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Polymer manufacturers and designers are naturally interested in how elastic their polymers are, but up to now they have not had a way to accurately predict how stretchy or rigid new polymer designs will be. This is because, whilst a theoretical level of elasticity is calculable, the flaws and defects that are found in real world polymeric molecular chains are an unknown factor that prevents a precise formula being created.

That is until now, for a research team from MiT have created a method to calculate how elastic a new polymer will be; a key discovery that polymer engineers have been trying to make for more than a century. As Jeremiah Johnson, a Professor of Chemistry at MiT and a key player in the research explained, “This is the first time anyone has developed a predictive theory of elasticity in a polymer network, which is something that many have said over the years was impossible to do.”

Previous calculations to predict how flexible a polymer would be were very theoretical, as they did not compute how many of the molecular chains were defective. In theory all of the molecular chains in a polymer bind with another chain, however some of them inevitably bind with themselves to create ‘floppy loops’ that weaken the material.

Seeing that this was the root of a problem, Johnson and his colleague Bradley Olson, an Associate Professor of Chemical Engineering at MiT, came up with a way of measuring the number of defects in a polymer.

A discovery the online journal Phys.Org reports the discovery as follows;

“The researchers designed polymer chains that incorporate at a specific location a chemical bond that can be broken using hydrolysis. Once the polymers link to form a gel, the researchers cleave the bonds and measure the quantity of different types of degradation products.” Developing this research further, the team have made a breakthrough as, “By comparing that measurement with what would be seen in a defect-free material, they can figure out how much of the polymer has formed loops.”

The result is a formula for predicting a polymer’s elasticity. As Anne Trafton explains on the MiT website, “First, they calculated how a single defect would alter the elasticity. This number can then be multiplied by the total number of defects measured, which yields the overall impact on elasticity.”

You can watch the video of MiT’s explanation of the discovery here.

Olsen described the process himself, when he said, “We do one complicated calculation for each type of defect to calculate how it perturbs the structure of the network under deformation, and then we add up all of those to get an adjusted elasticity.”

The process has already been tested out on numerous materials and has held true, proving it to be a far more accurate predictor than the previous methods (known as the affine network theory and the phantom network model), neither of which factored defects into their calculations.

Now the team has published their results in the peer review journal, Science, where the research team reported how, “The results led to a real elastic network theory (RENT) that describes how loop defects affect bulk elasticity. Given knowledge of the loop fractions, RENT provides predictions of the shear elastic modulus.”

The research is already being hailed as a massive step forward in our understanding of polymer dynamics and will be a massive boon to both polymer manufacturers and designers. Something that Sanat Kumar, professor of chemical engineering at Columbia University, who was not part of the research, agreed with when he said, “They have taken an age-old problem and done very clear experiments and developed a very nice theory that moves the field up a whole quantum leap.”

But the researchers have not yet finished their work, as they plan to expand their predictive process to cover other materials, with Olsen stating that, “I think within a few years you’ll see it broaden rapidly to cover more and more types of networks.”

Meanwhile the Phys.org website explains how the researchers, “are also interested in exploring other features of polymers that affect their elasticity and strength, including a property known as entanglement, which occurs when polymer chains are wound around each other like Christmas tree lights without chemically binding to each other.”

But for now polymer traders and plastic producers are looking forward to the improved products that it is hoped will be developed now that much of the guesswork of polymer design has been removed.

As Trafton explains, “This theory could make it much easier for scientists to design materials with a specific elasticity, which is currently more of a trial-and-error process.”

Photo credit: Jose-Luis Olivares/MIT

A very wise man once said that calculating future prices in the chemicals industry is 60% art and 60% science. Whilst this wise man clearly needed some help with his maths, he was right to say how difficult the process is.

To outsiders, trading industrial chemicals may seem like a straight forward business. But to those that know, it is an occupation fraught with challenging logistics and long lead times; complex with economics, politics, psychology and chemistry. It is a world where a deal that does manage to get completed is filled with so much secrecy over pricing that it is difficult to find out the value of a chemical trade made today, let alone six months from now.

When faced with such obstinate problems, it is usually best to consult someone who knows more about the subject that yourself. An expert such as Paulo Moretti, former Purchasing Director at Dow Chemical and a man who understands the important relationship between the value of crude oil and the price of many basic chemicals including ethylene and propylene. He recently wrote in his excellent blog, the following on why the price of crude oil had crashed since its relatively stable high of around $100 per barrel just a few years ago:

“There are competing theories about the reasons for the Crude Oil price decline. Some conspiracy theorists believe OPEC wants to financially restrict Iran and ISIS, which are both financed by oil exports. Others believe that OPEC wants to decrease the global oil inventory so the price will increase easily. My own view is that global oil prices declined in order to delay Shale Gas (mainly in the U.S.) investments and further production.”

If the OPEC factor is the true reason behind lower oil prices, and consequently a major influence in lower Ethylene and Propylene prices, then it is worth noting that these last few years have seen troubling times for many of those oil rich members.

Low oil prices are close to collapsing the economy in Venezuela, (with the IMF declaring 700% inflation), whilst a recent Deloitte report stated that, “Most OPEC countries have little room to manoeuvre because of their reliance on oil revenues to balance national budgets. These include Iran (where oil prices of around $130/bbl are needed to balance the national budget), Venezuela, Iraq and Nigeria. Unlike the Gulf states (Kuwait, for example, requires a price in the mid-$50/bbl to balance its budget), they have no large foreign exchange reserves to fall back on to sustain state expenditure and the oil price collapse has been exacerbated by existing problems such as sanctions, political instability, security and corruption. Nigeria, for example, has been recently forced to raise interest rates and devalue its currency the naira.”

