Flory equation gel point
WebJun 11, 2024 · The Carothers equation can be used to estimate the conversion needed to reach the gel point in condensation polymerization involving monomers with functionalities higher than 2. With the assumption that the gel point is reached when practically all molecules of the limiting monomer have reacted, the requisite fractional conversion of … http://matse.u-fukui.ac.jp/~bussei/res-activity/Measurements%20of%20Gel%20points%20and%20Analyses%20on%20Ring%20Structures-Macromolecules-2012.pdf
Flory equation gel point
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http://polymerdatabase.com/polymer%20chemistry/Gelation.html WebSep 17, 2024 · To explore the physical properties of hydrogels in terms of statistical thermodynamics, the mean-field Flory–Huggins–Rehner theory has long been used with various analytical and numerical modifications. Here, we suggest a novel mathematical model on the phase transition of a biological hybrid gel that is sensitive to ambient …
WebThree-dimensional condensation of silicon-containing alcohols with tetrafunctional acid esters ☆ WebGelation in Polymerization. The classical theories of Carothers, Flory and Stockmayer 1-5 describe the conversion of growing polymers to insoluble gels which occurs through crosslinking. All three theories use a statistical approach and assume that polymers approach infinite size at the gel point, i.e. they become one gigantic molecule.
WebDec 14, 2024 · Abstract and Figures. The number-average functionality is proposed a simplified equation which can be used to predict the reaction progress of the stepwise polymerization expediently. According to ... WebThe weight fraction distribution is the fraction of x-mers in a system and the probability of finding them in terms of mass fraction. = = = Notes: M o is the molar mass of the repeat unit,; N o is the initial number of monomer molecules,; and N is the number of unreacted functional groups; Substituting from the Carothers equation = = We can now obtain: = …
WebUsing Flory's basic method, an equation is derived for the gelation point of oil-modified alkyd resins in which account is taken of the different reactivities of the various carboxyl groups. The resultant modified equation is useful when phthalic anhydride is used as the dibasic acid because of the widely differing carboxyl group reactivities which occur in this …
WebJan 10, 2024 · The Flory-Stockmayer theory represents an advancement from the Carothers equation, allowing for the identification of the gel point for polymer synthesis not at stoichiometric balance. The theory was initially conceptualized by Paul Flory in 1941 [1] and then was further developed by Walter Stockmayer in 1944 to include cross-linking … space invaders showWebA branched oligomer becomes a crosslinked polymer when the reactive extent reaches the gel point Pc, and the formula used to calculate the gel point Pc is well described by Flory-Stockmayer Theory. We have therefore derived the formula to calculate the Pc for our own case, Where the parameters are: Pc: The gel point, at which the gel forms. space invaders slot machineWebJan 1, 2001 · Flory proposed the concept of “infinite molecular weight with respect to the weight average molecular weight,” which is the concept still in use. ... Therefore, from Eq. (lb), the following equation is derived: Pnp.gel • Pgel-2 (at gelation) (3) Consequently, it becomes apparent that the concept of the necessity of two crosslink points ... teams name for gameWebSep 12, 2024 · KP2. Kinetics of Step-Growth Polymerization. It is important to understand how reactions proceed over time. This information can tell us how long it will take for a polymer to reach an optimum length. It can also provide insight into how the polymerization occurs, just as kinetics can provide insight into other reaction mechanisms. team snacks for sportsIt is important to be able to predict the onset of gelation, since it is an irreversible process that dramatically changes the properties of the system. According to the Carothers equation number-average degree of polymerization is given by where is the extent of the reaction and is the average functionality of reaction mixture. For the gel can be considered to be infinite, thus the critical extent of the reaction at the gel point is found as space invaders scratcherWebJan 1, 2004 · That equation can also be used to estimate the gel point (state of conversion at which crosslinks begin to form) in polymerization of monomers with more than two functional groups per molecule. If the monomers are bifunctional and statistical growth can be assumed, the mole fractions of successive polymer molecules (with increasing … space invaders soundsWebFlory’s theory treated these two entropic terms in the Gibbs free energy on an equal ... forward osmosis, (4) the antifouling characteristics of hydrogels, and (5) melting point suppression and boiling point elevation, and solubility of salts in hydrogels. ... Most applications of these thermodynamic models focused on the gel swelling ratio ... space invaders snes