Plasticizers in Polymers: They make your new car smell…like a new car

As much as we love polymers and all the amazing things you can use them for, we have to admit that many polymers wouldn’t be wonderful at all without the addition of plasticizers.

These commonplace additives impart vital flexibility to numerous products made of plastics and polymers. Plasticizers are why the hose on your dryer bends without breaking (so you can cram it into that tiny little space in the downstairs powder room) and why the aroma inside a new car is entirely different from the aroma inside that 10-year-old beater your college kid drives around.

Plasticizers do their job by acting as a kind of “lubricant” between segments of polymer chains. Without the plasticizer, those chains of molecules would sit on top of each other as rigidly as uncooked spaghetti in a box. Mix in just the right plasticizer and the chains can move freely, like cooked pasta that you’ve topped with a nice olive oil.

Many different materials use plasticizers — PVC, rubber, plastics and so on. In fact, the discovery of plasticizers pretty much made the polymer industry possible. Without a plasticizer, most polymers would just be too brittle and rigid to be useful. If plasticizers didn’t exist, many of the everyday items you rely on — from the rubber soles of your work shoes to the flexible comb you carry in your purse — simply wouldn’t be possible. Virtually any plastic or polymer item you can think of has a plasticizer added to it, and often more than one.

More chemicals than we care to count here are now used as plasticizers, but we can break down the major families plasticizers fall into.

• Phthalates are used in PVC cables, films, coatings, adhesives and certain plastics that need flexibility.
• Dicarbonates are also used in PVC when the application needs to work in low temperatures.
• Phosphates add flame-retardant qualities.
• Fatty acid esters impart flexibility to rubber and vinyl.

Of course the plasticizer a manufacturer uses in a polymer really depends on a number of factors, including what the material will be used for, the physical characteristics desired, the performance needed and the plasticizer’s compatibility with the other compounds in the polymer.

You can imagine that plasticizer problems could totally derail a product, and more than one client has come to us with a polymer or plastic that just wasn’t moving or working the way it should. When a material is proving to be inflexible or faulty in some other way that affects performance, we know to take a look at the plasticizer. There is also concern over the safety of some plasticizers such as Bisphenol A (BPA) which has been linked to negative health effects in children.

The ability to conduct plasticizer testing is a key component of our consumer products testing services. Embrittlement testing is one way we can determine if a plasticizer has leached from a polymer, causing a material to behave in an unexpected and undesired way. Leaching is one of the most common challenges in working with plasticizers. When a plasticizer leaches from a polymer, the material can become rigid and breakable, and product contamination could occur from the leached material, which is not a good thing. In fact, the only nice thing we can say about plasticizer leaching is that it’s what creates that new-car smell!