Advertisements
Advertisements
Question
Write preparation of low density polythene.
Advertisements
Solution
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
RELATED QUESTIONS
Write any ‘two’ uses of terylene.
Write the structures of the monomers used for getting the following polymers
Melamine – formaldehyde polymer
Answer the following in one sentence.
Define the term: Vulcanization
Answer the following in one sentence.
Identify thermoplastic and thermosetting plastic from the following:
- PET
- Urea formaldehyde resin
- Polythene
- Phenol formaldehyde resin
Answer the following.
Write the reaction of the formation of Nylon 6.
Answer the following.
Write the reaction of the formation of Terylene.
Attempt the following:
Explain the vulcanisation of rubber. Which vulcanizing agents are used for the following synthetic rubber?
a. Neoprene
b. Buna-N
Write the reaction involved in the formation of bakelite.
Answer the following.
Is synthetic rubber better than natural rubber? If so, in what respect?
Nylon 6, 6 is a condensation polymer of hexamethylenediamine and _____________
Write the name of the catalyst used for preparation of high density polythene polymer.
write the structure of the monomer used in natural rubber.
Write the name of one example of each polymer in which following repeating units.
\[\begin{array}{cc}
\ce{(-CF2-CF2-), -[NH-(CH2)5-CO] -, -(CH2-CH-), (-CH2-CH2-)}\\
\phantom{............................}|\\
\phantom{..............................}\ce{CN}
\end{array}\]
Write chemical reactions for the preparation of high-density polythene.
Explain vulcanization of rubber.
Define rubber.
Explain the reactions involved in the preparation of viscose rayon.
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.
Select the CORRECT match for both the polymers.
Which among the following polymers can NOT be remoulded?
Which among the following catalysts is used in the preparation of dacron?
Identify the catalyst used in the manufacture of high density polythene.
Which of the following pair of compounds is used as monomers for bakelite?
Which of the following polymer is used to make blankets?
Which of the following is not a semisynthetic polymer?
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 |
Phenol and formaldehyde undergo condensation to give a polymar (A) which on heating with formaldehyde gives a thermosetting polymer (B). Name the polymers. Write the reactions involved in the formation of (A). What is the structural difference between two polymers?
Which of the following products is formed when benzaldehyde is treated with CH3MgBr and the addition product so obtained is subjected to acid hydrolysis?
Which of the following polymer has ester linkage?
Which of the following polymers is synthesized using a free radical polymerisation technique?
Identify the monomer used to prepare neoprene.
Which of the foolowing polymer is used in the manufacture of insulators.
Answer the following.
Name and draw 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 name of the monomer of natural rubber.
Another name of terylene is ______.
Write the structure of isoprene and the polymer obtained from it.
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.
Identify polyamide polymer from following.
Which from following statements is NOT true regarding neoprene?
Which among the following is a monomer of natural rubber?
