Question 1
Addition polymerization
In addition polymerization, polymer is formed by addition monomer without eliminating any product at specified temperature, pressure and presence of catalyst. Different methods of addition polymerization are free radical polymerization, cationic polymerization, anionic polymerization and coordination polymerization. Mainly addition polymerization occurs in the monomers having double bound. This process has three stages initiation, propagation, termination.
Initiation: - free radicle attack monomer and form free radicle monomer this is called activated monomer.
Propagation: - activated monomers react each other and form growing polymer chain.
Termination: - the chain growth end at this stage.
Condensation …show more content…
Above Tg the rate depolymerization rate is very high compare to depolymerization it will lead to degradation of polymer when it use above Tg
Question 5
A) The ball which bounced has good resilience property other doesn’t have good resilient property. Resilience is the ratio of energy released in deformation recovery to the energy caused the deformation.
First ball has good elastic property when it hits the floor there is deformation occurs in the rubber ball. This deformation leads to change the location of molecules. After hitting the molecule try to attain its original position so it will try to reduce energy. Release of energy cause bouncing of ball.
The second ball is very rigid so there is no deformation occurs so there is no bouncing occurs.
B) When first ball immersed in liquid ammonia the temperature will reduce so there is no vibration of bond occurs in polymer. The ball became rigid so a little bouncing occurs in soft ball
Second ball became very rigid when it immerses in liquid ammonia. It may break when it hit …show more content…
the liquid doesn’t obey Newtonian law is called Non-Newtonian fluids. viscosity of non-Newtonian depends shear rate. Consider ketchup when stress increased the ketchup will flow faster than without stress
Eg:- ketchup, tooth paste, shampoo
Plasticizer
plasticizer is an additive used to improve properties of polymers. Plasticizer improves flexibility and durability of polymers. Plasticizer keeps the molecules apart by embedding between the polymer molecule. Plasticizer will reduce the cohesive force between the polymer chain. It increases the free volume and will decrease glass transition temperature. Plasticizers are mainly used in PVC.
Eg :- DINP, DIDP
Amorphous
Amorphous materials do not have crystalline structure. It has randomly ordered molecular structure. They don’t have sharp melting point.
Properties
• Low heat resistance
• Don’t have sharp melting point
• More transparent
• Lower shrinkage when cooled
• Very low dimensional stability
• High creep
Example :- nylon, acetal