Chemistry

Polymers and Plastics

1,228 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

Which of the following statements is/are false?

  1. Natural rubber is a chain growth polymer.

  2. Bakelite is prepared by copolymerization of phenol with formaldehyde.

  3. Polyvinyl acetate is a thermoplastic.

  4. Caprolactam is obtained by Beckmann rearrangement of acetophenone oxime.

  5. Bubble gum contains styrene-butadiene rubber.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

This option is correct,  because caprolactam is obtained by Beckmann rearrangement of cyclohexanone oxime.

Multiple choice

Which one of the following is an example of a composite rocket propellant?

  1. Polyurethane, ammonium perchlorate and Al

  2. Polyurethane, ammonium chloride and Mg

  3. Polyurethane, ammonium hydroxide and Al

  4. All of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Composite solid propellants contain fuel (aluminum powder), oxidizer (ammonium perchlorate), and binder (polyurethane) in a heterogeneous mixture. Ammonium chloride is not a proper oxidizer, and ammonium hydroxide is not a solid oxidizer.

Multiple choice

Neoprene, a synthetic rubber is made from

  1. dichloroethane

  2. 2-chlorobutadieme

  3. carboxy-methyl cellulose

  4. methanol
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Neoprene (polychloroprene) is a synthetic rubber produced through polymerization of 2-chlorobutadiene (chloroprene). This monomer contains both chlorine and diene functional groups, giving neoprene its excellent resistance to oil, chemicals, and weathering.

Multiple choice

In vulcanization process rubber is hardened by adding

  1. nitrogen

  2. silicon

  3. sulphur

  4. alcohol
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Vulcanization is the process of hardening rubber by heating it with sulphur. The sulphur forms cross-links between rubber polymer chains, transforming sticky natural rubber into durable, elastic material used for tires, shoes, and various industrial applications. Charles Goodyear discovered this in 1839.

Multiple choice

Which of the following properties make thermosetting plastics differ from thermoplastics?

  1. Thermoplastics can be deformed easily, but thermosetting cannot.

  2. Thermoplastics have higher tensile strength than thermosetting plastics.

  3. Thermoplastics are more flexible than thermosetting plastics.

  4. Thermoplastics are more durable than thermosetting plastics.

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Both thermosetting plastics and thermoplastics have almost the same tensile strength and durability. Both thermosetting and thermoplastics are non-biodegradable but thermoplastics can be recycled but thermo setting plastics cannot. The main difference between the two is that thermosetting plastics once set cannot be moulded again, but thermoplastic can be remoulded on heating. 

Multiple choice

Which of the following is not a thermosetting plastic?

  1. Melamine

  2. Polyvinyl chloride

  3. Bakelite

  4. Both (a) and (c)
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Polyvinyl chloride can change its shape on heating. But we know that thermosetting plastic does not change its shape on heating. So, polyvinyl chloride cannot be an example of thermosetting plastic. 

Multiple choice

Which of the following properties do thermoplastics not possess?

  1. Thermoplastics are easily deformed on heating

  2. Thermoplastics can be recycled and reused again.

  3. Thermoplastics cannot be softened by heating once they are moulded.

  4. Thermoplastics can be coloured and rolled into sheets.

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

 Thermoplastics are the plastics, which are easy to recycle and reuse as they change their shape on heating. Also they can be dyed to give various colours so, the statement 3 is the characteristic property, which is not     possessed by thermoplastics. 

Multiple choice

Thermosetting plastics cannot be softened by heating because _____.

  1. they are cross linked polymers with hydrogen bonds between each chain

  2. they are linear chains of polymers

  3. they are large cross linked molecules with strong covalent bonds between the atoms along each chains

  4. they are large cross linked molecules with strong electrovalent bonds between the atoms along each chain
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

 Thermosetting plastics are formed by sharing of electrons. It means that they form a covalent bond between their sub units. Covalent bonds of  their sub-units are very strong. This makes thermosetting plastic a strong cross linked molecule, which becomes hard to break, even by heating. 

Multiple choice

What are thermoplastics?

  1. The ones which can be deformed easily.

  2. The ones which do not become soft on heating.

  3. The ones which do not melt on heating.

  4. The ones which are hard and rigid.

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Thermoplastics melt down easily on heating and can be moulded to give various shapes. It means that they can be deformed easily and are not rigid. 

Multiple choice

Which of the following is a fire proof plastic?

  1. Teflon

  2. Melamine

  3. Polythene

  4. Polystyrene

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

 Teflon is non reactive towards oil. Plastics and polystyrene melt down, if they catch fire. Melamine is resistant to fire and therefore, it is known as fire proof plastic. 

Multiple choice

Why are electric plugs, switches and plug boards made of thermosetting plastics?

  1. Because thermosetting plastics are not biodegradable.

  2. Because thermosetting plastics cannot be deformed, and these are poor conductors of heat and electricity.

  3. Because thermosetting plastics have high tensile strength.

  4. Because thermosetting plastics have light weight, lower price, and these can be handled easily.

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Electric plugs, switches etc. should be made of such materials, which neither allow the heat nor the current to pass through. Also, they should not melt down on heating. Thermosetting plastics possess these properties. Therefore, they are used for the same purpose. 

Multiple choice

Which of the following is not a polymer?

  1. Nylon

  2. Acrylic

  3. Amino acid

  4. Silk
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Polymer is a compound having a high molecular mass and is made up of many small repeating units called monomers. Nylon, acrylic and silk  are polymers. However, amino acids are monomers of proteins.

Multiple choice

What is the meaning of Greek word polymer?

  1. poly : small : mer : part

  2. poly : large : mer : unit

  3. poly : many : mer : part/unit

  4. poly : big; mer : part/unit

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The word polymer is derived from two Greek words - poly and mer. 'Poly' means 'many' and 'mer' means 'part/unit'. A polymer is made of many small repeating units called monomers.