Polymer Physics: molar mass, polymerization

In summary, the given scenario describes a 100g chunk of a polybutadiene network, which is a single molecule with all monomers covalently bonded together. The molar mass of the monomer is 54g/mol. To determine the number of monomers in the macromolecule, the degree of polymerization needs to be calculated first.
  • #1
gokies

Homework Statement


Consider a “true macromolecule” - a chunk of polybutadiene network
of mass 100g. How many monomers all covalently bonded together
does it contain if the molar mass of the monomer is
Mmon= 54g/mol?
What is the molar mass of this macromolecule?

Homework Equations



Molar mass of polymer = polymerization * Molar mass of monomer

The Attempt at a Solution



It seems I have two unknowns in my equation of three variables. The biggest issue is that I'm unsure what the relevance of the 100g sample is. None of the textbook examples or online examples that I've found are structured this way. They always give a molar mass/molecular weight of the polymer.

100g / 54g/mol says that 1.96 moles of the monomer can "fit" into the 100g sample of the polymer. Though I'm not sure how relevant that is. Based on the order of the two questions, it seems I need to find the degree of polymerization first.
 
Physics news on Phys.org
  • #2
gokies said:
Consider a “true macromolecule” - a chunk of polybutadiene network of mass 100g.
My reading of this is that the 100g chunk is a single molecule (all the monomers are bonded to each other).
 
  • Like
Likes Chestermiller
  • #3
"Network" would imply that it is cross-linked, though I'm not sure if that's what they really mean or they're just being sloppy. Certainly a linear polymer with a degree of polymerisation of 1024 would be very unusual.
 

1. What is molar mass in polymer physics?

Molar mass in polymer physics refers to the mass of one mole of a polymer molecule. It is typically measured in grams per mole (g/mol) and is an important factor in understanding the physical properties of a polymer.

2. How is molar mass calculated for polymers?

Molar mass for polymers can be calculated by multiplying the number of repeating units in the polymer chain by the molar mass of each repeating unit. This can be determined through various methods such as gel permeation chromatography or mass spectrometry.

3. What is polymerization in polymer physics?

Polymerization in polymer physics is the process of joining together monomers (smaller molecules) to form a long chain polymer molecule. This can occur through various methods such as addition polymerization, condensation polymerization, or ring-opening polymerization.

4. How does polymerization affect the molar mass of a polymer?

The process of polymerization directly affects the molar mass of a polymer. As more monomers are added to the polymer chain, the molar mass increases. The type of polymerization also plays a role in determining the final molar mass of a polymer.

5. What is the significance of molar mass in polymer physics?

Molar mass is a crucial factor in understanding the physical properties of a polymer. It can affect properties such as melting point, solubility, and mechanical strength. Additionally, molar mass helps to characterize and classify different types of polymers.

Similar threads

  • Engineering and Comp Sci Homework Help
Replies
1
Views
2K
  • Biology and Chemistry Homework Help
Replies
4
Views
12K
  • Biology and Chemistry Homework Help
Replies
7
Views
4K
  • Biology and Chemistry Homework Help
Replies
1
Views
4K
  • Biology and Chemistry Homework Help
Replies
4
Views
4K
  • Biology and Chemistry Homework Help
Replies
6
Views
3K
  • Biology and Chemistry Homework Help
Replies
2
Views
7K
  • Biology and Chemistry Homework Help
Replies
2
Views
2K
Replies
50
Views
5K
  • Science and Math Textbooks
Replies
19
Views
17K
Back
Top