Chemists Sweeten Plastics For Faster Diodegradation

Makarand writes "Nature has an online article describing attempts of chemists to create tweaked versions polythene, polystyrene and polypropylene that would rapidly biodegrade in a landfill in the presence of soil bacteria. Their technique adds sugars to the polymer chains, like pendants on a necklace, sweetening them in the process and making them palatable to soil bacteria. Less than 3% of the final plastic would be sugar. However, soil bacteria open the chains when they feed on the sugar kicking off the decay process."

Comments

Re:That's great, but...

[i_am_nitrogen]

From the article (emphasis added):
Digambar Gokhale and colleagues at the National Chemical Laboratory in Pune mix the styrene subunits of polystyrene with small amounts of another substance that provides a chemical hook for sucrose or glucose pieces. They then add sugars to the styrene chains like pendants on a necklace.

It does say what kind of sugar: sucrose or glucose.

Re:Plastics and, no, IN you

[AJWM]

Have I missed something?

Apparently.

It doesn't break down into smaller pieces of plastic (well, it does, but that's a first step). The polystyrene chain is broken into smaller units as the bacteria attack the linked sugars. Those smaller units can then be broken down directly by the bacteria.

Most plastics are poly-hydrocarbons (although stuff like PVC and teflon throw chlorine or fluorine atoms into the mix). Depolymerize them and you get hydrocarbons, which all sorts of bacteria find yummy (depending on the specific hydrocarbon -- but styrene and ethylene both occur in nature (styrene in strawberries, coffee, etc, and ethylene is a chemical trigger produced by and recognized by fruits to hasten the ripening process.)