Question

11.
Answer the following long questions
114 = 12
5) Explain the differences between Thermoplastics and Thermosetting plastics.
6) "Avoid the plastics as far as possible" comment on this advice.
7) Explain about Rayon fabric.
PART – B
Complete the following M.C.Q's
5x 1 = 5
1) Which fibre is known as fake sheep
a) Rayon
b) Nylon
c) Acrylic
d) Polyster
2)
represents
)
a) PET
b]Рp c) PVC
d) HDPE
3) Name a synthetic fibre which is polyamide ( )
a) Rayon
b) Nylon c) Acrylic
d) Polyster
4) Polymers are made up of small units called
)
Q Layers
b) Molecules
c) cells
d) Monomers.
5) Wood pulp is used to make
(
a plastic
b) wool c) jute
d) Rayon​

Answer 1

Answer:

Explanation:

5)  Thermoplastic:

*Thermoplastic can be synthesized by the process called addition polymerization.

*Thermoplastic is processed by injection moulding, extrusion process, blow moulding, thermoforming process, and rotational moulding.

*Thermoplastics have secondary bonds between molecular chains.

*Thermoplastics have low melting points and low tensile strength.

*Thermoplastic is lower in molecular weight, compared to thermosetting plastic.

  Thermosetting Plastic:

*Thermosetting plastics are synthesized by condensation polymerization.

*Thermosetting Plastic is processed by compression moulding, reaction injection moulding.

*Thermosetting plastics have primary bonds between molecular chains and held together by strong cross-links.

*Thermosetting plastics have high melting points and tensile strength.

*Thermosetting Plastic is high in molecular weight.

6) Avoid the use of plastics as far as possible. Plastics are non-biodegradable materials. So use of plastics is harmful for our environment. The plastics cannot be finally disposed off. They cannot be burnt as when burnt, they release poisonous gases. Plastic bags thrown in the garbage dump are swallowed by animals like cows. These bags choke their respiratory system and can even prove fatal. Therefore, we should avoid plastics as far as possible.

7) Rayon is a versatile fiber and is widely claimed to have the same comfort properties as natural fibers, although the drape and slipperiness of rayon textiles are often more like nylon. It can imitate the feel and texture of silk, wool, cotton and linen. The fibers are easily dyed in a wide range of colors.

MCQ

1) Acrylic fibre.

2)

3) Nylon .

4) Monomers.

5) Rayon​.

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