HS2339 Week 2 Asyn_Structure of polymers 1 & 2 Flashcards
Polymer formation
- Join through Covalent Bonding (eg ethylene into polyethylene), called addition, using free radicals
- ## or condensation, where an OH and H are removed to create water, and form an ester link
Diagram of addition and condensation
Diagram of different names for different polymers
Polymer structures: attraction between chains and cross linking
What is vulcanisation of rubber?
Rubber is treated by humans, to change its properties, to make it stiffer with addition of crosslinks
- uses sulphur and heat to break open bonds
Polymer families and properties
Diagram of hydrocarbons and possible isomers
isomer: Any of two or more substances that have the same molecular formula but differ in their connectivity or spatial arrangement of atoms
Table of functional groups on polymers
Table of functional groups and examples of compounds
Definition of secondary bonding
Diagram of dispersion forces (van der waals)
Diagram of electronegativity in atoms
Diagram of Secondary hydrogen bonding
- the hydrogen’s electron is pulled strongly towards one way ie chlorine or oxygen, causing a permanent positive charge (these are permanent dipoles)
- strong attraction (called a bond even through it isn’t really)
How alcohol is dissolved in water
- water has a hydrogen bond
- as does methanol
- alcohol dissolves in water
Secondary bonding as seen in the properties of materials eg wood
- make molecules align and sit together
- eg the walls of wood make of cellulose, a long carbohydrate chain
- align through hydrogen bonding
alkanes, ketones, alcohols
- alkane- the only secondary forces are dispersion forces
- has a strong dipole in the O-H bond (hydrogen bond)- Ethanol
- ketone
alkane chains, change in properties as chain increases
- the longer the chains, the more dispersion forces present
- ## With the longer chains eg pentane becoming liquids, there is enough attraction between molecules due to van der waals, to make them liquids
Examples of polarities in polymer chains
How structure, functionality and secondary bonding influences physical properties
Cumulative effect of secondary attractions between molecules
bonding and forces influencing packing of molecules
tacticity of chains, and how it influences the crystalline or amorphous nature of materials
Summery of secondary bonding
- stablising structure
How cohesive energy impacts viscosity and volatility
Volatility- how easily a substances vapourises
How secondary forces influence miscibility and solubility
diagram of crystalline and amorphous structures
In polymer chemistry, a copolymer is a polymer derived from more than one species of monomer.
Different packing structures of polymers