In this paragraph, it is written that coal tar is used as starting materials for manufacturing of various.......
What is the meaning of starting materials, here?
Coal tar is among the byproducts when coal is carbonized to make coke or gasified to make coal gas.It is obtained as a by product during destructive distillation of coal to make coke in coke oven process.
It contains benzene, naphthalene, phenol, aniline etc.
1. It is used in building projects and home repairing, for roofing as a sealant .
2. It is also used in sealing the pitches in the roof, roads, and providing water tight seal for all angles of the roof line.
3. It is also used as insulating agent which insulates wall to maintain a comfortable temperature inside the building.
4. They are also used in a no. of exterior paints.
Starting material means raw material. Many products can be obtained from coal tar by processing it further.