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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.
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संबंधित प्रश्न
Write any ‘two’ uses of terylene.
Write the reactions involved in the preparation of PVC
Write the formulae of the raw materials used for preparation of Dextran.
Write the monomers of the following polymer :
Choose the correct option from the given alternatives.
Which of the following is made up of polyamides?
Answer the following in one sentence.
What type of intermolecular force leads to high-density polymer?
Answer the following.
Write structure of natural rubber and neoprene rubber along with the name and structure of their monomers.
Answer the following.
Match the following pairs:
| Name of polymer | Monomer |
| 1. Teflon | a. CH2 = CH2 |
| 2. PVC | b. CF2 = CF2 |
| 3. Polyester | c. CH2 = CHCl |
| 4. Polythene | d. C6H5OH and HCHO |
| 5. Bakelite | e. Dicarboxylic acid and polyhydoxyglycol |
Answer the following.
Draw the structures of polymers formed from the following monomers
H2N–(CH2)5 – COOH
Name and draw structure of the repeating unit in natural rubber.
Identify condensation polymers and addition polymers from the following.
-(CO(CH2)4 - CONH(CH2)6NH-)n
Attempt the following:
What is meant by LDP and HDP? Mention the basic difference between the same with suitable examples.
Answer the following.
Write main specialities of Buna-S, Neoprene rubber?
Nylon 6, 6 is a condensation polymer of hexamethylenediamine and _____________
Write the name of the catalyst used for preparation of high density polythene polymer.
Monomers ethylene glycol and terephthalic acid undergo condensation polymerization to give polymer called ___________
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Write the name and formulae of the monomers used for the preparation of dacron.
Write chemical reactions for the preparation of high-density polythene.
Which among the following polymers is obtained from styrene and 1-3-butadiene?
Which of the following polymer is used in paints?
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.
Identify the INCORRECT match.
Which of the following polymers is obtained from chloroprene?
Which of the following polymers is a heteropolymer?
Which of the following catalysts is used in preparation of terylene?
Which among the following catalysts is used in the preparation of dacron?
Identify the monomers used in the preparation of Novolac.
Identify the catalyst used in the manufacture of high density polythene.
Which among the following monomers is used to prepare Teflon?
Which of the following polymer is used to make blankets?
Which among the following is an example of addition polymer?
Which of the following polymers, need atleast one diene monomer for their preparation?
(i) Dacron
(ii) Buna-S
(iii) Neoprene
(iv) Novolac
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Which of the following polymers is synthesized using a free radical polymerisation technique?
Nylon threads are made of ______.
Which of the following polymers do not involve cross linkages?
Which of the following polymer is used for manufacturing of buckets, dustbins, pipes, etc?
Which among the following polymers has high tensile strength and is used to obtain tyre cords?
Identify the monomer used to prepare neoprene.
Name and draw the structure of the repeating unit in natural rubber.
Name and draw the structure of the repeating unit in natural rubber.
Write the structure of isoprene and the polymer obtained from it.
Write the preparation of viscose rayon.
Another name of terylene is ______.
Name and draw structure of the repeating unit in natural rubber.
Match the following pairs:
| Polymer | Monomer | ||
| (i) | Teflon | (a) | CH2 = CH2 |
| (ii) | PVC | (b) | CF2 = CF2 |
| (iii) | Natural rubber | (c) | Isoprene |
| (iv) | Polythene | (d) | H2C=CHCl |
The monomer used in preparation of teflon is ______.
Name and draw the 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.
