seams were something called 'crazes,' harmless irregularities that sometimes show up in the type of polymer used on the Morrison."

There is a big difference between a crack and a craze. A crack is a crack, but a craze is a small semi-voided region where there are still fibrils extending across it. A crack cannot support stress, while a craze can (as the University of Portland verified with their testing of the crazed sections). This picture nicely illustrates the difference:

So to suggest that the suppliers are being nefarious for not using the word 'crack' is really not appropriate.

The lawsuit was recently decided by a jury. They found Zellcomp, the County, Hardesty & Hanover and Conway Construction to be negligible to varying degrees, but not Strongwell. I don't know why Strongwell was not found as a contributor. Maybe the whole crack/craze difference was a factor?

The county is in a pickle now however. Because of the fundamental design of the bridge, they have to still work with lightweight leafs. Which means they are still considering polymeric materials. And since these are new materials, the number of suppliers is very limited. In fact, they are limited to ZellComp and Strongwell. Maybe it's time to blow up the bridge and start with a design that is without such constraints?

Previous Years

March 18, 2013 - Rheology, Beer and Motor Oil

March 18, 2011 - Mental Models

March 18, 2010 - Real World Recycling Issues

March 18, 2009 - So you want to win an race of Epic proportions?

March 18, 2009 - Chaos Theory and the Big Three

A Difference of Opinion over Chemical Composition?

Plastics News is reporting that the Chinese plastics industry is complaining about remarks made on a popular Chinese TV show. Specifically,

"The health-themed show, which aired on government-owned Beijing Television, claimed that bottles marked with a No. 1 at the bottom � PET bottles � contain toxic plasticizers that can leach out in a low-temperature environment such as in a refrigerator and may cause cancer. A guest on the show also claimed that high density polyethylene food packaging contains a lot of plasticizers."

Both of those statements are laughably false.

Of course, the TV shows statements can easily be supported by analytical data, but the TV show has none. Instead,"...the producers brought English-language literature supporting their claims. However, they refused to give a copy of all materials to [the Chinese Plastics Processing Industrial Association]". So no data? Just some statements written down somewhere else? This follows the old line that "if someone took the time to write it down, it must be true". [*]

But this is the kicker:" 'We think our opinions are fine, not incorrect, just different views,' one producer said." No, that is not the case at all. One of the hallmarks of science and analytical science in particular, is that it is not subject to opinion. The analysis will be independent of your national origin, your political views, your sexual orientation, your faith, your diet, your age, your race, your criminal background, your income and even whether you are a TV producer or not.

I've always been lukewarm about science education in public schools. You don't really learn enough to make a significant difference. Speaking as a chemist, you really don't start learning significant stuff until your sophomore year in college. But the reason I do end up supporting it is for everything that I said in that long sentence above. Students need to learn that science is not subject to opinion or any of the other factors I listed off and a whole slew of factors that I didn't list. If high school students can just learn that, that is far more important than anything else that they will learn in a high school chemistry class.

Unfortunately, not enough teachers emphasize that here in the US. And that appears to be the case in China too.

[*] The more modern version being "if it's on the internet, it must be true". [†]

[†] The even more modern version being "if it's on Wikipedia, it must be true".

Previous Years

March 12, 2014 - If It Ain't Broke, Don't Fix It

March 12, 2012 - PLA as a replacement of PC? or HDPE? or PP? Are you Nuts?