Addition Polymerisation

What is hydration?

Addition of water to a molecule

What are the conditions for industrial hydration of ethene?

300-600°C

70 atm

Concentrated H₃PO₄ catalyst

Why is industrial hydration preferred over the sulfuric acid method to produce alcohol?

Higher atom economy and no waste products.

What type of monomer forms addition polymers?

Alkenes

What is addition polymerisation?

Many alkene monomers join together to form a polymer.

Why are poly(alkenes) relatively unreactive?

They contain strong C-C and C-H bonds

What must be shown when drawing a repeating unit?

Bonds extending through the brackets.

What should NOT be included if asked to draw ONE repeating unit?

The "n"

What properties does poly(chloroethene) (PVC) have?

Waterproof, electrical insulator, resistant to acids

Why is pure PVC rigid?

Strong intermolecular forces prevent polymer chains moving.

What does a plasticiser do to PVC?

Weakens intermolecular forces so chains move more easily.

Give one use of rigid PVC.

uPVC window frames or guttering

Give one use of plasticised PVC

Electrical wire insulation or waterproof clothing

Why are addition polymers unreactive?

contain strong C-C and C-H single covalent bonds which are difficult to break

what is a polyalkene?

addition polymers made from alkenes

Why do polyalkenes not react easily with most chemicals?

They do not contain reactive functional groups, only strong carbon-carbon and carbon-hydrogen bonds

What intermolecular forces exist between polyalkene molecules

Van der Waals' forces

Explain the intermolecular forces between molecules of polyalkenes

Polyalkenes have van der Waals' forces between polymer chains caused by temporary dipoles

Why are intermolecular forces stronger in long-chain polymers?

Longer polymer chains have more electrons and greater surface area, leading to stronger van der Waals' forces