Table of Contents
- 1 Which method usually used to measure the degree of polymerization of a polymer?
- 2 What is the formula of polymerization?
- 3 What is degree of polymerization?
- 4 What is degree of polymerization used for?
- 5 What is polymerization temperature?
- 6 What is thermodynamics of polymerization?
- 7 How do I calculate the enthalpy of reaction?
- 8 How do I calculate the molecular formula?
Which method usually used to measure the degree of polymerization of a polymer?
It is typically determined by measurements of Rayleigh light scattering by the polymer.
What is the formula of polymerization?
Some Common Addition Polymers
| Name(s) | Formula | Monomer |
|---|---|---|
| Polyethylene high density (HDPE) | –(CH2-CH2)n– | ethylene CH2=CH2 |
| Polypropylene (PP) different grades | –[CH2-CH(CH3)]n– | propylene CH2=CHCH3 |
| Poly(vinyl chloride) (PVC) | –(CH2-CHCl)n– | vinyl chloride CH2=CHCl |
| Poly(vinylidene chloride) (Saran A) | –(CH2-CCl2)n– | vinylidene chloride CH2=CCl2 |
How do you determine the degree of polymerization of cellulose?
The degree of polymerization of cellulose is calculated from the intrinsic viscosity of solutions prepared by dissolving cellulose in a suitable solvent, such as CED or cadoxen.
How do you calculate the heat of polymerization?
The heats of polymerization for a number of monomers are shown in the Appendix. Since AHp = AE – P AV, if the volume change can be neglected, the heat of polymerization becomes equivalent to the change in internal energy of the molecule.
What is degree of polymerization?
The degree of polymerization (DP or Xn) is defined as the number of monomer units in the polymer. It is calculated as the ratio of molecular weight of a polymer and molecular weight of the repeat unit. Number average DP and weight average DP are the two main types used for measuring the DP.
What is degree of polymerization used for?
The term degree of polymerization is defined as the number of repeating units in a polymer molecule. In some cases, this term is used to express the number of monomer units in an average polymer molecule. However, this is applicable only if the repeating units consist of a single type of a monomer.
What is the degree of polymerization of polyester?
The degree of polymerization of polyester polymer is controlled, depending on its end-uses. Polyester polymer being to be used in industrial fibres has higher degree of polymerization, high molecular weight and high viscosity. “The normal molecular weight ranges between 15,000 and 20,000”.
What is crystallinity and degree of polymerization in cellulose?
Degree of polymerization is not related to crystallinity of cellulose. Degree of polymerization can be same in both crystalline and amorphous region of cellulose however crystallinity is the factor of packing of cellulose chains which further depends upon hydrogen bonding.
What is polymerization temperature?
From Wikipedia, the free encyclopedia. Ceiling temperature ( ) is a measure of the tendency of a polymer to revert to its constituent monomers. When a polymer is at its ceiling temperature, the rate of polymerization and depolymerization of the polymer are equal.
What is thermodynamics of polymerization?
Polymerization is the process of taking individual monomers and enchaining them into a macromolecule. Thermodynamically, there are always two factors to consider in a reaction: enthalpic contributions and entropic contributions. ΔG = ΔH – TΔS.
How do you find the degree of polymerization of polystyrene?
Therefore, the average degree of polymerization by weight of a sample of PS with a molecular weight Mw = 5.4 106 g / mol, is: xw = 5.4 x 106 / 104 = 5.2 x 104.
What is molecular weight and degree of polymerization?
The degree of polymerization (\\(DP\\)) in a polymer molecule is the number, n, of repeating units in the polymer chain . The molecular weight of a particular polymer molecule is a product of the degree of polymerization and the molecular weight of the repeating unit .
How do I calculate the enthalpy of reaction?
If calculating the enthalpy of a chemical reaction involving multiple units of a compound, multiply the ΔHf values by the necessary moles. When this is done, you can complete the Hess’s Law equation to calculate the enthalpy of the chemical reaction.
How do I calculate the molecular formula?
Divide the number of grams of each element in the sample by the atomic weight of the element (from the periodic table) to find the number of moles. Divide this number by the molecular weight of the empirical formula to find the number of empirical formula units that make up the compound.
What are some examples of polymerization?
The two major types of polymerization are addition polymerization and condensation polymerization. Addition Polymerization. Polymerization that occurs through the coupling of monomers using their multiple bonds is called addition polymerization. The simplest example involves the formation of polyethylene from ethylene molecules.