Natural rubber, Chemistry

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.

 

 

Posted Date: 7/21/2012 8:21:01 AM | Location : United States







Related Discussions:- Natural rubber, Assignment Help, Ask Question on Natural rubber, Get Answer, Expert's Help, Natural rubber Discussions

Write discussion on Natural rubber
Your posts are moderated
Related Questions
The first ionization potentials for Na, K, and Rb are 5.138, 4.341, and 4.166 eV, respectively. Assume that the energy level of the outer electron can be represented by a hydrogenl

Nitric oxide becomes brown when released into the air

Explain why nichrome and not copper is used as heating element whereas manganin is used as standard resistance? For heating elements, primary requirements are high melting poin

Q. Define homogeneous mixture ? A homogeneous mixture is one which has a constant composition throughout. By mixed sugar in water you create a homogeneous mixture. A homogeneo

Conformation energy profile for cyclohexane ring flip   cyclohexane ring flip

factors affecting TGA

Give the styx code of b4h10 and which type of bond present in it?


Coordination number and geometry   Binary compounds are ones with two different elements present. 'Simple' crystal structures can be classed as ones in which each atom (or