What is the structural difference between HDP and LDP? How does the structure account for different behaviour and nature, hence the use of a polymer?
LDP consists of highly branched chain molecules. Due to branching, the molecules do not pack well and therefore, it has low density (0.92 g cm 3) and low melting point. LDP is transparent of moderate tensile strength and high toughness. It is chemically inert.
HDP consists of linear chains and therefore, the molecules can closely pack in space. Therefore, it has high density (0.97 g cm 3) and high melting point. It is quite hard, tougher and has greater tensile strength than LDP.
Which type of biomolecules have some structural similarity with synthetic polyamides? What is this similarity?
What is a biodegradable polymer ? Give an example of a biodegradable aliphatic polyester.
Write the monomers used for gettingThe following polymers:
(i) Polyvinylchloride
(ii) Teflon (iii) Bakelite
Why should the monomers used in addition polymerisation through free radical pathway be very pure?
Which of the following polymers are condensation polymers?
(a) Bakelite (b) Teflon
(c) Butyl rubber (d) Melamine formaldehyde resin
Which of the following polymers are thermoplastic?
(a) Teflon (b) Natural rubber (c) Neoprene (d) Polystyrene
In the following questions, a statement of Assertion (A) followed by a statement of
Reason (R) is given. Choose the correct answer out of the following choices:
(a) Assertion and Reason both are correct statements but Reason is not the correct explanation of Assertion.
(b) Assertion and Reason both are correct statements and Reason is the correct explanation of Assertion.
(c) Both Assertion and Reason are false.
(d) Assertion is correct but Reason is false.
(e) Assertion is false but Reason is correct.
Assertion (A): Rayon is a semi-synthetic polymer and is taken as a better choice than cotton fabric.
Reason (R): Mechanical and aesthetic properties of cellulose can be improved by acetylation.
Classify the following as addition and condensation polymers:
Terylene, Bakelite, Polyvinyl chloride,Polythene
Out of chain growth polymerisation and step growth polymerisation, in which type will you place the following.
Assertion (A): Network polymers are thermosetting.
Reason (R): Network polymers have high molecular mass.
Which of the following polymers can have strong intermolecular forces?
(a) Nylon (b) Polystyrene (c) Rubber (d) Polyester
What is the structural difference between HDP and LDP? How does the structure account for different behaviour and nature, hence the use of a polymer?
Assertion (A): Olefinic monomers undergo addition polymerization.
Reason (R): Polymerisation of vinyl chloride is initiated by peroxides/ persulphates.
Assertion (A): Olefinic monomers undergo addition polymerization.
Reason (R): Polymerisation of vinyl chloride is initiated by peroxides/ persulphates.
Which of the following polymers are used as fibre?
(a) Polytetrafluoroethane (b) Poly chloroprene
(c) Nylon (d) Terylene
Name the polymers used in laminated sheets and give the name of monomeric units involved in its formation.
Assertion (A): For making rubber synthetically, isoprene molecules are polymerised.
i Reason (R): Neoprene (a polymer of chloroprene) is a synthetic rubber.
Vulcanisation makes rubber .
(a) more-elastic (b) soluble in inorganic solvent
(c) crystalline (d) more stiff
Synthetic polymers do not degrade in the environment for a long time. How can biodegradable synthetic polymers be made. Differentiate between biopolymers and biodegradable polymers and give examples of each type.
Assertion (A): Most of the synthetic polymers are not biodegradable.
Reason (R): Polymerisation process induces toxic character in organic molecules.
Assertion (A): Polyamides are best used as fibres because of high tensile strength.
Reason (R): Strong intermolecular forces (like hydrogen bonding within polyamides) lead to close packing of chains and increase the crystalline character, hence, provide high tensile strength to polymers.
Assertion (A): Network polymers are thermosetting.
Reason (R): Network polymers have high molecular mass.
Write the name and structure of one of the common initiators used in free radical addition polymerisation.
What is the role of benzoyl peroxide in addition polymerization of alkenes? Explain its mode of action with the help of an example.
Match the polymers given in Column I with the type of linkage present in them given in Column II.
