Plastid
tulemusena saadakse kõrge molekulmassiga (70 000 ... 2 500 000)
looduslik kautsuk.
Vulkaniseerimise käigus väävli manulusel tekkivad polümeeri
molekulide vahele 2-10 väävli aatomi pikkused ristsidemed, muutes
oluliselt materjali elastseid omadusi.
Vulkaniseerimisel suure hulga väävliga saadakse mitteelastne nn.
kõvakummi e. eboniit.
Lisandina sisaldab kummi täiteaineid (tahma või valgetahma
(ränidioksiid), plastifikaatoreid, stabilisaatoreid, pigmente jms.).
Current sources
Close to 21 million tons of rubber were produced in 2005 of which around
42% was natural. Since bulk of the rubber produced is the synthetic variety
which is derived from petroleum, the price of even natural rubber is
determined to a very large extent by the prevailing global price of crude oil.
Today Asia is the main source of natural rubber, accounting for around 94%
of output in 2005
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