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प्रश्न
Distinguish between
Thermoplastic and thermosetting plastic.
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उत्तर
| Thermoplastic polymers | Thermosetting polymers |
| These are formed by addition polymerisation | These are formed by condensation polymerization |
| Generally more expensive than thermosetting | Cost-effective |
| Monomer used in these is generally bifunctional | In this monomer used is tri, tetra or polyfunctional |
| Aesthetically-superior finishes | More difficult to surface finish |
| They are long-chain linear polymer with negligible cross-links | These have three-dimensional network structure with number of cross-links |
| less resistant to high temperatures | More resistant to high temperatures than thermoplastics |
| They have low molecular wt. | They have high molecular wt. |
| They are soft, weak, brittle | They are hard, strong and more brittle |
| Highly recyclable | Cannot be recycled |
| They can be softened and reshaped and reused. | They cannot be softened and reshaped again once again. Highly flexible design |
| High-impact resistance | Low-impact resistance |
| Remoulding/reshaping capabilities | Cannot be remoulded or reshaped |
| Eco-friendly manufacturing | Eco-foe manufacturing |
| e.g.- polyethene, polystyrene, PVC, PVA etc. | e.g.- phenol-formaldehyde, ureaformaldehyde, nylon 6 : 6 etc. |
संबंधित प्रश्न
Explain why plastic containers are favoured for storing food.
Write uses of PVC.
Which measures will you arrange to minimize the environmental problems arising due to non-degradable plastic?
What are the demerits of plastic?
HOTS
The Tamil Nadu Government has banned the use of one-time use throwaway plastics. Why do you think this is important?
Read the following information and convert them into a graph to compare the countries and the amount of plastic they use.
China contributes the highest share - that is around 28%, of the total plastic used globally. Indonesia uses 10%, both the Philippines and Vietnam use 6% each; Thailand uses 3.2%, Egypt 3%, Nigeria 2.7% and South Africa 2%.
PVC (polyvinyl chloride) is a thermoplastic and is used for making toys, chappals, etc. Bakelite is a thermosetting plastic and is used for making electrical switches, handles of various utensils, etc. Can you write the major difference between these two types of plastics?
Which of the following is non–bio degradable?
The used plate is easy to recycle.
Answer the following by rearranging the jumbled letters :
Expanded polystyrene is commercially known as ______.
mthreolco
