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Here t is the time, G is the modulus, and T 0 < T 1 < T 2. Temperature dependence of elastic modulus of a viscoelastic material under periodic excitation. The frequency is ω, G' is the elastic modulus, and T 0 < T 1 < T 2. The time–temperature superposition principle is a concept in polymer physics and in the physics of glass-forming liquids ...
The Flory–Fox equation relates the number-average molecular weight, M n, to the glass transition temperature, T g, as shown below: =, where T g,∞ is the maximum glass transition temperature that can be achieved at a theoretical infinite molecular weight and K is an empirical parameter that is related to the free volume present in the polymer sample.
Bulk polymerization has several advantages over other methods, these advantages are: [1] The system is simple and requires thermal insulation. The polymer obtained is pure. Large castings may be prepared directly. Molecular weight distribution can be easily changed; The product obtained has high optical clarity; Disadvantages: [1]
That is, is the total number of polymer segments (monomers) in the solution, so is the number of nearest-neighbor sites to all the polymer segments. Multiplying by the probability ϕ 1 {\displaystyle \phi _{1}} that any such site is occupied by a solvent molecule, [6] we obtain the total number of polymer-solvent molecular interactions.
Dynamic mechanical analysis (abbreviated DMA) is a technique used to study and characterize materials.It is most useful for studying the viscoelastic behavior of polymers.A sinusoidal stress is applied and the strain in the material is measured, allowing one to determine the complex modulus.
[1] [better source needed] The practical significance of tacticity rests on the effects on the physical properties of the polymer. [not verified in body] The regularity of the macromolecular structure influences the degree to which it has rigid, crystalline long range order or flexible, amorphous long range disorder.
Living polymerization is a popular method for synthesizing block copolymers since the polymer can be synthesized in stages, each stage containing a different monomer. Additional advantages are predetermined molar mass and control over end-groups.
In polymer chemistry, emulsion polymerization is a type of radical polymerization that usually starts with an emulsion incorporating water, monomers, and surfactants.The most common type of emulsion polymerization is an oil-in-water emulsion, in which droplets of monomer (the oil) are emulsified (with surfactants) in a continuous phase of water.