Flory gel point
WebSep 1, 2012 · Typically, the classical Flory-Stockmayer (FS) theory 11,12 or an equivalent mean field model 13,14 is taken for a first estimate based upon an ideal system whereby both intra-molecular reactions... 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
Flory gel point
Did you know?
WebThis number diverges at p c = 1 / (f - 1) which is Flory's predicted gel point. In the case of AB f-1 monomers, this is the point at which all A functionalities have reacted, i.e., (f - 1) … WebMar 11, 2024 · 7.2.1 Flory-Stockmayer Model. The thermodynamics understanding of gelation is the oldest. It results from developments by Flory (1941, 1953) and Stockmayer and first concerned organic materials.In these first studies, gelation designates the transformation of a liquid, by chemical reactions, to a material presenting the …
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 … WebGel point, the transition point from a polymer solution to gel, is a function of the extent of reaction or the fraction of functional groups reacted. Gelation time is the time interval between the onset of reaction– by heating, addition of catalyst into a liquid system, etc.– and gel point. ... The Flory model was further refined by ...
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. WebNational Center for Biotechnology Information
WebStatistical network models were first developed by Flory (Flory and Rehner, 1943, Flory, 1953) and Stockmayer (1943, 1944), who developed a gelation theory (sometimes referred to as mean-field theory of network formation) that is used to determine the gel- point conversions in systems with relatively low crosslink densities, by the use of ...
WebJan 1, 2002 · Under these assumptions, we can derive analytical expressions for gel points as functions of γ (= 1/C: the reciprocal of an initial monomer concentration), κ (mole ratio of B-type functional units to A-type functional units), and d (space dimension); that is, D c = G ( … candlewood suites santa mariaWebFlory–Stockmayer theory is a theory governing the cross-linking and gelation of step-growth polymers. [1] 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. [1] fish serving size graphicWebFlory–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. fish serving sizeWebIf 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 … candlewood suites san marcos txWebPublished 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. candlewood suites sayre an ihg hotelWebAccording 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 … fish set aliasWebAug 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. candlewood suites sandestin