How can you improve the properties
of natural rubber for industrial
application?
Answers
Answer:
a process called valcanisation helps in this
Answer:
Crude rubber becomes hard and brittle in winter and soft and sticky in summer. Treatments to improve and modify natural rubber properties is therefore subjected to following treatments to improve and modify natural rubber properties.
(i) Compounding.
Explanation:
To crude rubber are added certain compounds to modify natural rubber properties. The compounds that are added are vulcanizing agents, plasticize rs, accelerators, fillers, hardeners, reinforcing agents and pigments.
Vulcanizing agents are substances like sulfur which when added to crude rubber reduce its plasticity while maintaining its elasticity. These are essential for vulcanization of rubber.
Plasticize rs are materials like vegetables oils, rosin and wax etc. that soften the crude rubber.
Accelerators are substances like white lead, lime, magnesia etc. which when added hasten the process of vulcanization and reduce the requirements of sulphur.
Fillers are substances like lamp black, oxide of iron or zinc, china clay, magnesia, and silica etc. that modify the properties of rubber and at the same time reduce its cost. Substances that increase tensile strength of rubber are called reinforcing agents. Lamp black and zinc oxide are both fillers and reinforcing agents.
Hardners are substances like barium sulphate, calcium carbonate and sealing wax that give hardness to rubber and increase its tensile strength. Hard rubber withstands high temperature better.
Pigments are substances like ferric oxide, lithophone and lead chromate etc. that are added to give desired colour to rubber. Compounded rubber is hard, tough, weather and water resistant.