L-
15
(POLYMER)
Q.1 (a) write
the names of the polymer used for making unbreakable crockery.
(b) Write
the reaction of preparation of neoprene
(c) Arrange
the following polymers in decreasing order of intermolecular forces.
Nylon-6,6, PVC and
Natural rubber.
Q.2 Write the names and structures of the
monomers of following polymers.
(a)
Buna-S (b) Nylon-6,6 (c) Neoprene
Q.3 Write the names and structures of the
monomers of following polymers.
(a)
Teflon (b) Polystyrene (c) Dacron
Q.4 Write the names and structures of the
monomers of following polymers.
(a)
Polythene (b) Bakelite (c) Nylon-6
Q.5 Is
a homopolymer or a copolymer?
Q.6 Define thermoplastic and
thermosettiplepolymers.Give one example of each.
Q.7 What is a biodegradable polymers?Give one
example of biodegradable aliphatic polyester.
Q.8 Write the names of the monomer of the
given polymer
---[HN-(CH2)6-NH-CO-(CH2)4-CO]n-
Q.9 Arrange the following polymers in
decreasing order of intermolecular forces.
(a) Nylon
6,6 , Buna-S , Polythene
(b) PVC
, Nylon-6 , Neoprene
ANSWERS
A.1 (a) Monomers
of the polymers are melamine and formaldehyde.
(b)
(c) nylon-6,6>Natural
rubber>PVC
A.2 (a) Buna-S
Monomer: 1,3-butadiene CH2=CH-CH=CH2
Styrene CH2=CH-C6H5
(b) Neoprene
Momomer: chloroprene CH2=CH-C(Cl)=CH2
(c) Nylon-6,6
Monomer: Hexamethylenediamine H2N-(CH2)6-NH2
Adipic acid HOOC-(CH2)4-COOH
A.3 (a) Teflon
Monomer: Teraflouroethene CF2=CF2
(b) polystyrene
Monomer: styrene CH2=CH-C6H5
(c) Dacron
Monomers: Ethylene glycol HO-CH2CH2-OH
Teraphthalic
acid
A.4 (a) Polythene
Monomer: ethane CH2=CH2
(b) Bakelite
Monomers: Phenol formaldehyde
(c) Nylon-6
Monomer: Caprolactum
A.5 Homopolymer
A.6 Thermplastic
polymers: These polymers are
capable of repeatedly softening on heating and hardening on cooling.Example-Polythene
and Polystyrene.
Thermosetting
polymers: These polymers on
heating undergo extensive cross linking in moulds again become infusible.These
can not be reused.Example-bakelite and urea formaldehyde resins.
A.7 Polymers which disintegrate by themselves
over a period of time due to environment degradation by microorganisms are
called biodegradable polymers.Examples-PHBV
A.8 Monomer units are hexamethylenediamine and
adipic acid.
A.9 (a) Buna-S
< Polythene< Nylon 6,6 (b) Neoprene <PVC < Nylon-6
MLL
1-What
are polymers.
2-What
is polymerization.
3-Giving
suitable example differentiate between thermosetting and
Thermoplastic polymers.
4-what
is initiator in addition polymerization.
5-Define
vulcanization.
ANSWERS
1-Polymer
is a large size molecule consist of many small units.
2-When a large number of small molecules
(monomers) join togater by covalent bonds
a large molecule is formed called polymer ,this process is called
polymerization.
3- i)Thermosetting polymers
cannot be melted but thermoplastic melts on heating.
ii)Thermosetting have extensive cross links but thermoplastic
have few cross links.
4-Benzoyl
peroxide is used as initiator.
5-Heating
of rubber with sulphur is called vulcanization.
HOTS QUESTIONS
1.Why the vulcanized rubber is hard .
2.How
the novolac is converted to Bakelite .
3. How decron is obtained , What is its use.
4-Classify
ihe following in to fibre, elastomer ,thermoplastic and thermosetting.
Nylon 6,6.,Bakelite,buna –s and polythene.
5-What
is difference between copolymer and homopolymer.
6-Could
a copolymer be formed in both addition and condensation polymerization or not?
Explain with example.
7-
Write chemical name of ( Ziegler Natta catalyst).
8-
What is PMMA ? What are the use of PMMA.
9-
Explain the difference between Buna -S and Buna- N.
ANSWER
1-Due
to the presence of sulphide linkage between polymer chain the
Vulcanized ruber is hard.
2-Novolac on heating with excess of formaldehyde forms
Bakelite.
3-Ethylene
glycol and terepthalic acid on condensation polymerization
Forms Dacron which is used in fabrics, seat
belts ,boat sails.
4-Nylon
66 –fibre ,Bakelite-thermosetting, Buna S- elastomer, Polythene
-thermoplastic.
5-Homopolymer
made up of same monomeric species like PVC , polythene.
Copolymer made up of two different
monomeric species like buna –S.
6- Yes, copolymer could be formed in both
addition and condensation polymerization. Bakelite is a condensation polymer
and Buna-s is a addition polymer.
7- It is Triethylaluminium and titanium
8-
PMMA is poly methyl methacrylate is a polymer of Methylmethacrylate. It is used
for making lenses , transparent objects, domes and skylights, aircrafts windows
,protective coatings etc.
9-
Buna –S is a copolymer of 1,3 butadiene whereas Buna –N is a copolymer of 1,3
Butadiene and acrylo nitrile (CH2=CH-CN)
Value
based Questions
Q.1 At
a sweet shop, Raju bought some sweets. He requested the sales boy to put the
sweet box in a polythene bag .The sales boy refused to do so. Instead, he kept
the sweet box in a paper bag .After reading the above passage, answer the
following questions.
(i) Why the sales boy refuse to put the sweet box in a
polythene bag?
(ii) As a student of chemistry, why would you
advocate the use of paper bag instead of polythene bags?
Which value is promoted through the use
of paper bag?
(iii) Suggest two activities to promote these values.
Ans: (i) Polythene is banned because it is
non-biodegradable.
(ii)Use of polythene bag results in
pollution.
Value: Reducing environmental
pollution
(iii) Use of mass media to educate people.
Q.2 Pooja and Nancy were happy to know that the
polymer are of different types, some of them were used to make cups for hot
drinks, and others to make non stick cook wares , and some to make unbreakable
cups and plates. Name the polymers and monomers for each kind above.
Ans:
For hot drinks polystyrene is used
which is a polymer of styrene. C6H5-CH=CH2
For non stick cook wares Teflon is used which is poly tetra
fiuoroethane
Polymers of tetra fluoro ethane
n CF2 =CF2 ------------à [- CF2- CF2-]n
For
unbreakable cups and plates Melamine is used which is a polymer of Urea and
Formaldehyde.
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