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The degree of polymerization, or DP, is the number of monomeric units in a macromolecule or polymer or oligomer molecule. [1] [2] [3]For a homopolymer, there is only one type of monomeric unit and the number-average degree of polymerization is given by ¯ ¯ = ¯, where ¯ is the number-average molecular weight and is the molecular weight of the monomer unit.
The simplest case refers to the formation of a strictly linear polymer by the reaction (usually by condensation) of two monomers in equimolar quantities. An example is the synthesis of nylon-6,6 whose formula is [−NH−(CH 2) 6 −NH−CO−(CH 2) 4 −CO−] n from one mole of hexamethylenediamine, H 2 N(CH 2) 6 NH 2, and one mole of adipic acid, HOOC−(CH 2) 4 −COOH.
Compatibility is a term used by geochemists to describe how elements partition themselves in the solid and melt within Earth's mantle.In geochemistry, compatibility is a measure of how readily a particular trace element substitutes for a major element within a mineral.
The UCST and LCST of polymer mixtures generally depend on polymer degree of polymerization and polydispersity. [6] The seminal statistical mechanical model for the UCST of polymers is the Flory–Huggins solution theory. [7] By adding soluble impurities the upper critical solution temperature increases and lower critical solution temperature ...
A polymer can be described in many ways: its degree of polymerisation, molar mass distribution, tacticity, copolymer distribution, the degree of branching, by its end-groups, crosslinks, crystallinity and thermal properties such as its glass transition temperature and melting temperature.
As a result of this, methods which rely on resolution of the end-group signal are mostly used for polymers of low molecular weight (roughly less than 20,000 g/mol number-average molecular weight). [8] By using the information obtained from the integration of a 1 H NMR spectrum, the degree of polymerization (X n) can be calculated.
Flory postulated that his treatment can also be applied to chain-growth polymerization mechanisms, as the three criteria stated above are satisfied under the assumptions that (1) the probability of chain termination is independent of chain length, and (2) multifunctional co-monomers react randomly with growing polymer chains.
In polymer chemistry, polymerization (American English), or polymerisation (British English), is a process of reacting monomer molecules together in a chemical reaction to form polymer chains or three-dimensional networks. [1] [2] [3] There are many forms of polymerization [4] and different systems exist to categorize them. IUPAC definition for ...