Intro to Polymers PT 1&2 Flashcards
Why are polymers important?
- Replace materials like wood, aluminum, steel and glass
- They are organic materials of low density (1 g/cm^3)
- Versatility of synthesis-processing-property relationships
- Raw materials and processing are cost effective and disposal is practical
What are 5 unique features of polymeric materials?
- Synthesis (step and chain polymerization)
- Average molecular weight and molecular weight distribution
- Type of bonding (covalent and van der Waals + hydrogen bonding)
- Semicrystalline morphology (Amorphous and crystalline)
- Viscoelasticity (temperature and time dependence)
Name some originally natural polymers?
Wood, cotton, leather, rubber, wool and silk
What elements are polymers made up of?
Hydrocarbons (hydrogen and carbon)
What is it called when carbon is singly bonded to four other atoms?
Saturated hydrocarbons
of carbons is 1-4, what is the state and the use?
gas, cooking
of carbons is 5-11, what is the state and the use?
liquid, gasoline
of carbons is 9-16, what is the state and the use?
liquid, kerosene
of carbons is 16-25, what is the state and the use?
liquid, oil and grease
of carbons is 25-50, what is the state and the use?
solid, paraffin wax
of carbons is >10,000, what is the state and the use?
tough solid, bottles
What are unsaturated hydrocarbons?
Double and triple bonds – which can be somewhat unstable and form new bonds
Where are double bonds found in?
Ethylene or ethene
Where are triple bonds found in?
Acetylene or ethyne
What is isomerism?
Two compounds with the same chemical formula but different structures
What is polyethylene?
A long chain hydrocarbon
What is this molecular structure?
Linear
What is this molecular structure?
Branched
What is this molecular structure?
Cross-linked
What is this molecular structure?
Network