Even mighty Russia is troubled with anti-Ukraine conflict sanctions and desperately needs a higher oil price to ease the burden, with CNN reporting that, “Russia loses $2 billion for every dollar fall in the global oil price.”

Furthermore, if one of the reasons that oil prices are being kept low is to hamper ISIS (who are also heavily dependent on oil for revenue, then that reason may soon be gone, with the new Russian/US/Turkish/Iraqi coalition expected to push the Islamic State out of its Iraqi stronghold and capital in Mosul within the month (click here for BBC report).

Moretti notes that only one oil dependent country can ride the current period of low oil prices without fear, stating, “Saudi Arabia has $741 billion of currency reserves and posted a $15 billion surplus at the end of its last fiscal year. This means that it can run budget deficits for several years without causing major harm to the country’s finances.”

All of which leads him to predict that, “Crude Oil price will reach an average of US$50/BBL in 2016 and US$60/BBL in 2017. Furthermore, if those oil prices hold true, and with Natural Gas around US$2.70/mmBTU, we may predict the following impact on Ethylene and Propylene.

The above predictions are based on statistical correlation analysis over the last 10 years.”

But Moretti is aware of the near infinite number of factors that go to setting a price for global commodities such as ethylene and propylene, and touches on the relationship between the many chemical products when he writes, “Let us be very clear that the prices of Ethylene and Propylene are driven by the feedstock but also by the supply-demand balance of each one, as well as other derivatives. For example, Ethylene pricing depends on demand for middle-distillate products like gasoline, diesel, and heating oil. Additionally, propane pricing represents a ceiling price for Ethane. As result of all these drivers, Ethylene and Propylene prices have presented a delta (Propylene less Ethylene) between -$5 in 2000 to +$20 in 2011. Therefore, the prices may fluctuate much more than shown here.”

Furthermore it is important to factor in what weather forecasters call the ‘Butterfly Effect’. The concept that a butterfly’s wings beating in China today will affect air pressure, impacting the weather in Rome six months from now. A fact that makes predicting the weather and future chemical prices a thankless task, and leads even an expert such as Moretti to be even more cautious in his predictions, stating, “For now, I propose you check my price predictions at the end of 2017 to see if I was right. If not, sorry; I just gave my view.”

You can read more on Moretti’s predictions and theories on pricing strategy and tools here.

Or look into your own crystal ball and predict the Ethylene and Propylene prices of 2017 yourself.

Written Sept 2016

Photo credit: Margie Shapiro

One of the most difficult things about developing a new coating for metal is getting the (organic) paint to stick to the (non-organic) metal. Up until now, coating specialists have used heavy metals, such as iron phosphate, zinc phosphate or chrome to aid this process, but using these substances adds to cost and, if spilt can have a negative effect on the environment.

But now a new coating has been developed that promises to be both hard-wearing on metal and yet is kind on the environment. It is a system which uses a primer based on water and silica, followed by a layer based on polysilicates.

As the industry journal DurabilityandDesign, writes, “First, a base layer of water mixed with silica is sprayed on to the metal, creating a chemical bond with the metal. This not only cleans the metal but also deposits silica onto the surface. This coating protects the metal while also acting as a primer for the second layer, which was designed to bond well to paint.

The second layer contains polysilicates, the basis of which is silicon, reported to be the second-most abundant element in the Earth’s crust. Silicates can be modified to stick to both metals and paints.”

The breakthrough was made at Brock University in Ontario, Canada in cooperation with the business enterprise Vanchem Performance Chemicals, and was led by organic chemist Paul Zelisko, who described the coating as being based simply on water and reactive sand, so that, “If the material happens to get flushed out or it leaks, you’re effectively releasing sand and water into the environment.”

So far, tests on the new coating have shown it to be extremely effective against corrosion, as the Brock University website explains, “When the industry wants to determine whether or not a coating product is effective, the treated metal sheets are put into salt-spray chambers, where a fine mist of salt water is continually sprayed onto the metal until it starts to show signs of corrosion. The industry standard is around one thousand hours, ‘But,’ says Zelisko, ‘our coatings ranged anywhere from 1,800 to 3,000 hours, in some cases almost three times as good as what the industry requires.’”

Vanchem vice president Ian McLeod is hopeful that there will be high demand for the product, as it is part of a trend towards environmentally friendly coatings.

“The industry has switched over to greener technologies; they want to get rid of the heavy metals,” he explains. “Large corporations and companies want to be environmental stewards. They want to be able to say, ‘look at what we’re doing, we’ve replaced the old zinc phosphate technology with a new silane-based technology that doesn’t have any environmental impacts.’”

As well as being eco-friendly, the new coating is expected to be an aid to coating and paint manufacturers who wish to avoid adding heavy metals to their feedstock supply lists. Unfortunately, despite silica being an overwhelmingly abundant resource, the new process has yet to be proven entirely cost effective.

As McLeod states, “the initial price of a ‘green’ coating may be more expensive than a zinc phosphate one. But, factoring in environmental disposal, maintenance and other costs associated with non-green coatings, companies could save money in the long run.”

So for now it seems the jury is out on the true impact this coating will have on the market, as it will depend greatly on a paint supplier‘s long-term plan and the consumers’ willingness to pay extra for the eco-label. Of course future changes in coating feedstock prices, such as a price increase in heavy metals relative to silica prices, will make all the difference to this coating’s success in the marketplace.

Failing that it would be down to changes in protective coating legislation or paint manufacturing, or a shift in customer attitudes towards saving the planet. And for that you must ask yourself, “Would you pay more to ensure your coating is ‘green’?”

Photo credit: Brock University / Cathy Majtenyi