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There are two major categories of rubber; natural and synthetic. The most popular compounds are;

Natural Rubber
Vulcanised Rubber
Synthetic

History

Thousands of years BC Indians living in Central and South America were using latex to makewaterproof clothes and shoes using latex from rubber trees.

It was unknown in Europe until 1731when French explorer Charles Marie de La Condamine sent back samples of rubber to Europe. It was put to a variety of uses In 1770 Joseph Priestley found he could use pieces of rubber to erase pencil marks.

Others used it to waterproof cloth a series of discoveries that eventually led to Charles Macintosh inventing and patenting the rubberized, waterproof coat or macintosh. But it wasnt until 1839 when American inventor Charles Goodyear discovered how to vulcanize rubber that it really came into its own.

Natural Rubber

also called Latex or Para

Natural rubber is made from latex
Latex is the white liquid that oozes from certain plants when you cut into them.There are around 200 plants in the world that produce latex including dandilions.
99 percent of natural rubber comes from a tree called Hevea brasiliensis, or the rubber tree.

  • Though it’s sometimes mistaken as the sap of the Hevea tree, latex actuality runs through ducts in a layer just outside the cambium below the tree’s bark.
  • The rubber tree originates from South America.
  • 90% of all natural rubber comes from these trees grown in rubber plantations mainly found in Indonesia, the Malay Peninsula and Sri Lanka.
  • This type of rubber is often called Para rubber.

However by itself, unprocessed natural rubber is not all that useful. It tends to be brittle when cold and smelly and sticky when it warms up.

So it is combined with a range of addatives to give it added strength and flexibility.

The tough rubber used for tyres and such like has been further processed or vulcanised.

Vulcanised Rubber

Latex is filtered, washed, and reacted with acid to make the particles of rubber stick together.
Mastication machines “chew up” raw rubber using mechanical rollers and presses to make it softer, easier to work, and more sticky.
Addatives chemical ingredients are mixed in to improve its properties (for example, to make it more hardwearing).
Next, the rubber is squashed into shape by rollers (a process called calendering) or squeezed through specially shaped holes to make hollow tubes (a process known as extrusion).

Finally, the rubber is vulcanized (cooked): sulfur is added and the rubber is heated to about 140°C (280°F).

Biodegradable?

Latex when made from rubber trees a natural sounds like it should be biodegradable. Which has led to claims that that non-vulcanised products like latex condoms and other products  are.

This is hotly debated!
Most latex products contain addatives to make them (amongst other things) stronger. It all depends on wether they are biodegradable or not.

While many people say that simple rubber products people  do eventually decompose, (not proven),  it takes such a long time as to make any claims of biodegradability  misleading.Certainly the anti-balloon camp do not consider latex balloons to be biodegradable despite what the balloon industry say.

And yet this….

  • Very thin rubber products, such as balloons and condoms, will degrade naturally especially if they are subjected to natural sunlight. As is evident from the problems which are associated with sealing rings natural rubber is capable of being biodegraded. It should be possible to compost thin rubber articles
  • In a composting environment, biodegradation rates over 24 weeks were twice that compared to the fertilized treatment in soils. Degradation of natural rubber condoms in soil was slower compared to gloves with 42% of the initial weights remaining after 48 weeks. In contrast, the manufactured polyurethane condoms were hardly biodegradable.

Read more here

It is possible to buy natural latex foam rubber. For example
100% Natural Latex, Pure Comfort, Talalay rubber not foam, offering maximum comfort and luxury, available in Soft, Medium or Firm.read more here. I

and latex sheets like these

Both of the above have been described as biodegradable.

However vulcanised rubber generally is not. Though there are some suggestions that it may eventually biodegrade more research needs to be done.

Synthetic rubber on the other hand is not biodegradable.

Synthetic Rubber

Is produced primarily from petrochemicals by a chemical process known as polymerisation. You can read about polymers and polymerisation here.

Synthetic rubbers

Including
* SBR
* Neoprene
* Hypalon
* Nitrile
* Butyl
* EPDM
* Silicone
* Viton

Polychloroprene
Polyurethane

SBR – Styrene-butadiene or styrene-butadiene rubber (SBR) describe families of synthetic rubbers derived from styrene and butadiene (the version developed by Goodyear is called Neolite). These materials have good abrasion resistance and good aging stability when protected by additives.

Neoprene the brand name for polychloroprene often used for dive suits

Butyl rubber,
is gas-impermeable,
is commonly used for inner tubes.
Most modern chewing gum uses food-grade butyl rubber as the central gum base.
The raw materials for making butyl rubber are isobutylene and isoprene. These two components are polymerized at -100 °C

Poly(styrene-butadiene-styrene), or SBS, is a hard rubber that’s used for things like the soles of shoes, tire treads, and other places where durability is important. It’s a type of copolymer called a block copolymer. Its backbone chain is made up of three segments. The first is a long chain of polystyrene, the middle is a long chain of polybutadiene, and the last segment is another long section of polystyrene.

Silicone – read up here

High Quality Rubber Coated Textiles
Also known as technical coated textiles or rubber proofed fabrics, rubber coated textiles grant rubber characteristics to a wide variety of fabrics and materials.
We are able to coat fabrics with a wide variety of rubber compounds, some of the most popular compounds are;
* Natural Rubber
* SBR
* Neoprene
* Hypalon
* Nitrile
* Butyl
* EPDM
* Silicone
* Viton
* Polyurethane

More

Read more about the different types of plastic here

Why This Post Is ….

A little bit rubbish. You are reading a work in progress. Here’s how the blog is written and why we post half cocked.

 

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