Josie Colbert



My green chemistry project was about using an already green product and recycling it after its useful life to make another product. What were these two products???? A PLA cup and a soap scum cleaner!! PLA is a fancy term for a plastic that is created from polymers that are natural starches. A polymer is simply something that is made up the same units bonded together. A PLA natural starch polymer can come from rice, corn, and potatoes.
Instead of having this green product traditionally recycled I found a lab procedure done by other college students that through a simple chemical process turned a discarded piece of PLA into something useful. My project was simplified from the original to meet my personal goals.

Background information about plastics
  • The world produces 200 billion pounds of plastics each year
  • The degradation period of plastics are longer than their useful life
  • The degradation period can range from 500 to 1000 years
  • Most plastics are made from polyethylene (HDPE), polyethylene terephthalate (PET), and polystyrene (PS)
  • These traditional plastics are cheap and easy to produce
  • They are produced from petroleum feedstock
  • Petroleum is a nonrenewable resource

PLA (poly lactic acid) information

  • PLA is greener choice compared to traditional polymers (plastics)
  • PLA commercial production was abandoned in the past because it was too expensive, but because of new advances the process had become more cost effective
  • A leading PLA produced is Cargill Dow Natureworks
  • Natureworks' PLA production process uses 20-50% less fossil fuels then traditional plastic manufacturers
  • Natureworks' PLA uses corn to to create their polymer
  • Corn is a cheap renewable resource
  • Natureworks' PLA is also biodegradable
  • Natureworks' PLA is now being used for some products by major companies such as Coca-Cola and Sony


PLA cup

250 ml Erlenmeyer flask

Sodium Hydroxide pellets


Magnetic stir bar

Stirring/hot plate



pH meter

Graduated cylinder


Shred PLA and measure out 5 grams and put in 250ml flask

Measure 6 grams of sodium hydroxide (NaOH) pellets (this will make the pH go up) Add to flask
Measure 50 ml of alcohol and 50 ml of water and add to flask


Put a magnetic stirrer bar in flask

Put flask on hot plate and adjust the heat so the solution is boiling and turn on stirrer

Place a watch glass over flask so the vapors stay in flask and the volume of the solution does not decrease (* if solution does decrease in volume add more alcohol 10 ml at a time)


Leave on hot plate for 1 hour

Dissolve 1 capsule of phydrion buffers 4.00±0.02@25°C in 100 ml of water to test the calibration of the pH meter which you will later use in the solution on the hot plate


Dissolve 1 capsule of phydrion buffers 7.00±0.02@25°C in 100 ml of water to test calibration as well


After one hour take flask off heat and place in ice bath

Place pH meter in solution and take reading. (The goal should be 3.8)


Continue to add 50 % HCl acid to filtered solution make the pH meter read 3.8 (fill eye dropper with HCl acid and add only a couple drops at a time)

Set up a filter over another flask and pour in solution to remove any residual particulate matter
Now use the solution to remove soap scum on house hold items


Sources I used and sources where you can get more info!

Chemistry Dictionary. NetAccess Systems Inc. 15 Nov. 2011 <>.

Cups to Cleaners, Trash to Treasure: Converting a PLA cup to LA soap an Introductory Organic Chemistry Laboratory.

University of Oregon. 15 Oct. 2011. <>.

How It’s Made. NatureWorks LLC. 2011. 29 Nov. 2011.


Jennifer N. Boice, Christina M. King, Carol Higgenbotham, Richard W. Gurney. Molecular Recycling: Application of the Twelve Principles of Green Chemistry in the Diversion of Post-Consumer Poly Lactic Acid Waste. Journal of Materials Education. 2008. 10 Nov. 2011. 30 (5-6), 257-280.

All photos and videos taken by Josie Colbert

A special thanks to my Aunt Bev for her supervision on the lab portion of my project and to Portsmouth Christian Academy for letting me use their lab