Adipic acid polyesterification

A short chapter on polycondensations is also included. In addition to the classic work of Carothers, significant work by Raff and Dostal is mentioned. In addition to the groundbreaking theoretical work discussed above. Raff mentions the experimental work of Flory on diethylene glycol-adipic acid polyesterification. 

Table I. Kinetic orders of various non-catalyzed polyesterifications of adipic acid with aliphatic primary diols. The first figure in the 3rd column is the overall order and figures in brackets denote orders with respect to acid and alcohol. 2 + 3 means that kinetics has been treated as resulting from the superposition of two reactions with orders 2 and 3, respectively. The range of conversion which has been studied is given in the 2nd column for instance, 80-100 means that kinetics has been studied between 80 and 100% conversion...

The ATO Chemie process involves the formation of an adipic acid-capped hard segment block of poly(ll-aminoundecanoic) of molecular weight 800-1500, joined with a soft segment of polyol in a polyesterification process. 

In the polyesterification process p is directly calculated from the carboxyl group titer. Results for the polyesterification reaction between diethylene glycol and adipic acid at 166° and 202°C are plotted in Fig. 3 in accordance with the third-order equation (8). For comparison purposes, the course of the non-polymer-forming reaction of diethylene glycol with the monobasic acid, caproic, is also shown. Eq. (8) is not obeyed from zero to 80 percent esterification [l/(l—p) =l to 25], as is shown by the curvature over this region. From 80 to 93 percent esterification the reaction appears to be third order. The non-polymerforming esterification of diethylene glycol with caproic acid (and other... 

Fig. 2-1 Third-order plot of the self-catalyzed polyesterification of adipic acid with diethylene glycol at 166°C. After Solomon [1967] by permission of Marcel Dekker, New York) from the data of Flory [1939] (by permission of American Chemical Society, Washington, DC).

Statistical kinetics of polyesterification of adipic acid with pentaery thritol and trimethylolethane. J. Chem. Soc. 1967, 1. 

In the presence of an added catalyst such as p-toluenesulphonic acid, simple esterification reactions and polyesterification reactions are second order [48]. Thus the kinetics of the catalysed reaction of lauric acid and lauryl alcohol in a medium of lauryl laurate closely parallels those of the polymer-forming reaction between adipic acid and 1,10-dodecanediol in a medium of polyester product. Second-order rate coefficients for the two reactions were [35], respectively, 45x10 equiv kg" sec and 16 X 10" equiv kg" sec . 

The experimental reports on gel point determinations are scarce. The first reliable experiment was reported by Flory, who carried out this in 1941 in the polyesterification of a pentaerythritol - adipic acid mixture (R- A4+R-B2) (Fig. 17) in order to test his own theory. In 1945, the gelation of the same system was reinvestigated in a more systematic way by Wile [81] he observed that experimen-... 

Polyamide formation is entirely analogous to polyesterification and all of the earlier considerations apply. For polymers of the type AABB, nylon-6,6 is the best example. Thus poly(hexamethylene adipamide) is formed by the condensation reaction between hexam-ethylene diamine and adipic acid ... 

The rate constants obtained by the above method for uncatalyzed polyesterification of adipic acid with different glycols are shown in Table 5.2. The Arrhenius parameters A and E of the equation k — Aexp —E/RT) are also presented in Table 5.2 for those reactions that have been studied kinetically at more than one temperature. Note that the concentration units of the rate constants are in terms of moles per kilogram, which is a more convenient measure of concentration than the usual moles per liter because the volume of the system decreases significantly due to reaction. 

Figure 5.1 Plot of Eq. (5.30) for the later stages of uncatalyzed polyesterification of adipic acid and 1,10-decamethylene glycol (Problem 5.1). (Note that the reaction time of zero corresponds to 82% conversion of the original COOH groups present.)...

Table 5.2 Kinetic Parameters for Uncatalyzed Polyesterification of Adipic Acid with Several Glycols ...

Problem 5.29 A polyesterification system consists of diethylene glycol (1 mol), tricarballylic acid (0.144 mol), and adipic acid (0.784 mol). What weight fraction of the polymeric mixture has (a) only linear chains, and (b) 5 or less chains per molecule at 40% conversion Obtain an estimate of the corresponding values at the gel point, disregarding intramolecular reactions. 

A polyesterification batch consists of tricarballylic acid (1 mol), adipic acid (4 moles), and diethylene glycol (5.5 moles). Calculate (a) the gel point conversion and (b) the weight fractions of polymeric mixture containing, respectively, 1, 3, and 5 chains per molecule at this conversion. 

Figure 5.1 Plot of Eq. (5.15) for the later stages of uncatalyzed polyesterification of adipic acid and...

FIGURE 2.3(a) Self-catalyzed polyesterification of adipic acid with ethylene glycol at 439 K (b) polyesterification of adipic acid with ethylene glycol at 382 K, catalyzed by 0.4 mol percent of /7-toluene sulfonic acid. (Data from Flory.)... 

For the polyesterification reaction between diethylene glycol and adipic acid, calculate the number-average molecular weight of the polyester that is formed when the extent of reaction p is equal to 0.90. Note that, for condensation polymers that are synthesized from two reactants, half the average-molar-mass of the repeat unit is used to calculate the degree of polymerization. 

UPRs based on a mixture of maleic anhydride, phthalic anhydride and adipic acid in a molar ration of 1 2 2 were prepared in the presence of the polyesterification catalysts, i.e. lead dioxide, p-toluenesulfonic acid monohydrate and zinc acetate dihydrate, and next crossHnked with styrene by using MEKP as the initiator and cobalt naphthenate (CoNp) as the promoter [197]. Most often, the catalysts used in the polyesterification process cannot be easily separated from the polyester, thus the effect of the residual catalysts on the curing process and color of the cured polyester resin should be taken into account. It was shown that the residual catalyst could affect the curing reaction even in a small amount (Table 28), increasing the activation energy a, frequency factor ko and the reaction order x. 

Figure 13.11 Polyesterification of Adipic Acid with Two Polyalcohols, Catalyzed with p-Toluene Sulfonic Acid. The left axis shows the value of 1 /(1 - p) where p Is the fraction of carboxyl groups that have reacted. The right axis Is labeled with the percent of original carboxyl groups that have reacted. From H. R. Allcock and F. W, Lampe, Contemporary Polymer Chemistry Prentice Hall, Englewood Cliffs, NJ, 1981, p. 254.

The acid-catalyzed polyesterification of ethylene glycol and adipic acid has been studied by Flory. The data are plotted in Figure 3.5. This figure also reveals that Eq. (3.7.8) holds after about 80% conversion. More extensive experimental data [24-27] do not, however, confirm Flory s conclusions. It has been argued that only a limited amount of adipic acid dissociates in ethylene glycol (0.390 moles per mole ethylene glycol), and only this acid contributes to the catalysis in the polymerization without strong acid. Hence, instead of Eq. (3.7.2), it has been proposed that... 

Kinetic studies on the bulk polyesterification of a,o-dicarboxy poly(hexamethylene adipate) with a,polymeric medium. Solomon s mechanism1 can be considered as reasonable. 

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