Falling Oil Prices and ExxonMobil

I've been preaching for a while about how ExxonMobil is incorrectly blamed for any and all possible problems around the world that can be connected to our modern petroleum-consuming economies. While ExxonMobil may indeed be at fault for many of these accused problems either directly or indirectly, I again want to emphasize that they are a small fish in a large ocean.

Look at the recent price drop in petroleum around the world. ExxonMobil has nothing to do with this, and in fact, the low prices are hurting them. Revenues are dropping, investments are dropping and their stock price is dropping. Is anyone saying ExxonMobil is responsible for the low prices? Or si the blame being put on Saudi Arabia, whose National Oil Company, Saudi Aramco, has the largest reserves in the world, and who isn't cutting production?

People being people, ExxonMobil will again be vilified when prices do increase and their profits follow. No one will blame Saudi Aramco, and our profound, collective ignorance of the true dynamics of the petroleum industry will continue.

Previous Years

January 15, 2013 - Assault with a Deadly Hair Removal Gel

Monkey see, monkey do

Back in November, Dow Chemical was able to reach a truce with their "activist investor" Daniel Loeb of Third Point LLC., by letting Third Point put two of their people on the Dow Chemical Board of Directors. (In a rather intelligent move, Dow Chemical also added 2 additional directors so there are now 14 total. Had Loeb won his proxy fight, his 2 directors would have been 2/10 = 20% of the board. Now they are 2/14 = 14%. It may have been awhile since Dow's CEO was at the bench, but he certainly understands dilution to this day.)

The other large US-based chemical company whose name also starts with with the letter "D" is now in a similar fight with an activist investor, in this case Nelson Peltz and his company Trian Investors. No doubt emboldened by Loeb's (dubious) success, guess what Peltz wants? You got it - he wants to put directors on Dupont's board! Peltz obviously has a little more time on his hands than Loeb does, as Peltz wants to be one of the directors, while Loeb was quite content to let his cohorts have that role.

Dupont's Board is already 14 members and Peltz is running a slate of four candidates. If they all win, they would make up almost 4/14 = 29% of the Board. Or maybe Dupont can copy what Dow did and let Peltz put two on the board while Dupont adds two more, in which case Peltz will only control 2/18 = 11% of the Board. That would be a significant swing.

I've not followed Dupont's business closely, so they may or may not be deserving of a kick in the pants to wake them up, but activist investors never sit well with me. They strike me as too much grandstanding and publicity seeking and not having enough focus on rational thought. Such behavior is typical for politicians. I don't approve of it from either group.

Previous Years

January 14, 2014 - Finally a Commercial Phosphorus Polymer?

January 14, 2010 - A Viscoelastic Surface for People, too!

January 14, 2010 - Recycling Plastics

Kinetics, Thermodynamics and Polymer Phase Transitions

Polymers appear to break many rules of thermodynamics on a regular basis, when in actuality nothing of the sort occurs. I bring this up after reading an article in the Guardian yesterday about glass transitions in polymers that has too many errors to just let slide. I don't think that these errors are acceptable. While explaining the glass transition of polymers can run you afoul of numerous difficulties, The Wall Street Journal did an admirable job a few years back, so I don't think my standards are too high.

Consider this excerpt, which really is logically incoherent:

"Every polymer locks up ...at its own particular temperature, known as the glass transition temperature, usually denoted T_g. This is the temperature at which the chains can no longer move fast enough to respond to any external forces to allow deformation to occur. If you hit the polymer fast with a hammer this means that a higher glass transition temperature is recorded than if you slowly pull on it."

If that last sentence came to you as out of nowhere, or maybe better, as a sudden blow to the head with a hammer, you're not alone. It's quite a non sequitur The discussion starts on T_g as a temperature, but then a hammer enters the picture and that changes everything about that temperature? And how is that change in temperature "recorded" when the hammer comes down? This is horribly unclear but I understand where the author wants to go.

A polymer can act glassy in two entirely different manners. First, it will behave as a glass when it is cooled below its glass transition temperature. But it can also act glassy (and the emphasis here in on "act") even if it is above its T_g when too great a stress is applied too quickly. In this latter case, the polymer strands do not have the time to relax and flow past each other and so they have to stay in place and take the stress without moving - just like a glass. I'm guessing that that is where the "hammer" comes from - a short, sharp blow from a hammer can shatter some polymers like glass. But to suggest that this glasslike behavior "changes" the T_g is entirely incorrect. And it contradicts the first sentence - "Every polymer locks up...at its own particular temperature...."

Then consider this:

"The glass transition temperature is quite different: its value depends on how you measure it. This makes it something of a thermodynamic oddity; it isn�t a true phase transition at all. "

Oh boy, them's fighting words [*]. The glass transition temperature is a true phase transition, but it is a 2^nd-order phase transition, not a first order phase transition such as the boiling of water that the author compares it to.

