9.5

One way to differentiate between polymers is to look at their functional groups - distinctive arrangements of atoms that impart characteristic chemical properties to the molecules that contain them.

9.5

Condensation Polymers

Examples Natural: starch, wool, silk, proteinsSynthetic: nylon, kevlar, and ABS

Formation of PET

9.7

Composition of municipal solid waste:

100 billion pounds of plastic is produced in the U.S. each year- much of this ends up in landfills.

Recycling

9.8

Example of closed loop recycling

Ever heard of aluminum dross?

Recycling

9.8

Aluminum dross is a by-product of the primary and secondary aluminum industries

White drossBlack drossSalt cake

None are on the EPAs Hazardous Materials List

So in the U.S. it has been co-disposed along side of municipal solid waste for many years. Two Billion Tons are buried each year.

Al skimming toolScrap + white dross

Recycling: Al

9.8

Aluminum dross

“Mount Rumke” before “Mount Rumke” after dross exposure to water

Recycling: Al

9.8

Aluminum dross

Fe2O3 (or sometimes Fe3O4) + Al → Al2O3 + molten iron (Fe) + A LOT OF HEAT

2 Al + 6 H2O → 2 Al(OH)3 + 3 H2 + heat

AlN + 3 H2O → Al(OH)3 + NH3

The chemistry behind the troubles