Question

PVC have more intermolecular force of attraction than natural rubber?

Answer 1

PVC consists of polar molecules which are attracted to each other by dipole-dipole interactions due to electrostatic attractions of a chlorine atom in one molecule to a hydrogen atom in another atom: These considerable intermolecular attractions between polymer chains make PVC a fairly strong material.
But in chains of natural rubber involves weak van der Waal force of interaction.