Measuring any phase transition (1^st- or 2^nd-order) in a polymer takes patience, at least if you want to measure a true equilibrium value. Ideally you need to cool down the sample very slowly so that the polymer chains can relax any internal stresses and reach a true equilibrium configuration. But the cooler you go, the longer it takes since the viscosity of the polymers increase rapidly. And so compromises between cooling speed and data accuracy need to be made. By looking at data from multiple tests, it is possible to extrapolate an equilibrium value which is why we can have tables of glass transition temperatures. Extrapolations like this a very common in science. Think about absolute zero. We've never been able to cool a sample to 0 K, but we still know that the temperature exists and we can extrapolate numerous thermodynamic data to it as well. And so it is with the glass transition temperature.

I stated that patience is need for measuring any phase transition in polymer. For even a 1^st-order phase transition such as melting, the values you record will depend on the heating rate. Because polymers are such poor thermal conductors, measuring the melting transition at higher rates would increase the "thermal lag" between the transition and the applied temperature. Measurements are typically made at 10 ^oC per minute, a completely arbitrary value (since the rate has dimensions, it is arbitrary) that is a compromise between accuracy and measurement rate. If that rate is changed, the temperature of the transition would be reported differently. To requote the article, "...its value depends on how you measure it". No, the values don't vary in this case either. It is an experimental error, nothing more, and results from our impatience in waiting for equilibrium data.

You may have noticed the two main points here both rely on the balance between kinetics and thermodynamics.

• Because of the sometimes slow kinetics polymer have in relaxing internal stresses, they can be glasslike in appearance. This can appear at conditions well removed from the equilibrium glass transition temperature, but it does not mean that the glass transition temperature has changed.
• Because of the slow rate at which polymers conduct heat, measuring any phase transition for a polymer is a compromise between getting the data at a reasonable rate and the accuracy of the data.

[*] Three times in my professional life I have witness arguments get so heated that I thought it would break out into a barehanded brawl. Two of those arguments were over the glass transition and statements just like this.

Previous Years

January 13, 2014 - Still Proposing Changes to the Resin Identification Codes

January 13, 2010 - Race Horses and Rheology

January 13, 2009 - Walking Polymers

Much about Nothing; OR The FDA clears BPA - again

Back November while I was distracted by other matters, the FDA once again found that the current uses of BPA in food packaging are safe:

"FDA�s current perspective, based on its most recent safety assessment, is that BPA is safe at the current levels occurring in foods. Based on FDA�s ongoing safety review of scientific evidence, the available information continues to support the safety of BPA for the currently approved uses in food containers and packaging."

This will not end the debate, but my concerns are not so much on the safety of BPA, but rather on what the alternative will be.

And that is a point that BPA's critics are deafly silent on.

BPA has been used for over 50 years. There are still ongoing investigations about about it and an never ending debate about what risks are acceptable, there are even a greater number of unanswered questions about all of the alternatives, since none of them have been used for anywhere near that time period. Further, the regulatory reality would also be that if BPA is banned and the new alternative is found to be just as bad or even worse than BPA, there will be no going back to BPA, since afterall, it was banned. Imagine the outcry against the agency proposing to un-ban a previously banned substance. Senators Blather, Bluster and Bellyacher would immediately be on TV calling for hearings (the speakers at such hearings would of course largely be movie stars, sports figures and musicians since they have expert opinions on all matters of importance), and Representatives Rep, Publi and Can would be calling to impeach the President (unless it was a Republican president, in which case it would be Representatives Demi and Crat calling for impeachment).

Also keep in mind that this view on the safety of BPA is the same one taken by regulatory agencies in Canada, Europe and elsewhere. It's not just the FDA that is "in the pocket" of the canning manufacturers - that evil cabal has their fingers everywhere.

Previous Years

January 12, 2011 - My Polymer Chemistry Hero

Janauary 12, 2009 - Connections (with apologies to James Burke)

Getting past the dreaded Pay-Per-View firewall

Now that I'm without great access to technical literature, I get to brush up on my skills for getting articles that are normally behind a pay-per-view firewall. I can't get that done on my good looks alone, so I have to be creative.

This morning, for instance, I had a request from someone looking for help with dissolving polyethylene oxide (PEO) in ethanol. I've dissolved it in water plenty of times, but that can actually be difficult because PEO is readily soluble in water at room temperature. Unless you are adding at an extremely slow rate, it will clump up and form "snots" that will never disperse. But if you adjust the temperature, either by adding ice to the water, or by boiling the water (actually 90 ^oC is hot enough), you can dump the PEO pretty quickly. Then let it warm/cool to room temp and away you go. The ice slows down the dissolution rate which prevents clumping, while the hot water is actually not capable of dissolving the PEO - it is merely getting dispersed quite well - so that upon cooling you have a clump free solution.

But back to the literature. I had no idea if the same tricks could work with ethanol, so I googled "PEO ethanol solubility" and this was at the top of the results. From the abstract, the paper looked spot on, but as expected, it was behind the dreaded pay-per-view firewall.

