High density polyethylene `(` HDPE `)` can be prepared from ethylene by

Options

A. Ziegler`- ` Natta process
B. Heating with peroxides
C. Condensing in sealed tubes
D. Condensing with styrenes

Answer

A

Explanation

`HDPE` is prepared by co`-` ordination polymerization which occurs through the intermediate formation of co`-` ordination complexes. For example, ethylene first forms a co`-` ordination complex with the transition metal titanium by donating its `pi-`electrons. The `pi-` complex thus formed than reacts stepwise with a large number of ethylene molecules ultimately leadiing to the formation of a polymer. The polythene so obtained has high density `(0.97g//cm^(3))` and higher `m. pt. (403K)` as compare to `LDPE(` density `-0.92g//cm^(3)` and `m. pt 384 K)`.