C.1 Petrochemicals

• Polymers – large molecules coomposed of 500 to 20000 or more repeating units of simpler molecules known as monomers.

• Petrochemicals – compounds from oil or natural gas.

• Ex. Detergents, pesticides, pharmaceuticals, cosmetics…

• Synthetic polymers – paint components, fabrics, rubber, foams,…

• Double covalent bond – ethene, ehylene, carbon is bonded to carbon with 2 bonds.

• Chemists use hydrocarbons and knowledge of carbon and covalent bonding to build new molecules

• Until 1800s all materials were natural materials. Eg stone, wood, cotton, silk

• Commercially made products: cellulose from wood and shellac from insects. These are polymers – long chain molecules made out of monomers

• Modern products are more man-made. Petrochemical – man-made out of petroleum. Eg: insulation, plastic, foam, fabrics like nylon, detergent, pesticides

Ethene – builder molecule

• C2H4

• Aka ethylene• Contains a double covalent bond• The double bond is very reactive• Ethene and water form ethyl alcohol• Addition reactions – adding a reactant onto double

bond

Addition Reactions, cont’d

• Ethene can do an addition reaction with itself. • Makes polyethylene – contains 500 to 20,000

ethenes linked in a chain• Polyethylene is an example of an “addition

polymer”• Other polymers are made from monomers like

ethene: eg vinyl chloride to Polyvinylchloride (PVC)

Polymers

• Polymers can be long straight chains (like spagetti), branched, or cross-linked

• http://www.youtube.com/watch?v=C1aAKG5qmT0

Polymer Structure

• Branched polymers – branches perpendicular to the main chain.

• Linear polymer – do not connect• Cross linking – makes polymers more rigid,

cross linked, can’t slide.• Ex. Soda bottle, soda bottle cap, which one

has more cross linking?

Beyond Alkanes

• Saturated hydrocarbons – each carbon atom forms as many single covalent bonds.

• Alkenes – double bonded• Alkynes – triple bonded• Alkanes – single bonded• Unsaturated hydrocarbons – carbon double

bonded or tripled, does not have the max amt of hydrogen bonds.

Substituted alkenes: Functional Groups

• Ester –scented C• O - C = O • R = carbon chain• Alcohol• C – OH• Cycloalkanes – rings• Aromatic compounds – benzene, double bonded

• Carboxylic acids – C =O and - OH

Sec. D Energy Alternatives to Petroleum

• Biomolecules – organic molecules found in plants and animals.

• Oil shale – petroleum from tar sands and oil shale rock.

• Coal liquefaction – liquid fuel produced from coal. The present cost of mining and converting coal to liquid fuel is greater than that of producing the same quantity of fuel from petroleum.