But I didn't let that stop me. I copied the article title into the Google Scholar search bar and - oh happy day - saw this:

Hoop-yeah! A .pdf version is available. That was both quick and easy.

Why go through a firewall when you can quickly do an end run?

I passed all of this onto the requester in short order. And in case you are curious, it appears that the heat dissolution technique will work in ethanol, but when the solution cools the polymer starts to crystallize out creating a paste. That's all the more I'll say at this point, in order to respect the privacy of the requester.



(All of this reminds me that I need to update the "Free Access to Research in the Polymer Literature" page that you can access on the left hand side of the blog.)

Previous Years

January 8, 2010 - Time to Close Up Shop

Weeding-out Engineering Students

Over the recent holiday break, a discussion about "weed-out" courses was hashed out by fellow bloggers Chemjobber, "Just Like Cooking" and Thoreau. So while I may be late to the party, as long as there are incoming freshmen, there will always be "weed-out" classes and so these comments should be just as timeless.

The biggest difference in my discussion however, is that rather than focussing on education future chemists, I'm going to speak to educating future chemical engineers, and there are some pretty big differences. Engineering classes typically don't start until the end of the sophomore year or early junior year. Junior year is pretty late in one's career to face a weed-out class and risk of changing one's major, but that is how it's still done. Keep in mind that at this point, the students have already survived the "weed-out" freshman chemistry class and now have to face their introductory "Mass and Energy Balances" class or something equivalent.

For those unfamiliar with the subject, it is mostly a matter of bookkeeping. You have a piece of equipment that has various mass and energy flows going in and out. The one and only equation you need to know is

"Accumulation = Inflow - Outflow + Generation - Destruction"

You set up some linear equations and solve for the unknowns. There probably are some unit conversions too, but this is all just a matter of keeping the details straight. If a student can't handle this, they are really going to lose it when it comes to doing the same in fluid mechanics. In that subject, they have run similar balances with 3-dimensional, multivariable calculus.

When I was a TA, I never once was told by the prof that we had to cut a certain number of people or reduce the size of the class or hold the students to some arbitrarily high and/or capricious standard(s). It always seemed to me that students self-selected changing their major. And blaming it on a bad prof isn't too likely, as this initial stuff was pretty straightforward and intuitive. It's no different than balancing a reaction. Having a rotten prof for fluid mechanics and heat transfer is an entirely different matter. [*]

This all reminds me of the one episode where the prof in fact actually bent over backwards to pass a student. He was a senior who never did any homework and only came to class for the exams. I personally don't have a problem with such an approach IF the student still does well. But that wasn't case here. The student always had the lowest grade on exams. So come the end of the year, I recommended an F for him. Imagine my surprise to see that shot down. He got a D. The prof justified it by saying the school would be done with the student. He would graduate and never be on this campus or any other again. A Gentleman's D.


[*] I know. Been there, done that. And am still irate at the profs all these years later. And it wasn't just me. The Class of 1984 from Minnesota is the "Lost Class", the one that never provides news items to the Alumni newsletter or donates money. 30 years later and the anger is still there. That's how much a bad prof or two can impact hundreds of students.

Previous Years

January 6, 2014 - How Cold Is It???

January 6, 2012 - Free Access to Articles in the Polymer Literature

January 6, 2010 - Polycarbonate (and BPA and Phosgene)

Time's "Person of the Year" - and Plastics

Over the past couple of holiday weeks, Time Magazine came out with their "Person of the Year" issue. The cover, seen on the right, was all over the newsstands when I was shopping. What hit me the most was that the photo barely showed the person underneath - only their eyes and little bit of skin around the eyes were visible. The rest of the person - covered in plastic.

I've made the point before (1, 2) of how much worse this outbreak would have been without plastics, single-use plastics at that, the favorite whipping boy of anti-plastic environmentalists. I seriously question if many of the people reading this would be alive (including me [*]) and whether the world economy would have collapsed once every nation shut their borders if we didn't have such plastics.

Or perhaps the question is a non-starter, since a world without plastics would lack the ease of travel which leads to the ease of spreading the disease. But in the same vein, I wonder how many lives could have been saved during the Plague had plastics been available. It wouldn't have prevented them all, since germ theory wasn't well understood then, but still, there were enough basic public health practices that plastics could have improved the situation some.

None of this is to take away from the people that still have to don and doff the gear (doffing being the risky part) and they deserve out greatest respect. But there still needs to be some recognition that plastics play a critical role in the fight too. Plastics by themselves won't treat the ill or prevent the spread, the medical professionals need to attend to that, but without plastics, their jobs would go from being hazardous to suicidal.



[*] One of the largest Liberian communities in the US is here in the Twin Cities and many of them have traveled back there during the outbreak, so this city and state were following the outbreak with greater concern than other areas. Further, my father volunteers as an English teacher and many of his students are Liberian immigrants. There's your six degrees of separation.

Previous Years

January 5, 2011 - ANTEC Bound

January 5, 2010 - Amusing Names for Rheology Models