Karteikarten
3.7 Polymers
Karten in diesem Stapel (13)
- 1Condensation Polymerspolyamides. polyesters and polypeptides
involves 2 different types of monomer, each with at least 2 functional groups that react to form a link. Each link->molecule of water lost (condensation) - 2Dicarboxylic acids and diaminespolyamides
carboxyl group of the dicarboxylic acid reacts with the amino group of the diamine to form amide links. As the functional groups are at each end of the molecule long chains can form - 3nylon 6,6made from 1,6 diaminohexane and hexandioic acid to make clothing, carpet, parachutes
- 4kevlar1,4 diaminobenzene and benzene 1,4 dicarboxylic acid to make vests, boat construction, lightweight sports equipment
- 5Dicarboxylic acids and diolspolyesters
carboxyl group of the dicarboxylic acid reacts with the hydroxyl group of the diol to form ester links. Polymers joined by ester links are called polyesters - 6Terylene (PET)formed from benzene 1,4, dicarboxylic acide and ethane1,2-diol and used in plastic bottles, clothing, sheets and sails
- 7Hydrolysis produces the original monomerscondensation can be reversed by hydrolysis (addition of water)
- 8Condensation polymers contain polar bondsstronger that addition polymers because they are made of chains containing polar bonds (C-N, C-O) so as well as vdw forces there will be permanent dipole-dipole forces and hydrogen bonds between the polymer chains
- 9Disposal of polymers- polyalkenesadditional polymers are made of non-polar carbon chains making them chemically inert (undreactive)- nonbiodegradable
- 10disposal of polymers- condensationpolar bonds meaning that they are open to attacks by nucleophiles. They can be broken down by hydrolysis and may be biodegradable. However, slow process.
- 11Waste plastics can be buriedlandfill is used when
-difficult to separate from other waster
-not in sufficient quantities to make separation financially worthwhile
-too difficult to technically recycle
landfill is cheap, easy method
however-
requires land, releases methane (greenhouse gas), leaks contaminate water supplies - 12waste plastics can be burned and the heat used to generate electricitythe process must be controlled to reduce the release of toxic gases- waste gases are past through scrubbers that neutralise gases such as HCL.
however,
gases such as CO2 still contribute to the greenhouse effect - 13waste plastics can be recylcedsort the plastics
-polypropene can be melted and remoulded
-plastics can be cracked into monomers and used to make more plastics and chemicals
pros
-reduces landfill
-saves raw materials which is important because oil is non-renewable
-cost of recycling is lower than making plastics from scratch
-less CO2 emission than burning
cons
-technically difficult
-collecting, sorting and processing is more expensive than burning or landfill
-can't remake the plastic you had to start with
-easily contaminated
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- Beschreibung
- A-Level Organic Chemistry Karteikarten am 3.7 Polymers, erstellt von nicola Goodship am 16/04/2017.
- Erstellt von
- nicola Goodship
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