Write the structure of Monomers used for getting the following polymers:

(a) Novolac


(b) Neoprene


(c) Buna - S


OR


(a) Write one example each of


(i) Cross-linked polymer.


(ii) Natural Polymer


(b) Arrange the following in the increasing order of their intermolecular forces:


Terylene, Buna - N, Polystyrene


(c) Define biodegradable polymers with an example.


(a) The monomers of novolac are o-and/or p-hydroxymethylphenol derivatives.



(b) The monomer of neoprene is 2- Chloro- 1, 3- butadiene.



(c) The monomers of Buna- S are styrene and 1,3- Butadiene.



OR


(a) (i) Bakelite


(ii) Proteins


(b) Buna-N s a type of rubber, Polystyrene is a type of thermoplastic polymer and Terylene is a type of fibre.


The intermolecular forces are strongest in fibres then in plastics and weakest in rubbers. Thus, polymers in increasing order of intermolecular forces are arranged as follows-


Buna-N < Polystyrene < Terylene


(c) Biodegradable polymers are those polymers which can be decomposed by microorganisms with time and do not cause pollution. E.g. PHBV, Nylon 2–nylon 6, etc


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