chap4, form 5 Flashcards
definition of polymer
A long chain of molecules consisting of monomers.
2 source of polymer
natural polymer
synthetic polymer
5 example of natural polymer
starch, carbohydrate, protein, fats, natural rubber
4 example of synthetic polymer
terylene, polystyrene, polyethene, nylon
monomer of starch
glucose
monomer of protein
amino acid
monomer of fats
glycerol and fatty acids
monomer of natural rubber
isoprene
what are 3 types of polymer
thermoplastic
thermosetting
elastomer
definition of thermoplastic polymer
Can be repeatedly remoulded by heating, and recycled
definition of thermosetting polymer
Cannot be remoulded after heating
definition of elastomer polymer
Can be stretched, return to original shape (elastic)
properties of thermoplastic polymer
When heated: melt
When cooled: solidify
properties of thermosetting polymer
Disintegrate or burn when heated, x recyclable
properties of elastomer polymer
Has high elasticity properties
3 example of thermoplastic polymer
Polyethene, PVC, nylon
2 example of thermoplastic polymer
Melamine, bakelite
example of elastomer polymer
Polyurethane, (SBR) Styrene-butadiene rubber
what are the 2 types of polymerisation reaction?
addition polymerisation
condensation polymerisation
definition of addition polymerisation?
add or break double bonding
addition polymerisation produces polymer ending with ___
-ene
characteristic of polyethene
durable & strong
use of polyethene
plastic bags, bottle, packaging
characteristic of polypropene
durable
use of polypropene
toys, textile, medical & laboratory apparatus
characteristic of polyvinyl chloride (PVC)
strong & hard
use of polyvinyl chloride (PVC)
Water pipes and electrical insulators
characteristic of polystyrene
light & heat insulator
use of polystyrene
heat insulator, food packaging
how many types of condensation polymerisation are there?
2
what are the 2 types of condensation polymerisation are there?
form terylene
form nylon
condensation polymerisation forms what products?
polymer + water/hydrogen chloride
in formation of terylene, what happens to ethanol & carboxylic acid and how is water formed as a byproduct
ethanol loses one H atom
carboxylic acid loses hydroxyl
the H and OH combine to form H2O
in formation of terylene, what kind of bond is formed?
ester bond
in formation of nylon, what happens to amine & carboxylic acid and what is formed as a byproduct?
amine loses one H atom
carboxylic acid loses one Cl atom
H and Cl combine to form HCl
in formation of nylon, what bonding is formed?
a dipeptide/amide bonding formed
synthetic polymers are ____ and ____, relatively ____, can withstand ____ and __1__ __2__, can withstand ___, ___-_____, easily ____
light and strong cheap corrosion chemical reaction water non-flammable mould to shape
most polymers are not ____, the __1__ __2__ of plastics gives rise to ____ and ____ gases like _____ , ____ and _____ that can cause ___
burning of plastics can also produce ____ that worsens the _____
___1___ __2__ can cause __ of marine creature when _____ enter their ____
____ drains can cause ____
biodegradable
poisonous, acidic gases
carbon monoxide, hydrogen chloride and hydrogen cyanide acid rain
carbon dioxide, greenhouse effect
Marine pollution, death microplastic, food chain
Block , flash floods
r____ polymers : through ___, plastics ____ by ___ them without ___ at ___. the products of this process are then ____ into _____
i_____ b___ polymers: ___ polymers with ____ that can be ____ by ____ (to become _____) or through ____ (______)
Recycling, pyrolysis, decompose, heating, oxygen, 700°C, recycled, new products.
Inventing, biodegradable, Mix, additives, decomposed, bacteria (biodegradable) (photodegradable).
IUPAC name of isoprene
2, methylbut-1,3-diene
polyisoprene is surrounded with ___
negatively charged particles
how does latex remain as liquid?
the negatively charged particles repel each other
use of rubber (latex)
clue they start w/ rubber
rubber gloves. rubber boots, tires, soles of shoes
rubber is a w___ s___ at ___
white, solid, 25 C
rubber is ____ and can be ____ and ____ to original ___ when ____
elastic, stretched, return, shape, released
at ___ temperature, rubber turns ___ and ___
high, soft, sticky
rubber cannot ____ e____
conduct electricity
rubber is easily ____ because the ___ in air react with _____ between ___ atoms
oxidised, oxygen gas, double bond, carbon
rubber reacts easily with ___, ___, ____
acids, alkalis, organic solvents
rubber is ____
clue: we are bulletproof
waterproof
what are the 2 ways for later to coagulate?
natural
artificial
how is latex coagulated naturally?
simple je yah explain lagi
bacteria from air enters rubber and secretes lactic acid containing H+ ions
how is latex coagulated artificially?
simple je yah explain lagi
dilute acid containing H+ ions
describe process of coagulation of latex
the lactic acid/dilute acid containing H+ ion react with negatively charged particles which will neutralise the rubber particles. then the rubber particles collide against each other, breaking the protein membrane surrounding polyisoprene. Polyisoprene will clump together, changing the state of matter from liquid to solid.
latex is more valuable when given in ___
liquid form
to prevent coagulation of latex. what is added
NH4OH (ammonium hydroxide) or aqueous ammonia as it contains OH- ion
how does NH4OH or aqueous ammonia prevent coagulation of latex?
it neutralises the H+ ion produced by bacteria as it contains OH- ions. the protein membrane remains negatively charged and continue to repel each other
ionic equation of NH4OH
NH4OH –> NH4+ + OH-
neutralisation eq that occurs
OH- + H+ –> H2O
Why is strong acid not used in coagulation of latex?
that would cause a sudden drop in pH, leading to irregular coagulation of the latex particles.
what is the best quality of latex ?
sheet rubber
what is the 2nd best quality of latex?
block rubber
what is the lowest quality of latex?
clump rubber
why do rubber tappers have to collect latex before sunrise (7 am)?
(relate to rate of reaction)
As the sun rises, the surrounding temperature increases. Increase in temperature will increase the rate of reaction. Increase in reaction because higher collision frequency and particles vibrate rapidly. rubber particles collide frequently with H+ ion of bacteria.
definition of vulcanisation of rubber
a process of producing rubber that is more elastic and with better quality through the production of cross-links between polymer chains.
what is vulcanisation of rubber
sulphur
3 characteristics of vulcanised rubber
hard, non-sticky, more elastic
vulcanised rubber used in daily life as
car tyre
how is rubber vulcanised?
Adding sulphur compound into latex - forming sulphur link - maintain elasticity of rubber
