35.3.1—Poly(alkenes) are chemically inert

In a poly(alkene), the original C=C bonds have become strong C–C single bonds in a saturated carbon backbone. With no easily attacked functional group, the material is relatively chemically inert.

This stability gives useful durability but also makes many poly(alkenes) difficult for organisms and ordinary conditions to biodegrade.

Poly(ethene) packaging can remain for long periods because hydrolysis has no ester or amide link to attack; fragmentation by sunlight is not the same as complete biodegradation.

“Inert” does not mean indestructible or non-reactive under every extreme condition; it means resistant under ordinary biological/environmental conditions.