|Concepts||polymer synthesis by addition and condensation, polymer structure-property relationships, social and cultural implications of polymers|
|Keywords||plastics, addition polymerization, radical, condensation polymerization, amide bond, carbonyl group, electrical insulator, thermoplastic, thermoset, crystallization zone, Wallace Carothers, glass transition temperature, recycling, design for environment (DFE)|
|Chemical Substances||polyester, poly(ethylene terephthalate) (PET), silicone, nylon, polyurethane, norbornene, isoprene, Bakelite|
|Applications||polypropylene in lithium ion batteries, soda bottles and fabrics, electrical insulators, recycling and packaging|
Before starting this session, you should be familiar with:
The next segment on biochemistry (Sessions 30 through 32) builds upon these introductory polymers sessions.
After completing this session, you should be able to:
- Define, compare and contrast the two forms of polymer synthesis.
- Summarize the key properties of polymers that determine their suitability for various applications.
- Explain the relationship between polymer structure and material properties, for instance the effect of crystallization zones on strength and transparency.
- Describe some factors that affect the recyclability of polymers.
|[PB-OC] 28, "Synthetic Polymers."||Addition and condensation synthesis; addition (chain growth) and condensation (step growth) polymers; stereochemistry; dienes and rubber; copolymers; structure-property relationships|
|[JS] 13.1, "Polymerization."||Polymer form as it relates to synthesis; example of collagen|
|[JS] 13.2, "Structural Features of Polymers."||Polymer structure as it relates to synthesis; example of rubber vulcanization|
This session focuses on polymer synthesis, the relationships between polymer structure and properties, and the cultural implications of polymers.
The two forms of polymer synthesis (addition and condensation) are described in terms of processes, resulting chemical structures and properties, and example materials. Factors affecting recyclability are described, along with defining thermoplastic and thermoset characteristics. Crystallization zones are presented as a means for controlling a polymer's mechanical performance.
Prof. Sadoway summarizes the properties of polymers as follows:
- Electrically insulating
- Transparent to visible light (amorphous material) vs. opaque
- Chemically inert
- Strong covalent bonds (thus good for packaging)
- Low density
- Solid at room temperature
Polymers have had significant impact on society. The economic and performance improvements introduced by polymer-based substitute materials have transformed many aspects of modern daily life, and led to entirely new products. The class discussion ranges from early 20th century inventions (e.g. nylon, Bakelite), to the late 1960s fascination with plastics, to present-day concerns about recycling and human health impacts.
[JS] Chapter 13, Sample Problems 13.1 and 13.4
For Further Study
Brown, D. E. Inventing Modern America: From the Microwave to the Mouse. Cambridge, MA: MIT Press, 2001. ISBN: 9780262523493. [Companion website]
Carothers, W.H. Collected Papers of Wallace Hume Carothers on High Polymeric Substances. New York, NY: Interscience Publishers, 1940. ISBN: 9781406759259. [Download or view complete work from Internet Archive]
Other OCW and OER Content
|Polymer Basics, The Glass Transition in Polymers, Crystallinity in Polymers||DoITPoMS||Undergraduate|
|3.063 Polymer Physics||MIT OpenCourseWare||Undergraduate (elective)|
|3.064 Polymer Engineering||MIT OpenCourseWare||Undergraduate (elective)|
|10.467 Polymer Science Laboratory||MIT OpenCourseWare||Undergraduate (elective) / Graduate|
|10.569 Synthesis of Polymers||MIT OpenCourseWare||Graduate|
|Introduction to Polymers||OpenUniversity UK||Masters|