4.1.3 alkenes

a homologous series of unsaturated hydrocarbons containing a C=C bond

alkenes

sideways overlap of adjacent p-orbitals above and below the bonding C atoms

pi bond

overlap of s-orbitals directly between the bonding atom

sigma bond

the π-bond locks the 2 carbon atoms in position and prevents them from ___ around the double bond

rotating

-alkene are non-polar, water is polar
-alkene will only dissolve in non-polar solvents, as like dissolves like

insoluble in water

-longer chains have more surface area contacts
-so they have more London forces

boiling point increases with chain length

compounds with the same structural formula but with a different arrangement in space

stereoisomers

E isomer

atoms on opposite sides

Z isomer

atoms on sakesides

alkene + hydrogen

alkane, nickel catalyst

alkene + halogen

dihaloalkane

alkene + hydrogen halide

haloalkanes

alkene + H20

alcohol, acid catalyst

electrophile

an electron pair acceptor

-discarded polymers are sorted by type
-they are chopped into flakes, washed, dried and melted
-the recycled polymer is cut into pellets and used to produce new products

recycling

-high Cl contents makes recycling dangerous
-solvents can be used to dissolve it

PVC recycling

-if derived from petroleum or natural gas they have a high stored energy value
-they can be incinerated to produce heart which generates steam to drive a turbine producing electricity

fuel

-the chemical and thermal processes that reclaim monomers, gases or oil from waste monomers
-products are similar to those produced from crude oil in refineries
-can be used as raw materials from the production of new polymers
-doesn't need sorting or washing

Feedstock recycling

-produced from plant starch, cellulose, plan oils and proteins
-broken down by microorganism into H2O , CO2 and bio compounds
-they leave no visible or toxic residues

biodegradable polymers

-oil-based polymers
-contain bonds that are weakened by absorbing light to start the degradation

photodegradable polymers