Polymers Question 8
Question: 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
Show Answer
Answer:
Correct Answer: A
Solution:
$ 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 then reacts stepwise with a large number of ethylene molecules ultimately leading 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- 0.92 $ g/cm^{3} $ and m.pt. 384K)
BETA
