1) What do you mean by plastics? Write down the essential differences between thermoplastic, thermosetting and elastomer resins. Explain with suitable examples. Explain about various kinds of resins. Explain the manufacture of phenol-formaldehyde resin with a neat and suitable flow diagram. Explain the viscose process for manufacture of Rayon fiber indicating with the steps involved in detail. Compare natural and synthetic rubbers. Describe how natural rubber is prepared? Write down its significant properties.