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 chemistry man made materials environmental impact: plastics plastic plastic plastic waste garbage in, garbage out

Plastic is a polymer consisting of:

  1. synthetic monomers

  2. semi-synthetic monomers

  3. natural monomers

  4. both a and b
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Plastic is a material consisting of synthetic or semi-synthetic organics that can be moulded into solid objects of diverse shapes. Plastics are typically organic polymers of high molecular mass, but they often contain other substances. They are usually synthetic, most commonly derived from petrochemicals, but many are partially natural.

Multiple choice chemistry man made materials environmental impact: plastics plastic plastic plastic waste garbage in, garbage out

Which plastic is called a fire proof plastic?

  1. Melamine

  2. Bakelite

  3. Teflon

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

Melamine is poor conductor of heat and resists fire. Most of the synthetic fibres are poor conductors of heat and electricity. However, melamine is used as a coating on the uniforms of firemen as they are flame resistant.

Multiple choice chemistry man made materials environmental impact: plastics plastic plastic plastic waste garbage in, garbage out

Which of the following statement is true about thermosetting plastic?

  1. It undergoes irreversible change during curing

  2. It can melt and take shape only once

  3. It cannot be recycled

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

Thermosetting plastics contain polymers that cross-link together during the curing process to form an irreversible chemical bond. It can't be recycled. The cross-linking process eliminates the risk of the product remelting when heat is applied, making thermosetting ideal for high-heat applications such as electronics and appliances.

Multiple choice chemistry man made materials environmental impact: plastics plastic plastic plastic waste garbage in, garbage out

The world's first fully synthetic plastic was:

  1. Polystyrene

  2. Nylon

  3. Bakelite

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

The world's first fully synthetic plastic was bakelite, invented in New York in 1907 by Leo Baekeland who coined the term 'plastics'. Bakelite is made from carbolic acid (phenol) and formaldehyde and is referred to as a phenolic resin. Bakelite was the first thermosetting plastic.


Hence, the correct option is $C$

Multiple choice chemistry man made materials environmental impact: plastics plastic plastic plastic waste garbage in, garbage out

Bakelite is an example of ___.

  1. elastomer

  2. fibre

  3. thermoplastic

  4. thermosetting polymer
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A thermosetting plastic, also known as a thermoset, is a polymer material that irreversibly cures. The cure may be induced by heat, generally above $200^o C$ $(392\ F)$, through a chemical reaction or a suitable irradiation.
$Bakelite$ is one example of this type.

Multiple choice chemistry man made materials environmental impact: plastics plastic plastic plastic waste garbage in, garbage out

Polystyrene and PVC are thermoplastics.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Polymer of styrene and vinyl chloride (polystyrene and PVC)  can be repeatedly melted and re-molded into new products and are 100% recyclable. 


Therefore they are examples of thermoplastic. Other examples of thermoplastics include polythene (PE), polypropylene (PP), nylons, etc.

Therefore, option A is correct.

Multiple choice chemistry man made materials environmental impact: plastics plastic plastic plastic waste garbage in, garbage out

Consider the following statements-


I. weakest intermolecular forces are present in elastomers.

II. Fibers possess a crystalline nature.


III. Ionic bonds are present in thermoplastic polymers.

Select the correct option from the following:

  1. I and II

  2. II and III

  3. I and III

  4. I,II and III
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Elastomers are rubber like solid polymers in which polymer chains are hold together by weakest intermolecular forces.
Eg : Natural rubber
Fibers are thread-like polymers & can be woven into fabrics. They possess high tensile strength & are crystalline in nature.
Eg ; Nylon $6,6$.

Hence, the correct option is A.
Multiple choice chemistry man made materials environmental impact: plastics plastic plastic plastic waste garbage in, garbage out

Thermosetting plastics cannot be softened by heating because:

  1. they are cross linked polymers with hydrogen bonds b/w each other.

  2. they are linear chains of polymers

  3. they are large cross-linked molecules with strong covalent bonds b/w the atoms along each chains

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

Thermosetting polymers are formed from monomers of viscous state which changes irreversibly on heating into an infusible insoluble polymer. They have high crosslinks due to which they are rigid.

Multiple choice chemistry man made materials environmental impact: plastics plastic plastic plastic waste garbage in, garbage out

Which of the following properties of plastic make it most convenient to use?

  1. It is non-reactive

  2. Light, strong and durable

  3. Easily remouldable

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

Plastics are non-reactive at room temperature and others are highly reactive.

Because of lower density than metals, plastic is light, strong and durable so can be molded in different shapes and sizes easily.
So all the options are correct, all are properties of plastic.

Option D is correct answer.

Multiple choice chemistry man made materials environmental impact: plastics plastic plastic plastic waste garbage in, garbage out

Which one among the following is a thermosetting plastic?

  1. PVC

  2. PVA

  3. Bakelite

  4. Perspex
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Bakelite is another name of phenol formaldehyde which is a thermosetting plastic so bakelite is a thermosetting plastic.

Plastic which has cross-linked (3D) structure and is generally made by the condensation polymerization method is called thermosetting plastic. It can't be reused once it is processed.

Multiple choice chemistry man made materials environmental impact: plastics plastic plastic plastic waste garbage in, garbage out

Which of the following is not correct regarding terylene ?

  1. Condensation polymer

  2. Synthetic fibre

  3. Step-growth polymer

  4. Known as dacron

  5. Thermosetting plastic
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Terylene is a synthetic polymer formed by the condensation polymerization reaction of terephthalic acid and ethylene glycol with the release of a methanol molecule. 


It forms by a step-growth polymerization mechanism in which a bi-functional or multifunctional monomer react to form the first dimer, then trimer, longer oligomer and eventually long-chain polymers. 

It is also called as Dacron and is a thermoplastic, which can be remelted time and again without producing any change.

Multiple choice chemistry man made materials environmental impact: plastics plastic plastic plastic waste garbage in, garbage out

Which of the following is a property of plastic?

  1. Flame resistant

  2. Non-corrosive

  3. Mouldable

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

The properties of the plastics are as follow:

  • They can be easily molded.
  • They are non-corrosive.
  • They are flame resistant.
  • They are a bad conductor of electricity.
Thus all the properties that are given in the options are properties of plastic.

Multiple choice chemistry man made materials environmental impact: plastics plastic plastic plastic waste garbage in, garbage out

Statement: The articles made of thermoplastics can be recycled whereas the articles made of thermosetting plastics cannot be recycled.


State whether the given statement is true or false.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
The intermolecular forces in thermoplastics are weaker while the intermolecular forces in thermosetting plastics are stronger. The thermosetting plastics cannot be moulded on heating. Thus the articles made of thermoplastics can be recycled whereas the articles made of thermosetting plastics cannot be recycled.

Hence, the given statement is $\text{true}$