Production of rubber ducks

Rubber got its name when an english scientist called Joseph Priestly figured out that rubber can "rub out" pencil marks. There are two types of rubber, natural rubber(NR) and Styrene-butadiene rubber (SBR. I will now explain how each is made. Natural rubber:The biggest producers of natural rubber are Thailand, Indonesia and Malaysia. They make up 80% of the worlds rubber.Hevea brasiliensis is the tree of which sap is taken from and then used to make rubber. Each tree can make up to 30-35 grams of rubber per day given the amount of sap produced. Acetic acid is added to coagulate the sap. (Coagulation is when parts of liquid are made semi solid. The rubber is made into sheets and passed through a mill and then washed and dried. Natural rubber is said to have the most elasticity of all rubbers and is not damaging to the ozone layer. Natural rubber is mainly used for heavy duty purposes eg tyres. It also is made into rubber bands. SBR: This is the cheapest and most common ruibber in the world. This rubber is made from oil which is a fossil fuel. It is more harmful to the earths enviornment. Interesting facts om rubber: Christopher Columbus discovered natural rubber when the natives of Haiti were playing with a ball of sap taken from the trees.(1496 to 1492) Thomas Hancock invented a machine called "masticater" that allowed the rubber to be softened, mixed and shaped.(1820)