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

Show the properties of lithium aluminium hydride, Q. Show the properties of...

Q. Show the properties of Lithium Aluminium Hydride? Lithium aluminium hydride is much more useful than aluminium hydride. It is prepared in the laboratory by the action of LiH

Electrolysis laws by michael faraday., electrolysis laws by michael faraday...

electrolysis laws by michael faraday and how they helped him to find particle nature of electricity??

Show that water pressure increases with depth, Another way to show that wat...

Another way to show that water pressure increases with depth Search a tall tin can. Punch holes up the side of the can about 3 cm apart. Put a strip of adhesive or plastic tape

Write the cell reaction, Q. The equilibrium cell potential of the galvanic ...

Q. The equilibrium cell potential of the galvanic cell is found to be E cell , eq   = 1.410 V at 298.15K. The standard cell potential is E cell , eq = 1.360V. (a) Writ

Why formal charge does not give an accurate picture, Why Formal charge does...

Why Formal charge does not give an accurate picture Formal charge does not give an accurate picture, due to O is more electronegative than H; most of the positive charge is rea

Cengage online, There are three assignments due on the 25th I can''t give t...

There are three assignments due on the 25th I can''t give the questions because it is online

Entropy and second and third law of thermodynamics, ENTROPY Entropy is ...

ENTROPY Entropy is a thermodynamic property of a system. It is denoted as S and like as the enthalpy and internal energy, it is a state function. In thermodynamic expression, e

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