Flory equation gel point
Web2. Flory Theory. Flory treated the question of equilibrium conformation of real chains using a mean field approach. The equilibrium size is set by a balance between excluded volume which tends to expand the chain size, and a restoring force due to loss of conformational entropy due to swelling. The energetic contribution due to excluded volume ... 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 …
Flory equation gel point
Did you know?
WebIf adipic or isophthalic acid is used as the dibasic acid, the gel point equation deduced by Flory's original method, which takes no account of reactivity differences, may be used. In such a case the difference between the observed and calculated gel point is about 5% when the polyhydric alcohol used is trifunctional and 8–9% when the ... Flory–Stockmayer theory is a theory governing the cross-linking and gelation of step-growth polymers. 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 … See more Gelation occurs when a polymer forms large interconnected polymer molecules through cross-linking. In other words, polymer chains are cross-linked with other polymer chains to form an infinitely large molecule, … See more In creating the Flory-Stockmayer Theory, Flory made three assumptions that affect the accuracy of this model. These assumptions were: 1. All functional groups on a branch unit are equally reactive 2. All reactions occur between A and B See more The Flory-Stockmayer Theory predicts the gel point for the system consisting of three types of monomer units linear units with two A-groups (concentration See more
WebSep 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. 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 …
WebIt is important to realize that the value for the gel point predicted by Carothers is always larger than that of Flory and Stockmayer, i.e. 2/ϕ ≥ 1/(ϕ − 1), ∀ ϕ ≥ 2. Another consequence from this inequality is given by the comparison of … Webbiphasic system, a single glass transition, a miscible system following the Flory-Fox equation. Further support for miscibility would come from microscopy and scattering (neutron, x-ray and light can all be used to characterize miscibility). Generally, thermal analysis is the easiest and most available of techniques to apply to a sample and
Weboccurs in excess of Flory−Stockmayer gel point; the excesses are 0.09−0.15 in extent of reaction. λ 0 is determined from the gel point data through the p c−λ 0 relationship developed in the first part of this study, where the schemes of unequal reactivity and the states of reaction for POP diamine unit are incorporated.
fishkill weather 12524WebCalculation of Swelling for a Gel. The Flory-Rehner Equation (Flory's first book) describes swelling of network polymers as a function of the enthalpic interaction parameter between the polymer unit and the solvent, c, the molar volume of the solvent, V 1, and the molecular weight between crosslink sites, n. where v 2 is the volume fraction of polymer … fishkill weather radarWebJan 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 … can child support be waived by a parent in njWebFirst proposed in 1950 by Paul J. Flory and Thomas G. Fox while at Cornell University. Proper noun . Flory-Fox equation In polymer chemistry, a simple empirical formula that relates molecular weight to the glass transition temperature of a polymer system. can child support be taxedWebJan 1, 2002 · Abstract. Recent developments in gel research are reviewed with emphasis on the gel point problem. We will describe in due course how the gel point equation can be deduced from first principles. First we review briefly the industrial development of gel science in Japan (Sect. 1) and a central aspect of the classical theory of gelation (Sect. 2). fishkill weather todayWebJan 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 … can child support be taken from ssi in texasWebThree-dimensional condensation of silicon-containing alcohols with tetrafunctional acid esters ☆ can child support continue through college