# Is each bag of plastic a polymer/macromolecule? If yes, why does it tear so easily? [duplicate]

For example, polyethene is a macromolecule. So each bag of polyethene should be one molecule. Doesn't tearing it therefore involve breaking strong covalent bonds? Shouldn't the energy needed to do this be very high? But it tears pretty easily, wondering why this is so.

Any insights welcome!

• Oct 23 at 16:04

The tear beyond elasticity likely starts with breaking these intermolecular bonds keeping the individual molecules together; these are weaker than the covalent $$\ce{C-C}$$ and $$\ce{C=C}$$ bonds within a polymer chain.