Common Misconceptions

⚠️ Common Misconceptions

Misconception 1: "Polymers are held together by intermolecular forces alone"

Within each polymer chain, the atoms are held together by strong covalent bonds — not intermolecular forces. The intermolecular forces act BETWEEN the separate chains. The covalent bonds within the chains are what give polymers their length and stability. Intermolecular forces between chains determine the physical properties (melting point, flexibility). Both types of force are present.

Misconception 2: "All plastics/polymers are the same"

There is enormous variation in polymer properties depending on the monomer used, the chain length, and the arrangement of chains. Low-density poly(ethene) is soft and flexible (chains randomly tangled, shorter); high-density poly(ethene) is stiffer (longer chains aligned more regularly, more intermolecular contact). Kevlar (used in bulletproof vests) and nylon have completely different properties from poly(ethene) because they are made from different monomers.

Misconception 3: "The double bond is completely broken in addition polymerisation"

Only ONE of the two bonds in the C=C double bond breaks during addition polymerisation. The other bond becomes the C-C single bond that forms the backbone of the polymer chain. Each monomer goes from having a double bond (C=C) to providing two single bonds (—C—C—) in the chain. No atoms are lost — all atoms from the monomer appear in the polymer repeat unit.