Macromolecules Flashcards
(21 cards)
What are macromolecules ?
A very large molecule made from many small repeat units joined together by covalent bonds
What are polymers?
Type of long-chain macromolecules linked together by many small repeat units joined together by covalent bonds
Molecules made up of many small repeated units called monomers
What is polymerisation?
A chemical process by which monomers react and a polymer is produced by joining together a large number of small repeating units to form a polymer
How is a polymer formed?
By linking together many small repeating units to form one large molecule. It is formed when monomers react under certain conditions ( eg high temp and pressure) aka polymerisation
What is addition polymerisation?
Addition polymerisation occurs when unsaturated monomers react and join together to form one large molecule (polymer) as the only product without losing any molecules or atoms.
What are the conditions for the monomers to become addition polymers?
C=C double bonds ; unsaturated monomer
What are the functions of poly(ethene)
Can be made into:
Plastic film for wrapping fresh vegetables and meat
Plastic bottles and bags
Plastic buckets and pipes
How is poly(ethene) formed?
The carbon-carbon double bonds of the alkene molecules(monomers) are overcome at high temperature and pressure in the presence of a catalyst
This forms open units that can join together
Each monomer forms single bonds with two other monomers
And eventually they join to form a giant molecule called a polymer
What are the advantages of synthetic polymers?
Can be readily moulded
Unreactive, durable and come in a variety of colours
Relatively cheap
What are the disadvantages of using synthetic polymers?
Non-biodegradable ( cannot be broken down by bacteria in the ground ) and hence can pollute the environment
A fire hazard because plastics burn to produce toxic products
What are condensation polymers?
Polymers made from 2 different types of monomers each with 2 functional groups
What is condensation polymerisation?
Condensation polymerisation occurs when monomers react and covalently join together to form a large molecule ( polymer) with the removal of small molecules like water as by-products
What is nylon?
A polyamide
What is terylene?
A polyester
What are the advantages and disadvantages of using terylene instead of cotton?
Polyester lasts longer and keeps its shape better
But is less comfortable than cotton
What are the uses of nylon?
Making ropes , bags , pulleys and fishing lines.
It can be woven into clothes to make nylon tents , parachutes and raincoats
What are the advantages of using plastic over other materials?
Relatively cheap
Easily moulded into various shapes
Light, tough and waterproof
Durable - resistant to decay, rusting and chemical attack
What are the disadvantages of using plastics?
Plastics are non-biodegradable and cannot be broken down into simpler substances naturally by bacteria in the soil This results in land pollution . As they are unable to be decomposed quickly, they take up a lot of land space for a long time resulting in the increase in the amount of built-up waste Burning of plastic results in the release of poisonous gas that causes air pollution Plastic wastes that are disposed into the sea harms aquatic life. Animals choke from eating plastics Greenhouse gases (methane) are produced when plastics decompose
What polymer is formed from diol and diacid monomers? What linkage
Polyesters; terylene ; Ester linkage
What polymer is created by dicarboxylic acid and Diamine monomers?
Polyamide; nylon ; amide linkages (O=C-N-H)
What are the characteristics of nylon
Strong yet light
Can be stretched without breaking
