Which among the following statements is NOT true about high density polythene?
Which among the following statements is NOT true about high density polythene?
It is obtained from ethene.
It needs high pressure $(1000-2000 \mathrm{~atm})$ for synthesis.
Polymerization occurs in presence of Zieglar-Natta catalyst.
Melting point is higher than LDP.
Solution
HDP is obtained by polymerization of ethene in presence of Zieglar-Natta catalyst at a temperature of $333 \mathrm{~K}$ to $343 \mathrm{~K}$ and a pressure of 6-7 atm. Its melting point (in the range of 144$150^{\circ} \mathrm{C}$ ) is higher than that of LDP (melting point $110^{\circ} \mathrm{C}$ ).