Which catalyst is utilized in the low-pressure synthesis of High-Density Polythene (HDP) at 333-343 K and 6-7 atmospheres of pressure?
Answer and explanation
Correct answer: C. Ziegler-Natta catalyst (Triethylaluminium and Titanium tetrachloride, (C2H5)3Al + TiCl4)
- Step 1: Low-Density Polythene (LDP) is produced under extreme conditions (, ) using a peroxide initiator via a free-radical mechanism, resulting in a highly branched, low-density structure.
- Step 2: High-Density Polythene (HDP) is synthesized under mild conditions (, ) via coordination polymerization.
- Step 3: This reaction is catalyzed by the Ziegler-Natta catalyst, which consists of triethylaluminium and titanium tetrachloride: .
- Step 4: The resulting polymer consists of linear unbranched chains that pack closely together, giving high density, high tensile strength, and high melting points (used for buckets, pipes, and crates).
Answer
Ziegler-Natta catalyst (Triethylaluminium and Titanium tetrachloride, (C2H5)3Al + TiCl4)
Why not the others: 'Benzoyl peroxide at 2000 atmospheres' is used to produce Low-Density Polythene (LDP); 'Concentrated sulfuric acid and KMnO4' are aggressive oxidizing agents; 'Anhydrous aluminum chloride...' is a Friedel-Crafts catalyst.
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