Polymer Chemistry Basics

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Questions and Answers

What type of catalyst is used in the manufacturing of Teflon?

Base catalyst

Enzyme catalyst

Persulphate catalyst (correct)

Acid catalyst

What is the primary characteristic of polyacrylonitrile?

It can only be used in the form of granules

It is a synthetic fiber used as a wool substitute (correct)

It is a homopolymer used for insulation

It is chemically active and highly corrosive

What does the process of step growth polymerization typically involve?

A single-step reaction leading to instant polymerization

Repetitive condensation reactions between bi-functional units (correct)

The addition of multiple monomers at once

Formation of a linear polymer with no by-products

Which of the following is an example of a condensation polymer?

Terylene (Dacron) Signup and view all the answers

What type of polymer is formed from the polymerization of acrylonitrile?

Homopolymers Signup and view all the answers

What characteristic distinguishes low density polythene from high density polythene?

Low density polythene has a highly branched structure. Signup and view all the answers

Which statement about Teflon is true?

It is resistant to attack by corrosive reagents. Signup and view all the answers

Which monomer is used to obtain polystyrene?

Styrene Signup and view all the answers

What is the primary catalyst used in the production of high density polythene?

Ziegler-Natta catalyst Signup and view all the answers

What process is used to form low density polythene?

Addition polymerization under high pressure Signup and view all the answers

A by-product in step growth polymerization could include which of the following?

Water Signup and view all the answers

At what approximate temperature is high density polythene produced?

333 K to 343 K Signup and view all the answers

What is NOT a common application of low density polythene?

Dustbins Signup and view all the answers

Which property is associated with high density polythene?

High density due to close packing Signup and view all the answers

What is the result of polymerizing ethene with a peroxide initiator under high pressure?

Low density polythene Signup and view all the answers

Which of the following statements about polythene is incorrect?

High density polythene has a branched molecular structure. Signup and view all the answers

What is Dacron fibre primarily known for?

Crease resistance and blending with other fibres Signup and view all the answers

Which reaction is involved in the formation of Phenol-formaldehyde polymers?

Condensation reaction Signup and view all the answers

What type of polymer is Bakelite classified as?

Thermosetting polymer Signup and view all the answers

What is the initial product formed in the reaction of phenol with formaldehyde?

Novolac Signup and view all the answers

Which of the following uses for Bakelite is NOT mentioned?

Crockery production Signup and view all the answers

What happens to Novolac upon heating with formaldehyde?

It undergoes cross-linking to form Bakelite Signup and view all the answers

What is the main application of Melamine-formaldehyde polymer?

Producing unbreakable crockery Signup and view all the answers

Which property does NOT describe Bakelite?

It can be remoulded Signup and view all the answers

What type of polymer is nylon considered to be?

Condensation polymer Signup and view all the answers

Which compound is used in the preparation of nylon 6,6?

Hexamethylenediamine Signup and view all the answers

What characteristic of nylon 6,6 contributes to its high tensile strength?

Hydrogen bonding Signup and view all the answers

At what temperature range is Dacron or Terylene manufactured?

420 to 460 K Signup and view all the answers

Which of the following is a product formed from the condensation of amino acids?

Nylon 6 Signup and view all the answers

What type of fibers does nylon classify as?

Synthetic fibers Signup and view all the answers

What catalytic agents are used in the production of Dacron or Terylene?

Zinc acetate and antimony trioxide Signup and view all the answers

Which of the following applications is associated with nylon 6?

Tyre cords Signup and view all the answers

What is the primary characteristic of copolymers compared to homopolymers?

Copolymers contain multiple units of different monomers. Signup and view all the answers

Which polymer is an example of an elastomeric polymer?

Natural rubber Signup and view all the answers

Which of the following options is classified as a condensation polymer?

Bakelite Signup and view all the answers

What type of polymerisation can be used to create a copolymer?

Both step-growth and chain growth polymerisation Signup and view all the answers

What is the base unit of natural rubber?

Cis-1,4-polyisoprene Signup and view all the answers

What distinguishes copolymers from homopolymers in terms of properties?

Copolymers display varying physical and chemical properties. Signup and view all the answers

What role do 'crosslinks' play in elastomeric polymers like natural rubber?

They help the polymer to return to its original shape. Signup and view all the answers

Which of the following is a product made from butadiene-styrene copolymer?

Cable insulation Signup and view all the answers

Study Notes

Polyamides

Polymers with amide linkages known as nylons are important synthetic fibres.
Nylons result from condensation polymerization of diamines with dicarboxylic acids or amino acids.
Nylon 6,6: Formed from hexamethylenediamine and adipic acid under high pressure and temperature; recognized for high tensile strength due to hydrogen bonding.
Nylon 6: Produced by heating caprolactam with water; used in tyre cords, fabrics, and ropes.

Polyesters

Derived from the polycondensation of dicarboxylic acids and diols.
Dacron (Terylene): Synthesized by heating ethylene glycol with terephthalic acid (420-460 K) using a zinc acetate-antimony trioxide catalyst; known for its crease resistance, used in textiles and as reinforcement in safety materials.

Polythene (Polyethylene)

Linear or branched long-chain molecules that are thermoplastic and soften on heating.
Low Density Polythene (LDP): Formed under high pressure (1000-2000 atm) and temperature (350-570 K) using dioxygen or peroxide as a catalyst; characterized by a highly branched structure; used in insulation and flexible products.
High Density Polythene (HDP): Produced through polymerization in hydrocarbon solvent (333-343 K, 6-7 atm pressure) using Ziegler-Natta catalyst; has a linear structure, more rigid, used in robust products like buckets and bottles.

Specialty Polymers

Polytetrafluoroethene (Teflon): Manufactured by heating tetrafluoroethene under high pressure; highly chemical-resistant; commonly utilized for non-stick surfaces.
Polyacrylonitrile: Formed by the addition polymerization of acrylonitrile with a peroxide catalyst; serves as a wool substitute in commercial fibres.

Condensation Polymerization

Involves repetitive condensation between bifunctional or trifunctional monomeric units, typically resulting in byproduct molecules like water or alcohol.
Examples include the production of Dacron from ethylene glycol and terephthalic acid.

Phenol-Formaldehyde Polymers

Oldest synthetic polymers formed by the condensation of phenol with formaldehyde, requiring acid or base catalysts.
Initial products become novolac, which can be cross-linked with additional formaldehyde to create Bakelite, a thermosetting polymer that is infusible.

Melamine-Formaldehyde Polymer

Created through condensation polymerization of melamine with formaldehyde; utilized in manufacturing unbreakable crockery.

Copolymerization

Involves the polymerization of a mixture of different monomers to form a copolymer, exhibiting properties distinct from homopolymers.
Example: Butadiene-styrene copolymer, known for toughness and used in production of tyres and flooring materials.

Natural Rubber

A natural polymer recognized for elastic properties, classified as an elastomeric polymer.
Derived from rubber latex, mainly obtained from rubber trees in tropical regions.
Structurally consists of isoprene (cis-1,4-polyisoprene); exhibits elasticity due to weak intermolecular forces and minimal cross-linking which enables stretching and retraction.

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Description

This quiz covers the fundamental concepts of polymer chemistry, including the synthesis and properties of polyamides. It specifically addresses the roles of ethylene glycol and terephthalic acid in polyamide production. Test your knowledge on these vital topics in materials science.