Polymer bonds are typically formed by

• A. Covalent bonds only
• B. Covalent and secondary
• C. Ionic bonds
• D. Metallic bonds

Answer: (B)

Polymers combine strong covalent bonds along the main chain with weaker, noncovalent interactions between chains. The covalent bonds form during polymerization and hold the monomers into long sequences, while the weaker secondary bonds between neighboring chains—such as van der Waals forces, dipole-dipole interactions, and hydrogen bonding in certain polymers—help hold the material together and influence properties like rigidity, melting/softening behavior, and toughness. That mix is why the typical description is covalent and secondary.

Ionic bonds aren’t the usual interchain force in most polymers (except in special polyelectrolytes or ionic polymers), and metallic bonds aren’t characteristic of organic polymers either. Saying covalent bonds only ignores the important interchain interactions that govern real polymer behavior.