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11 votes
1 answer
1k views

Can a long polymer chain interact with itself via van der Waals forces?

It is known that van der Waals interaction is an intermolecular forces. So is it possible that a long polymer chain interacting with itself via non-bonded interactions (such as van der Waals forces / ...
Rheologist Ph.D.'s user avatar
2 votes
1 answer
127 views

Relating properties and structures of polymers

Why would it be more favorable for a polymer designer to design copolymers with irregular chain structures, rather than design homopolymers? Hint: Discuss intermolecular bonds I understand that ...
Ella Lewis's user avatar
0 votes
1 answer
174 views

What are the intermolecular forces between polychloroethylene?

Does polychloroethylene have only van der Waals/London forces between its molecules? Surely, if all the chlorine atoms are on one side, due to the fact that chlorine is more electronegative than ...
Anna's user avatar
  • 11
1 vote
2 answers
7k views

Why does branching decrease density and melting point?

The general explanation given is that the chains are further apart, so the intermolecular forces are less, and as they are further apart, they occupy more volume, and the density is lesser. But the ...
John's user avatar
  • 495
2 votes
2 answers
458 views

Why is polymer B more dense than polymer A?

The official solution is that A has branched / side chains, weak Van der Waals forces between the polymer chains, less compact packing than B, and large inter-chain distances. B has no branched chains,...
John's user avatar
  • 495
2 votes
1 answer
2k views

How does cross-linking between polymer chains increase the melting point of the polymer?

https://i.sstatic.net/uUcQr.jpg Suppose we have this polymer chain. Now, we cross link some chains ( not all ) , so some chains get linked, and others remain as they are. What we now have is a '...
John's user avatar
  • 495
5 votes
3 answers
6k views

Why plastic sheets contract when heated?

Why do thin plastic sheets contract when heated, contradictory to the behavior of most other materials ? What are the things going on at the molecular level ?
Abhirikshma's user avatar
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