Mumbai University > First Year Engineering > Sem1 > Applied Chemistry 1

Marks: 5M

Year: May 2012, May 2013

Natural rubber is obtained from latex, a milky emulsion, collected from rubber tree. The bark of rubber is cut at intermittent places. The latex starts dripping which is collected in a container. It is nothing but a milky white emulsion of isoprene. The % of isoprene is about 30-40% and remaining is water. On earth there are about 500 different species of rubber trees. Drawbacks and properties-

• It becomes softer at higher temperature and brittle at lower temperature.

• Very weak with tensile strength of 200 kg/cm2.

• It has large water absorbing capacity

• It has very little durability

• It perishes due to oxidation in air

• It swells considerably in organic solvents

• It has high tackiness due to which it is difficult to store

• If stretched to greater extent leads to permanent deformation.