ESL Lesson 7

Rubber

Lesson Objective: To have students discuss products that are made of rubber and talk about how man-made and natural rubbers are different.

Open Discussion Topic:
Have your students brainstorm to think of what is made from rubber. Tires are always first on the list followed by, soles of shoes, rafts, gloves, and garden hoses which are all common, but there are also airplane emergency slides, engine hoses that can handle hot liquids and earphone coverings. Within every car there are door, window and trunk seals that keep the rain and dirt out. Mines, grain factories and recycling plants all need rubber based conveyor belts to move materials around. There quite a few rubber based products that we use every day but don't think about. Don't forget that mouse pad next to your computer, it’s rubber based too.

Extension Activity:
Rubber comes to us from two sources: nature and man. Listed below are some common rubbers around the world and what they are used for.
SBR: Styrene/Butadiene is excellent for underground mining when mixed with flame retardants so they do not catch fire.
NBR: Acrylonitrile/Butadiene can resist oil, solvents, chemicals and fuel.
EPDM: Ethylene Propylene Diene has excellent resistance to ozone and sun rays.
Natural Rubber Latex: This is natural rubber sap from trees grown in rubber plantations.

The above rubbers SBR/NBR/EPDM are 100% synthetic (not natural) made from oil, so when the price of oil goes up, rubber companies look for natural rubber latex from trees to use as filler because it is cheaper, but not as strong as synthetic. Discuss how high energy prices will affect the price of natural latex.

When the oil price goes up there is more demand for natural rubber, when oil price goes down there is more demand for synthetic rubber. It is an inverse (opposite reverse) relationship. Discuss how high oil prices will make rubber, whether natural or synthetic more expensive.

Unit 7 Focus:
As prices for oil continue upward, what countries will increase their rubber exports? Have students make a list of countries in Asia and Africa that grow rubber trees and collect natural rubber latex for export. Thailand, Indonesia, Vietnam and Malaysia account for 80% of worldwide exports, what countries does the other 20% come from? Answer: Liberia, Nigeria and Cambodia. Keep in mind 70% of worldwide exports go to United States, China, Japan, Korea Republic, Germany, and France.
If oil prices get too high, (say $100-$130a barrel) every company on the planet will want natural rubber. Will there be enough at that time or will demand out strip supply? Will new plantations be started to make a fast buck ? (Slang for to make money fast). Where will this land come from to plant all of these new trees? Will more rainforest be cut to plant rubber trees?

Discussion Activity 2:
Now have students review Delivery Systems lesson and give ideas about how delivery systems will affect the rubber export trade, especially the trade-off of buying natural rubber which is cheaper than synthetic rubber vs. the high shipping costs around the world. In Asia most rubber deliveries are done by Break-Bark, where a ship is loaded with rubber slabs without containers in a central hold area. This delivery method is cheaper than containerization. Be sure to ask if they think rubber is important, or can we live without it?

**(Note: David DuByne) Watch for natural rubber latex prices to go high from Sept 2007- Dec 2007 and Jan 2009- Dec 2009. Also watch for an increase in (Copra) Coco-diesel and Palm Oil (oil from Oil Palm tree) prices, used as bio-diesel fuels. There could be competition between crops for available/usable land space to be grown. As the price goes up everyone will want to grow for profit and start new plantations of all three trees at the same time. [Lag time] **

Continue to: Bio-fuels and Ethanol

TOP

ESL Lesson 7

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Rubber
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Bio-fuels and Ethanol
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Liquid Fossil Fuels
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Grain Ethanol
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Sugarcane Ethanol
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Cellulosic Ethanol
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Biodiesel
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Biomass Gasification
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Wind and Solar
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Conservation
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