Flory gel point
WebIt further shows that the Flory-Stockmayer theory predicts MWD well for systems below the gel point but starts to fail for systems around or above the gel point. However, for all the systems, the MC method can be used to reliably predict MWD no matter if they are below or above the gel point. Even for a macroscopic system, a converging ... WebMar 1, 2024 · Eventually, the gel point is reached when there is enough of a skeletal structure to allow strain transfer, provided an interface is also established [12]. As the reaction continues, the polymer will be subject to thermal expansions and contractions and the curing process will usually lead to an overall shrinkage as the covalent bonds are …
Flory gel point
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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 … 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.
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. WebBelow the gel point, both Flory-Stockmayer theory and MC simulations can be applied to a system containing only a few hundred to a few thousand monomers but having the same molar ratios of monomers as a macroscopic system to accurately predict MWD. As discussed earlier, the Flory-Stockmayer theory starts to fail when a system approaches …
WebFlory–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.
WebThe growth of the gel fraction in a tetrafunctional system (z = 4, as in silica), calculated from Eq. 12, is shown in Fig. 10.After the gel point, the largest oligomers disappear fastest …
WebFlory–Stockmayer theory explained. 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 … si girls basketball san franciscoWebcases is de ned as the gel point: p c = 1 f 1: (1) Below the gel point p < p c there are only soluble branched polymers and above the gel point p > p c there exists at least one in … the prince of tennis ii u17WebJan 10, 2024 · The Flory-Stockmayer theory represents an advancement from the Carothers equation, allowing for the identification of the gel point for polymer synthesis … the prince of tennis ii: u-17 world cupWebgel point and of the entire molar mass distribution. ESSO LABORATORIES (1940-1943) The onset of World War II greatly increased the ur-gency of development of synthetic rubber and convinced Flory to return to industry. He nevertheless managed to produce some very fundamental results in macromolecular physical chemistry. With John Rehner, Jr., he ... sigis accountWebAug 27, 2012 · For example, a decrease by a factor of 10 in the reactivity of the second hydrogen atom of an amine group to react leads to an increase in an extent of reaction at the gel point (p c) of only 0.022 over the Flory–Stockmayer value of 0.577. sigis backstubeWebNational Center for Biotechnology Information the prince of tennis latinoWebDec 29, 2004 · The status of the gel point equation, advanced by Flory, Stockmayer, and Walling for polyfunctional reactions, is briefly discussed. Two complicating factors in the chain polymerization of divinyl compounds, to which this equation has been applied, are reviewed: the admixture of a monovinyl compound of comparable reactivity, and the … sigi rothemund