Hydrocarbons: & Polymers:

A Hydrocarbon is a compound that is mostly made of hydrogen and carbon atoms. Hydrocarbons may be linear or branched, cyclic (ring shaped) or polymers. (see below) - All hydrocarbons are organic compounds. Organic Compound = a compound that contains carbon atoms. – (Exceptions are CO2, CO, diamond, graphite, etc.)

Combustion Of Hydrocarbons - Combustion is a type of chemical reaction. -Hydrocarbon reacts with oxygen gas (burns) and forms carbon dioxide and water vapor Ex. C 2 H 6 + O 2  CO 2 + H 2 O *Balance the equation!

A “polymer” is something made of many units. “mer” = each link in the chain or single unit. (monomer) mono = “one” (polymer) poly = “many”

- Many monomers bond together to form a long chain, called a “ polymer ”. -A single Covalent bond shares 2 electrons, and hold polymers together. - when hydrogen atoms bond to carbon atoms, the compound is called a “hydrocarbon”.

Types of Monomers :

POLYMERS can be Natural or Synthetic Natural is made by nature. commonly made by plants. Commonly made of the elements; –C, H, O, + N, F, P, S, Cl, Br, & I Uses = cotton, rubber, starch, cellulose, fiber, glycogen. Synthetic means “man made” or not found in nature. UsesUses = plastics, rubber, carpet fibers, styrofoam speaking of plastics….

High Density & Low Density Plastics High density plastics are stronger, with a greater tensile strength and more abrasion resistant than low density plastics. High density plastics examples = black construction bags Low density plastics examples = grocery bags.

LDPE –More flexible and soft –Not as strong –More branches HDPE -long chains -more rigid -can be regularly packed

Recycling plastics… What does that little number in the triangle mean? Resin code- identifies the type of plastic used

Thermoplastics Don’t undergo a chemical change in composition when heated Can be re-melted and reshaped again and again Are recyclable

Thermosetting plastics Can melt and take shape only once Heat (or chemicals) causes a cross-linking process and forms a rigid plastic Can’t be recycled but can be reused

a.Weak bonds; molecules slide past each other when heated b.Stronger (cross-linked) bonds; rigid structure even when heated

Vulcanization Is an example of thermosetting Sulfur is added to rubber and is then heated Cross-links form Vulcanized rubber is durable and elastic (think car tires)

Biopolymers Produced by living things Common example is cellulose (in cotton, wood, etc.) Can be used for plastics -biomass from crops can be used to produce polyethylene

Play the game! Cut out the slides that follow and place them into the following categories: Natural polymer Artificial (manmade) polymer

Wool (from the protein keratin, a polymer)

Glucose and Cellulose –The polymer cellulose is made up of the monomer glucose. Each year, plants synthesize over 1 trillion tons of cellulose, making it one of the most common naturally occurring polymers

Glucose/carbohydrates

Lipids (fats/vegetable oils) Fatty acids make up saturated/unsaturated fats

Amino acids/proteins

Hydrocarbon gases used for fuel

Nylon

Kevlar

Vulcanized rubber

Polyethylene (from petroleum)

Polystyrene