Natural rubber, Chemistry

Assignment Help:

Natural rubber: Natural rubber is obtained by making small incisions on the bark of certain types of trees, like "Have a brasiliensis" and "Ganynle". White milky liquid substance (rubber latex) from the rubber tree by tapping is obtained. Latex is sieved to remove impurities then coagulated using coagulants like acetic acid or formic acid. Coagulated mass convert into coagulum. Coagulum is washed, dried and treated as follows:

1. Copper rubber: It is prepared by adding, little amount of sodium bisulphite, a retarder prevents, the discoloration and softening of rubber. Coagulum is allowed to drain for about two hours and after that it is passed through a creeping machine to form sheets of rubber of about 1 mm.

2. Smoked sheet: For preparing smoked sheets coagulation is carried out in long tanks. Sides of the tank have vertical grooves fitted with metal plates. First, dilute latex is added into the tanks and before that plates are removed. Coagulating agent, formic acid or acetic acid is then added and mixture is thoroughly stirred then plates are fitted and allowed to dry slabs are formed.

 

 


Related Discussions:- Natural rubber

Uses of aluminium, Q. Uses of Aluminium? Aluminium exhibits useful prop...

Q. Uses of Aluminium? Aluminium exhibits useful properties of low density, high thermal and electrical conductivity, and good corrosion resistance with non-toxic nature of the

Hydrogen, It is stated that Bohrs theory is applicable to hydrogen like ion...

It is stated that Bohrs theory is applicable to hydrogen like ions.why? Ans) It is not stated in bohr''s theory but it is a drawback of his theory. The reason for this is

Assignments, I have 4 assignments for unit 22 chemistry btec level. Are you...

I have 4 assignments for unit 22 chemistry btec level. Are you able to do my assignments by friday?

The hydration of propene, The hydration of propene The hydration of pro...

The hydration of propene The hydration of propene includes the usual mechanistic steps of alkene protonation to form a carbocation followed by the nucleophilic reaction of wate

Osmotic pressure, Osmotic pressure: Osmosis process is the movement of ...

Osmotic pressure: Osmosis process is the movement of a solvent from a solution of lower solute concentration (higher solvent concentration) to one of the higher solute concentr

Periodic table, what groups comprise each block of elements in the periodic...

what groups comprise each block of elements in the periodic table?

Physical chemistry, What happens when a melt containing 1% Ag and 99% Pb is...

What happens when a melt containing 1% Ag and 99% Pb is cooled?

Explain cis- and trans-3-hexene, Explain cis- and trans-3-hexene Both ...

Explain cis- and trans-3-hexene Both cis- and trans-3-hexene should give the similar one alkyl halide product when they react with HI, and both would undergo catalytic hydroge

Show applications of coordination compounds, Q. Show Applications of coordi...

Q. Show Applications of coordination compounds? Innumerable applications of coordination compounds in fields as divergent as biology,  industry. Agriculture, analytical chemist

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd