Flory gel point
WebAbstract Using 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. WebMay 12, 2014 · The gel point may be calculated if the chemistry is known (1,2). Gelation in condensation systems like epoxy-amine typically occurs between 50 and 80% …
Flory gel point
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WebAccording to the Flory-Stockmayer Theory, the gel point is closely related to the “branched-point” and the number of its functional groups. And in the three-dimensional … It 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
WebPublished 1 September 1960 Materials Science Journal of Applied Polymer Science Using 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. 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 …
http://polymerdatabase.com/polymer%20chemistry/Gelation.html 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.
WebAt the gel point (critical gel), this long time behavior is self-similar. It follows the typical power law as described by the Chambon-Winter gel equation, G ( t) = St −n, in the terminal zone. The critical relaxation exponent was found to be close to n = 0.5 over a range of stoichiometric ratios and for all precursor molecular weights analyzed.
WebThe classical Flory-Stockmayer treatment of the gel point and the accompanying changes in distributions of species give a basic explanation of the phenomena to which the … crypto currency investment opportunitieshttp://www.nasonline.org/publications/biographical-memoirs/memoir-pdfs/flory-paul.pdf during or while übungenWebDec 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 … crypto currency investment in indiaWebcases 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 … during peeta\u0027s recovery in thirteenWebMar 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 … during or overWebco being the Flory point, and p R the fraction of cyclic bonds to all possible bonds and can be equated with D ring [3]. In this report, the author generalizes, within the framework of … during our stay in europe we visited manyFlory–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. See more The Flory-Stockmayer Theory predicts the gel point for the system consisting of three types of monomer units linear units with two … See more cryptocurrency investment options