Which of the following alkenes is most reactive towards cationic polymerisation?
A.
$$C{H_2} = CHC{H_3}$$
B.
$$C{H_2} = CHCl$$
C.
$$C{H_2} = CH{C_6}{H_5}$$
D.
$$C{H_2} = CHCOOC{H_3}$$
Answer :
$$C{H_2} = CH{C_6}{H_5}$$
Solution :
In cationic polymerisation, carbocations are formed. Greater the stability of the carbocation, more reactive is the alkene. Since the stability of the intermediate carbocation follows the order :
$$C{H_3} - \mathop C\limits^ + H{C_6}{H_5} > C{H_3}\mathop C\limits^ + HC{H_3}$$ $$ > C{H_3}\mathop C\limits^ + HCl > C{H_3}\mathop C\limits^ + HCOOC{H_3}$$
therefore, reactivity decreases in the same order. Thus, styrene is most reactive.
Releted MCQ Question on Organic Chemistry >> Polymers
Releted Question 1
Among cellulose, poly ( vinyl chloride ), nylon and natural rubber, the polymer in which the intermolecular force of attraction is weakest is