Question #$3$

$25$ Marks

Water$-$soluble polymer PVA $($Polyvinyl Alcohol$)$ is degraded in a photochemical

reactor where the polymer degradation steps are shown in the Figure below.

Hydrogen peroxide is utilized as the oxidant and the UV light as the energy

source.

Referring to the reaction mechanism discussed during the lecture, describe

the PVA degradation process.

It was shown that the MWD distribution broadens during the PVA

degradation. Explain why the MWD gets wider $?$

Comment on the performance of each reactor type $($batch$,$ fed$-$batch and

continuous$)$ to degrade the PVA polymer.