Basic Polymer Chemistry

CAST January 28, 2005

Presenters

Jon Valasek• St. Marks School of Texas• Dallas• valasekj@smtexas.org

Debbie Goodwin• Chillicothe High School• Chillicothe, MO• nywin@hotmail.com

Polymer Ambassadors

www.polymerambassadors.org

Mission Statement: The Polymer Ambassadors, with resources from educational, industrial, and professional societies, promote polymer education with teachers, students, and community audiences.

Materials Science Teacher Camps

• Sponsored by ASM International Foundation

• http://www.asminternational.org

• Click on “Foundation” tab

• Click on “Materials Camp” tab

• One week in the summer

• No cost

MST Summer Camps

• Albuquerque, NM Eldorado High School June 12 - 16• Ann Arbor, MI U of Michigan July 17 - 21• Calgary, Canada S Alberta Institute Tech August 21 - 25• Charlotte/Monroe Wingate University June 19 - 23• College Park, MD U of Maryland June 27 - 30• Columbus, OH Ohio State University TBA• Dallas, TX University of Texas July 17 - 21• Denver, CO Colorado School of Mines June 26 - 30• Edmonds, WA Edmonds Community College July 17 - 21• Edmonton, Canada University of Alberta July 24 - 28• Gainesville, FL U of Florida June 26 - 30• Houston, TX U of Houston June 26 - 30• Long Beach, CA California State University July 10 - 14• Piscataway, NJ Rutgers University August 7 - 11• Toronto, Canada University of Toronto August 14 – 16• Youngstown, OH Youngstown State University July 17 - 21

Polymers

• Poly – many • Mer - parts

• Long chain molecules made of many smaller repeating units

Classification

• Natural vs. Synthetic• Type of Polymerization

– Addition– Condensation

• Response to Heat– Thermoplastics– Thermosets

Where do polymers come from

• Natural gas – Linked together by polymerization

• Start with C2H4

Carbon Chains and Boiling Temperatures• Petroleum gas - used for heating, cooking, making plastics

– small alkanes (1 to 4 carbon atoms) – commonly known by the names methane, ethane, propane, butane – boiling range = less than 104 degrees Fahrenheit / 40 degrees Celsius – often liquified under pressure to create LPG (liquified petroleum gas)

• Gasoline - motor fuel – liquid – mix of alkanes and cycloalkanes (5 to 12 carbon atoms) – boiling range = 104 to 401 degrees Fahrenheit / 40 to 205 degrees Celsius

• Kerosene - fuel for jet engines and tractors; starting material for making other products – liquid – mix of alkanes (10 to 18 carbons) and aromatics – boiling range = 350 to 617 degrees Fahrenheit / 175 to 325 degrees Celsius

• Gas oil or Diesel distillate - used for diesel fuel and heating oil; starting material for making other products

– liquid – alkanes containing 12 or more carbon atoms – boiling range = 482 to 662 degrees Fahrenheit / 250 to 350 degrees Celsius

• Lubricating oil - used for motor oil, grease, other lubricants – liquid – long chain (20 to 50 carbon atoms) alkanes, cycloalkanes, aromatics – boiling range = 572 to 700 degrees Fahrenheit / 300 to 370 degrees Celsius

• Heavy gas or Fuel oil - used for industrial fuel; starting material for making other products – liquid – long chain (20 to 70 carbon atoms) alkanes, cycloalkanes, aromatics – boiling range = 700 to 1112 degrees Fahrenheit / 370 to 600 degrees Celsius

• Residuals - coke, asphalt, tar, waxes; starting material for making other products – solid – multiple-ringed compounds with 70 or more carbon atoms – boiling range = greater than 1112 degrees Fahrenheit / 600 degrees Celsius

Chain Lengths

• Beaded chain

• 10,000 carbon atoms – typical polyethylene molecule

Polymerization – Making Chains

Addition polymerization

• Connecting monomers without producing a by-product

• Usually involves breaking a double bond

• Requires an initiator

• Hand-holding simulation chain reaction

HDPE vs. LDPE

• Chains• Density• Crystalline vs. amorphous

Polymerization – Making Chains

Condensation Polymerization• Method of forming molecules

between 2 different monomers • A smaller molecule is also formed as

a by-product• Also known as a step reaction • Example – PETE • Nylon demo

Holding chains together

• covalent bonds – stronger – ex. rubber

• intermolecular forces – weaker – ex. slime

• entanglement – ex. HDPE – – (analogy: 50 pieces of yarn – each 6 feet

long – jumble and wad them up – throw them down in a pile on the ground – try to pull out one piece – what happens???)

Slime

• 4% Polyvinyl alcohol solution

• Add different amounts of 4% borax solution to 50 mL of PVA solution2% 4%8%12%20%

Slime

• Analyze and compare – Viscosity (ability to flow)– Coolness (evaporative cooling)– Elasticity (return to shape after stress)– Plasticity (retains new shape after

stress)

Polyvinyl Alcohol

• Math – % evaporation – Viscosity – Temperature change

• Hospital – Laundry bags

• Industry – Mold release

Additional Labs & Demos

• Sodium alginate snakes• Gak• Latex balls• Happy/sad balls• Others…………….