Die Kinetik polymerer Aldehyde, VII. Mitteil.: Die Verseifungsgeschwindigkeit der Formaldehydacetale

Löbering, J.; Fleischmann, Andreas

doi:10.1002/cber.19370700815

Cited by 9 publications

(1 citation statement)

References 6 publications

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“…This is shown in Table I and graphically represented in Fig. 1 Accordingly, there appears to be a direct relationship between the clata given by Skrabal and Eger (17,12) on the acidic saponification of the acetals of some of the alcohols under discussion and their retarding effect. The slower the hydrolysis of an acetal, the greater the retarding effect of the reIated alcohol on the uncatalyzed resorcinol-formaldehyde condensation.…”

Section: Comparison With Acetalization Reactionsupporting

confidence: 53%

Influence of Alcohols Upon the Uncatalyzed Reaction Between Resorcinol and Formaldehyde

Raff¹,

Silverman²

1951

Can. J. Chem.

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The rate of the conderisatior~ o l an uncatalyzed, eq~~in~olecular s o l~~l i o n of resorcinol and formaldehyde in water was determined a t 60°C. By replacing a portion of the water in this systern with aliphatic alcohols, a reduction in the ratcs of corldensation was noted a t the same temperature. Ho\vever, these reaction rates were found to vary widely among themsel\-es, depending 011 the alcohol used. These results are explained under the assumption of the intermediate forn~ation of herniacetals from the free formaldehyde and the alcohols. The retarding effect of these alcohols on the resorcinol-formaldehyde condensation is inversely related to their different tendency to form esters with acids, or acetals w~t h aldehydes, as reported by other authors. The gencral ilnportance of the formation of he~lliacetals is emphasized where forrnaldehycle is applied in the presence of alcohols. Discussion of Previous ExperimentsPrevious work (15) on the lti~letics of the i~ncatalyzed reaction of resorcinol and for~llaldehyde had shown the considerably higher reactivity of resorcinol as compared to phenol and to alkylated monophenols. For the various ternperatures ancl the different ratios of resorcinol t o formaldehyde which were investigated, a first ordcr rcaction rate constant served best t o represent the experimental data. These co~ldensations had been studied on solutions of resorcinol in dioxane and water, to which the calculated amounts of aqueous formaldehyde solutions were added. The charges were prepared in such a way t h a t the combined weights of resorcinol plus forn~aldehyde (as C H 2 0 ) represented 40% of the total weight of the solutions; the dioxane amounted to 2G.7y0; 33.3% water was present, partially introduced as part of the aqueous formaldehyde solutio~~. These mixtures were reacted in a resin flask kept in a constant temperature bath, and the progress of the reaction determined from the gradual decrease in free forn~aldehyde on san~ples removed during the experiment. Influence of SolventsSince i t appeared of interest to learn the influence of solve~lts upon the reaction rate of the uncatalyzecl resorcinol-formaldel~yde condensation, equinlolecular mixtures of resorcinol and formaldehyde were reacted a t GO°C., in which the dioxane in the above formulation was replaced by various aliphatic alcohols. One experiment was also carried out in an all aqueous mecliu~n, replacing the dioxane by water. As found in dioxane, a first order reaction rate constant served best to represent the experinlental data.

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Section: Comparison With Acetalization Reactionsupporting

confidence: 53%

Influence of Alcohols Upon the Uncatalyzed Reaction Between Resorcinol and Formaldehyde

Raff¹,

Silverman²

1951

Can. J. Chem.

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The resilience of chemically modified cottons. II. Reactions of cellulose with formaldehyde under acid conditions

Dusenbury

Pacsu

Teulings

et al. 1961

J of Applied Polymer Sci

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A study has been made of the reactions of cellulose with formaldehyde under acid conditions, where the fabrics are baked at elevated temperature. These treatments have involved cotton cellulose in a “dry” or relatively unswollen state and have resulted in the treated fabrics exhibiting improved crease rccovery both dry and wet. It has been found that boiling 1% acetic acid solution reduces the acetal contents of the treated fabrics and causes corresponding decreases in both dry and wet crease‐recovery improvement. The reproducibility of these treatments, with respect both to extents of formaldehyde incorporation and to dry and wet crease recovery, is found to be very good within a single treatment and, more importantly, tietween different treatments carried out under the same conditions. The rates of acetal removal by the boiling 1% acetic acid and the relationships between acetal content and crease‐recovery improvement have been found to be fairly complex. A study has also been made of the rates of acetal removal by boiling 1% acetic acid for samples of cotton card sliver treated with acid and subsequently heated in sealed tubes with paraformaldehyde. The rates of acetal removal in this case have been observed to be qualitatively similar to those observed for treated fabrics. The implications of these findings are discussed.

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Influence of chain length on the rate of hydrolysis of polyoxymethylene ethers

Stanonis

King

Vail

1972

J of Applied Polymer Sci

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SynopsisFour series of polyoxymethylene ethers (polyformals) [RO(CH20)&] where R is isopropyl, ethyl, methyl, or methoxyethyl and n = 1-3 have been prepared, examined by GLC, separated by fractional distillation, and characterized by NMR. Rate constants for the aqueous acid hydrolysis of all the compounds have been determined. The isopropyl series appears to be a special case, and as reported in the literature (but in aqueous dioxane), all members of this series hydrolyze a t the same rate. In the other series, there is a definite increase in rate, which never exceeds fourfold, in going from n = 1 to n = 2. This increase differs considerably from the 100-fold increase reported by others in going from CII30CH20CHa to CH,O(CHzO)?CH3. In all series, the n = 3 compound hydrolyses at practically the same rate as the n = 2 compound.

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Die Kinetik polymerer Aldehyde, VII. Mitteil.: Die Verseifungsgeschwindigkeit der Formaldehydacetale

Cited by 9 publications

References 6 publications

Influence of Alcohols Upon the Uncatalyzed Reaction Between Resorcinol and Formaldehyde

Influence of Alcohols Upon the Uncatalyzed Reaction Between Resorcinol and Formaldehyde

The resilience of chemically modified cottons. II. Reactions of cellulose with formaldehyde under acid conditions

Influence of chain length on the rate of hydrolysis of polyoxymethylene ethers

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