Polyacrylonitrile is commonly used as fiber reinforcements in composites, including in concrete and in polymer matrices $($more on composites really soon$).$ It is susceptible to hydrolysis, but it doesn't really break down into a liquid like a hydrolysis$-$susceptible polyester.At which bond does PAN degrade?

The following multiple$-$choice options contain math elements, so you may need to read them in your screen reader's $$reading$$ or $$browse$$ mode instead of $$forms$$ or $$focus$$ mode.

Choice $1$ of $9$:H$$H

Choice $2$ of $9$:C$$H

Choice $3$ of $9$:N$$H

Choice $4$ of $9$:C$$C

Choice $5$ of $9$:C$=$C

Choice $6$ of $9$:C$$C

Choice $7$ of $9$:C$$N

Choice $8$ of $9$C$=$N

Choice $9$ of $9$:C$$N