Chemistry

Polymers and Plastics

1,227 Questions

Polymers and plastics questions explore the properties, synthesis, and applications of various synthetic and natural polymers. Key topics include biodegradable plastics, vulcanization, and polymer nanocomposites. These concepts are frequently tested in science and engineering competitive exams.

Biodegradable plasticsPolymer nanocompositesVulcanization of rubberPolymer molecular weightAsphalt binders

Polymers and Plastics Questions

Multiple choice chemistry polymer polymers of commercial importance some commercially important polymers condensation polymers

Which of the following polymers shows a sharp melting point?

  1. Butyl rubber

  2. Polystyrene

  3. Bakelite

  4. Nylon-6,6
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Crystalline polymers exhibit sharp melting points because their chains are arranged in an ordered structure. Polystyrene, specifically isotactic polystyrene, can show crystalline properties, whereas rubbers and cross-linked polymers like Bakelite are amorphous or thermoset.

Multiple choice chemistry polymer polymers of commercial importance some commercially important polymers condensation polymers

The commercial name of poly(methyl methacrylate) is:

  1. Lucite

  2. Plexiglas

  3. Perspex

  4. All the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Poly(methyl methacrylate) (PMMA) is a transparent thermoplastic often used in sheet form as a lightweight or shatter-resistant alternative to soda-lime glass. It has since been sold under many different names, including Acrylite, Lucite, Plexiglas and Perspex.

Option D is correct.

Multiple choice chemistry polymer polymers of commercial importance some commercially important polymers condensation polymers

Fomaldehyde is the starting material for the manufacture of :

  1. backelite

  2. caprolactam

  3. D.D.T

  4. rayon
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Formaldehyde is the starting material for the manufacture of Bakelite (phenol-formaldehyde resin), which was the first synthetic plastic. Caprolactam is used for Nylon-6, DDT is a pesticide made from chloral and trichloroethane, and rayon is made from cellulose. Note: There is a typo in option A ("backelite" should be "Bakelite").

Multiple choice chemistry polymer polymers of commercial importance some commercially important polymers condensation polymers

Which polymer among the following polymers does NOT soften on heating?

  1. Bakelite

  2. Polythene

  3. Polystyrene

  4. PVC
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Thermoplastics:
A plastic material, which can be repeatedly melted-molded again and again by simple heating, is called a thermoplastic. Thermoplastics become soft and moldable on heating. They can then be recast in different shapes and cooled. On cooling the thermoplastic material hardens.

Polyethylene, polystyrene and PVC are examples.

Thermosetting plastics:
A plastic material, which cannot be repeatedly melted-molded again, is called a thermosetting plastic.thermosetting plastics do not become soft on heating and they do not change their shape on heating.
Bakelite is one example of a thermosetting plastic.
Multiple choice chemistry polymer polymers of commercial importance some commercially important polymers condensation polymers

Which of the following is a monomer of teflon?

  1. Difluoroethane

  2. Trifluoroethane

  3. Tetrafluoroethane

  4. None of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Teflon is an addition polymer of tetrafluoroethylene.

$\underset {\text{tetrafluoroethylene}}{ n{ F } _{ 2 }C=C{ F } _{ 2 } } \xrightarrow [ \text{Pressure}]{ \text{Heat}} \underset { \text{teflon} }{ -{ ({ F } _{ 2 }C-C{ F } _{ 2 })- } _{ n } } $
It is used to make non-sticky utensils.