Flashcards
Chemistry Polymers
Cards in this deck (35)
- 1Define a polymersA repeating chain of organic monomer units joined together by bonds
- 2Which two monomer pairs can be reacted to form polyesters?-A dioic acid and diol
OR
-Hydroxycarboxylic acids x2 - 3What are the polymers that react to form polyamides?-Dioic acids and diamine
-Dioic acids have two COOHs on either side
-Diamines have two NHs on either side
-They form PEPTIDE bonds! YES! JUST LIKE AN AMINO ACID - 4What do the numbers in nylon names tell you?The number of carbons in each monomer
The first number is for the DIAMINE
-The second is for the DICOOH - 5What are the two polyamindes?-Nylon and Kevlar
- 6Why are plastics so good to us?-Easy to make
-Easy to colour
-Easy to store
-Easy to ship
-Easy to tailor - 7What are the two types of polymers?-Addition and condensation polymers
-(If you said polyesters and poyamides you can have half a mark; yes only half because they are technically the same type; condensation) - 8Briefly outline addition polymers-This is when ALKENES (they have a double bond) react together and JOIN up
-No by-products are formed - 9What happens during condensation polymerisation?-This is when two monomers form a bond via the loss of SMALL MOLECULES like H20 AND HCl
- 10Name the two types of condensation polymersPolyester and Polyamide
- 11State and explain what molecule is lost in the formation of polyesters-Well, think it through:
-Ester bonds have to be made
-How are esters made? Well, when COOH and OH react in a condensation reaction
-Hey ho! doesnt that lose water? - 12What polymer could you form with lactic acid? (HINT: Lactic acid has the structural formula of CH3CH(OH)COOH)-Well, lactic acid is a hydroxycarboxylic acid so it can react with itself in a condensation reaction
-Water will be lost from OH and COOH thus forming an ester bond - 13How can condensation polymers be broken down?-Hydrolysis via acid and base catalysts
Acid---> Dioic and diol formed
-Base---> Diol and negative dioic acid which reacts with cation to form a dicarboxylate salt - 14What needs to be able to happen for polymerisation to occur?-The monomers need to be able to join to other polymers at both sides
- 15How do you name addition polymers?Put the poly suffix in front of the monomer name
- 16What are the two ways of forming polyamines?-React diols and dioic acids
-React two amino acids together - 17What bonds break during esterification?-The CO in the COOH and the OH in the OH
-The whole of the OH comes from COOH and just one H comes from the OH - 18TOP TIPDon't include hydrogens in monomer units
- 19*Insert PET REACTION8**
- 20What polymer is formed when benzene-1,4 dicarboxylic acid and 1,2-ethanediol?-PET: Polyethylene Terephthalate
- 21Why do we need to add acid or base catalysts to hydrolyse polyesters?Because reacting it with just water would be too slow
- 22State the difference between a repeat unit and a monomerA repeat unit is the smallest sequence that is repeated
-A monomer is the units that join together to form repeat units
So when they say identify the smallest repeat unit, this can include more than one monomer - 23TOP TIPWhen identifying a repeat unit, you need to know when to cut it off:
-Start from anywhere on the chain
-Keep going until you get to where you started
-Now DON'T include that extra bit, where you got to the begining again - 24TOP TIPIt helps if you draw the reacting groups on the same kind of plane, just so you can see what is reacting
-So if you gotta flip the molecule around, so be it! - 25State 3 properties of Polylactic acid1. Can be photodigradable as C=O absorbs radiation
2.Can be broken down to FORM CO2 and H20
3.They are also renewable!! - 26What can polylactic acid be used for-Female hygiene products
-Disposable nappies
-Food packaging - 27TOP TIPPlease please pleaaaaase remember the "n" when writing monomers/ shorthand polymers...most of the class wont remember this but you will! ;)
- 28How can you find the monomer from an addition polymer?-Find the repeating unit
-Then add a double bond - 29Which polymers hydrolyse the easiest? Condensation or addition?Addition will not hydrolyse as easily as condensation. This is because addition polymers are unreactive (because the double bond has become saturated) and therefore, do not react readily with water
- 30REMEMBER!Polyester hydrolysis likes alkaline conditions
Polyamides like acidic - 31TOP TIPWhen hydrolysing an polyamide, you will always get a salt
-Whether it is a diamine salt or dicarboxylate salt, that depends on what you choose as your catalyst - 32Hydrolysis of polyestersWith an acid, this is the slow reaction
You will form a dioic acid and a diol
With an alkali
You get a dioic acid and diol, but then the dioic acid reacts with the base to form a disalt and diol - 33Compare and contrast addition and condensation reaction-Similarities; both include an addition step
-They both form polymers
Differences; - A doesnt lose a molecule but C does
-A is resistant to hydrolysis but C isnt
-A is usually non polar, C is
-A isnt biodegradable, C is
-Conditions of A are a lot higher than conditions of C - 34State 3 ways in which modern scientist are beginning to manipulating polymers and their properties1. Change the length size
2. Change the structure/ type of functional group, to alter cross linking
3. Add in pigments and stuff - 35—
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- A level Chemistry Flashcards on Chemistry Polymers, created by Sparkle Shine on 02/12/2017.
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