Polymerisation Flashcards
describe condensation polymerisation
monomer has two different functional group that can react together
formation of small molecules
describe amino acid compound
amine + carboxylic acid group
amino acid + amino acid forms what bond
peptide/amide
how do you form a polyamide
amine group + carboxylic acid/acylchloride
describe reaction to form nylon 6,6
1,6- diaminohexane and hexanedioic acid
name the examples of polyamides
nylon 6,6
nylon 6
kevlar
why is acyl chloride used instead of acid
more reactive but more expensive
describe formation of nylon 6
not formed from condensation reaction
heated in nitrogen - break ring
describe characteristics of nylon
low density
strong
elasticity
clothing/ropes
describe structure of kevlar
long, linear polymer chains line next to each other in pattern
extensive hydrogen bonding between polymer chains
describe properties of kevlar
strong/flexible/fire resistant/used for bulletproof vest
what is the a-carbon
carbon connected to the hydrogen and functional groups (NH2/COOH)
which groups are non polar
alkyl groups
which groups are polar
alcohol
which groups are electrically charged
carboxylic acid/amine group
what is an amino acid residue
one unit of amino acid
describe proteins
polypeptide chains are unbranched
protein has unique sequence of amino acids - determined by DNA
each protein has specific biological function
definition of primary structure of proteins
sequence of amino acids in polypeptide chain
amino acid determines folding for protein
definition of secondary structure of proteins
regular structure arrangement stabilised by hydrogen bonding between NH and CO
describe in detail secondary structure of proteins
a helix - hydrogen bonds formed parallel in same direction
flexible
R groups stick out
b pleated sheets - hydrogen bonds form between different polypeptide chain
definition of tertiary structure of proteins
further folding of polypeptide chain into 3D shape is stabilised by interactions between R groups
describe in detail tertiary structure
disulfide bridges (strong) made by oxidation reactions with cysteine molecules weak vanderwaals (non polar amino acid residues) weak hydrogen bonds ionic bonds (ionised basic + acidic)
how do we hydrolyse proteins
strong aq.acid/alkalie
products of protein hydrolysis
With excess acid → ammonium salt
With excess alkali → sodium salts
what does DNA stand for
deoxyribose nucleic acid
what makes up DNA and what does it do
deoxyribose sugar phosphate group nitrogen-containing base can make copies of itself genetic code to synthesise proteins
describe the structure of DNA
backbone of alternating sugar and phosphate units
two strands run in opposite directions
bases linked by hydrogen bonds
how is DNA structure stabilised
hydrogen bonding between base pairs and vanderwaals between one pair and another
describe semi conservative replication
hydrogen bonds between base pairs are broken
part of double helix unwinds
nucleotide triphosphates separate chain
enzyme catalyse the polymerisation reaction
how are polyesters made
Carboxylic acid + alcohol → ester + water
how are ester bonds broken
aq. h2so4 in reflux
examples of polyesters
terylene
PLA
how is terylene produced
benzene-1,4 dicarboxylic acid + ethane 1,2-diol
antimony (III) oxide catalyst
280 degrees
what is the structure of lactic acid
HO - CH(CH3)-CO2H
what is PLA used for
biodegradable plastics and starch
describe low density poly(ethene)
non polar chains interact with each other through weak vanderwaals
heavily branched = low density/low mp
describe high density poly(ethene)
straight chains with unbranched polymer chains = stronger/higher mp
what do sulfur bridges in polymer chains do
make rubber more resilient
describe traditional adhesives
organic solvent dissolve polymer that sticks surfaces together
solvent evaporates and solid polymer acts as glue
properties of ester solvent in traditional adhesives
low toxicity
volatile
flammable
describe non solvent based adhesives
water forms siloxane (Si-O) cross link between polymer chains
strong links formed by hydrolysis
what are examples of non solvent base adhesives
SMPs
epoxy resins
superglue
describe properties of SMPs
non toxic
environmentally friendly
set quickly
describe epoxy resins
epoxyethane + diamine
condensation reaction
thermosets = covalent cross links
strong
desribe super glue
addition reaction of monomers initiated by moisture
types of degradable polymers
biodegradable plastics
photodegradable plastics
conducting plastics
describe biodegradable plastics
have small starch granules so it can be decomposed quicker with higher surface area exposed
polyester/amides break down by acid hydrolysis in land fill
describe photodegradable plastics
C=O absorb UV and weaken/break
buried plastics can’t be broken
describe conducting plastics
alternate double/single bonds allows pi bonding to spread down polymer
overlapping p orbitals = delocalised electrons moving down polymer
doping = add iodine to improve electrical conductivity
properties of conducting plastics
won’t corrode
less dense
shapes more easily
used for aeroplanes
how to deduce an addition polymer
need to consist C=C only in backbone
copolymer = more than on unsaturated monomer
how to deduce a condensation polymer
possible functional groups: Amine + carboxylic acid Amine + acyl chloride Carboxylic acid + alcohol Acyl chloride + alcohol links present in backbone