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प्रश्न
Write preparation of low density polythene.
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उत्तर
Preparation of low density polythene:
- LDP is prepared by polymerization of ethylene under high pressure (1000 – 2000 atm) and temperature (350 – 570 K) in presence of traces of O2 or peroxide as initiator.
\[\ce{{n} CH2 = CH2 ->[Traces of O2 or][peroxide at 350–570 K, 1000–2000 atm] LDP}\] - The mechanism of this reaction involves free radical addition and H-atom abstraction. The latter results in branching.
- Polymeric chains are loosely held due to branching and the polymer has low density.
APPEARS IN
संबंधित प्रश्न
Write any ‘two’ uses of terylene.
Write the formulae of the raw materials used for preparation of Dextran.
Write the structure of melamine.
Choose the correct option from the given alternatives.
Which of the following is made up of polyamides?
Answer the following in one sentence.
Define the term: Vulcanization
Answer the following.
Write the reaction of the formation of Nylon 6.
Answer the following.
Name the polymer type in which following linkage is present.
\[\begin{array}{cc}\ce{- C - O -}\\||\phantom{.....}\\
\ce{O\phantom{.....}}\end{array}\]
Answer the following.
Draw the structures of polymers formed from the following monomers
H2N–(CH2)5 – COOH
Identify condensation polymers and addition polymers from the following.
-(CH2 - CH = CH - CH2 -)n
Monomer used for preparation of polyacrylonitrile is _____________
Write a chemical reaction for the preparation of the following polymer.
polyacrylonitrile
Write chemical reaction for preparation of the following.
Buna-S
Write the name of one example of each polymer in which following repeating units.
\[\begin{array}{cc}
\ce{(-CF2-CF2-), -[NH-(CH2)5-CO] -, -(CH2-CH-), (-CH2-CH2-)}\\
\phantom{............................}|\\
\phantom{..............................}\ce{CN}
\end{array}\]
Explain vulcanization of rubber.
Define rubber.
Explain the reactions involved in the preparation of viscose rayon.
Which of the following is used as a substitute for wool?
Identify additional polymers from the following.
I. \[\begin{array}{cc}
\ce{-(CH2 - CH -)_{{n}}}\\
\phantom{....}|\\
\phantom{.......}\ce{C6H5}
\end{array}\]
II. \[\ce{-(CH2 - CH = CH - CH2 -)_{{n}}}\]
III. \[\ce{-(CO(CH2)4 - CONH(CH2)6NH -)_{{n}}}\]
IV.
How many isoprene units are present in abscisic acid?
Identify the CORRECT statement regarding the following polymer.
\[\begin{array}{cc}
\phantom{....}\ce{O}\phantom{............}\ce{O}\phantom{...................}\ce{H}\phantom{.....}\\
\phantom{....}||\phantom{.............}||\phantom{...................}|\phantom{......}\\
\ce{-[C - (CH2)4 - C - NH - (CH2)6 - N -]_{{n}}}
\end{array}\]
Select the CORRECT match for both the polymers.
\[\ce{{n} CH2 = CH2 ->[333 K - 343 K][6 - 7 atm, catalyst] X}\]
Which of the following is CORRECT about polymer 'X'?
Identify the polymer obtained by polymerization of n moles of acrylonitrile.
Which of the following catalysts is used in preparation of terylene?
Which of the following compounds is used to prepare orlon?
Which among the following polymers is obtained from CH2 = CH – CN by polymerisation?
Which of the following polymer is used to make blankets?
Which among the following polymers is used to manufacture chemical containers?
Which among the following is an example of addition polymer?
Which of the following is not a semisynthetic polymer?
Which of the following polymers, need atleast one diene monomer for their preparation?
(i) Dacron
(ii) Buna-S
(iii) Neoprene
(iv) Novolac
Match the polymers given in Column I with the type of linkage present in them given in Column II.
| Column I | Column II |
| (i) Terylene | (a) Glycosidic linkage |
| (ii) Nylon | (b) Ester linkage |
| (iii) Cellulose | (c) Phosphodiester linkage |
| (iv) Protein | (d) Amide linkage |
| v) RNA |
Which of the following is not a copolymer?
Trans - form of poly isoprene is:-
Nylon threads are made of ______.
Identify the monomer used to prepare neoprene.
Which of the foolowing polymer is used in the manufacture of insulators.
The monomer of natural rubber is ______.
Answer the following.
Write the structure of isoprene and the polymer obtained from it.
Name and draw the structure of the repeating unit in natural rubber.
Write the name of the monomer of natural rubber.
Name and draw structure of the repeating unit in natural rubber.
Write the structure of isoprene and the polymer obtained from it.
Name and draw the structure of the repeating unit in natural rubber.
Name and draw structure of the repeating unit in natural rubber.
Write the structure of isoprene and the polymer obtained from it.
Write the structure of isoprene and the polymer obtained from it.
Name and draw structure of the repeating unit in natural rubber.
Write the structure of isoprene and the polymer obtained from it.
Name and draw structure of the repeating unit in natural rubber.
Write the structure of isoprene and the polymer obtained from it.
