[kanaka@mme]

why pvc (polyvinyl chloride) pipes do not corrode..?

[fledarmus]

1) What is the chemical structure of polyvinyl chloride?

2) What do you know about the chemical reactivity of that type of structure?

[kanaka@mme]

PVC has a very regular structure with a chlorine attached to every second carbon atom in the chain.PVC is a polymer made from vinyl chloride monomers.


It shows high resistance to chemical degradation.It is resistant to oxidation and thus has a long lifespan.And this reason makes it to uncorrode.

[fledarmus]

Saying that it has high resistance to chemical degradation and that it is resistant to oxidation is almost the same thing as saying that it doesn't corrode - corrosion IS chemical or oxidative degradation. That isn't a reason WHY it doesn't corrode.

The clue is in the structure. The "very regular structure" that you mention is a long chain alkane with secondary chloride groups. There are not many reactions that alkanes will undergo, and the few there are generally involve free radicals. Halogens tend to inhibit free radical reactions, so added halogens along the alkane chain reduce the reactivity of the alkane even further. As for the secondary halogens, these can undergo elimination and substitution reactions, but chlorine isn't that great of a leaving group and the reactions occur with difficulty, using strong bases or very strong nucleophiles and highly solvating conditions.

[kanaka@mme]

thank you sir..