"Liquid Wood" a Contender To Replace Plastic

Ostracus recommends a Christian Science Monitor piece on the 40-year quest to find a replacement for non-biodegradable plastic. One candidate, written off 20 years back but now developed to the point of practicality, is a formulation based on the lignin found in wood. And it turns out there is another strong environmental reason to put lignin to use in this way: burning it, which is its common fate today, releases the carbon dioxide that trees had sequestered. "Almost 40 years ago, American scientists took their first steps in a quest to break the world's dependence on plastics. But in those four decades, plastic products have become so cheap and durable that not even the forces of nature seem able to stop them. A soupy expanse of plastic waste — too tough for bacteria to break down — now covers an estimated 1 million square miles of the Pacific Ocean. ...[R]esearchers started hunting for a substitute for plastic's main ingredient, petroleum. They wanted something renewable, biodegradable, and abundant enough to be inexpensive."

Comments

Re:Lignin used to be the same way

[fuzzyfuzzyfungus]

There are already bacteria that can attack certain plastics(using an enzyme appropriately called "nylonase". Fairly quick work for a chemical that didn't exist until 1935. Shockingly enough, team creationism doesn't approve).

The trouble, though, is those situations where plastics are destroying some part of the ecosystem far faster than organisms can evolve to clean them up. In the Great Pacific Garbage patch, for instance, the plastic is entering the food chain at an impressive clip and annhilating seabird populations. I'm sure the bacteria will have something figured out within a couple of centuries; but they might not have all that much company when they do.

The crucial thing is the lignin content

[Aviation Pete]

As the article carefully states, even Arboform uses only 50% lignin (yes, I *did* RTFA). The rest is made up of rather expensive "additives" - one crucial ingredient being Ecoflex, a synthetic (= oil-based) polymer which is needed to reduce the extreme brittleness of genuine lignin.

Two hopes spelled out in the articles will never materialize:
- it will never be as cheap as oil-based plastics are today, and
- it will never be able to replace most of the current oil-based plastics due to it's poor mechanical properties (unless we reduce the lignin content even further).