Degree Of Saponification Research Articles

Change in viscosity of oxidized wax upon saponification with aqueous sodium hydroxide solution

1. A study has been made of the change in viscosity of oxidized paraffin in the process of saponification with aqueous sodium hydroxide solution. 2. It has been shown that, with a concentration of sodium salts of fatty acids above 1.1–1.2 moles/liter and a concentration of water below 6–8 moles/liter, there is a sharp increase in kinematic viscosity of the saponified mass. In the other cases, the system viscosity changes almost proportionally to the degree of saponification or to the concentration of sodium salts. 3. On the basis of this study of the change of viscosity upon saponification of the oxidized product, we have drawn a tentative conclusion as to the formation of gels, which produce sharp increases in the viscosity of the system and make it more difficult to process the product.

Synthesis and Properties of Hydrophilic Gels Prepared by Crosslinkage of Poly(vinyl alcohol)

Hydrophilic gels were prepared by the crosslinkage of poly(vinyl alcohol) in suspension state with epichlorohydrin. The permeabilities were determined by eluting water soluble materials, such as poly(ethylene glycol) and dextran, through a column packed with the gels. Excluded molecular weight increased with the decrease of poly(vinyl alcohol) concentration in the aqueous solution and reached to 2X106. A new preparation method of bead-shaped poly(vinyl alcohol) has been developed. The beads of pely(vinyl acetate) were hydrolysed stepweise. Atthe first step, the beads were hydrolysed mainlyi on the surface in aqueous solution of sodium sulfate and sodium hydroxide followed by the addition of a small quantity of methanol, and at the second step, mainly on the inside in the alkaline methanol. The molecular weight and saponification degree of resulted poly(vinyl alcohol) were 67000 and 98.8mol%, respectively. Another type of hydrophilic gel was prepared by the crosslinkage of bead-shaped poly(vinyl alcohol), Tolylenediisocyanate, hexamethylene diisocyanate and epichlorohydrin were used as crosslinkage reagent. These gels could be available for the separation of materials containing various molecular weights. Gel, prepared by the crosslinkage of poly(vinyl alcohol) in the suspension state, was suitable for the separation of polymer, the others for the separation of oligomers. The slope of the calibration curve, α, was affected by the preparation method of the gel.

Long branching in poly(vinyl acetate) and poly(vinyl alcohol). I. Crosslinking and crosslinking cleavage of poly(vinyl acetate)

AbstractA crosslinked network was formed by the reaction of partially saponified poly(vinyl acetate) and toluylene diisocyanate in benzene. The yield of gel was markedly dependent on the degree of saponification and the concentrations of polymer and diisocyanate. Crosslinked poly(vinyl alcohol) was obtained by treating the poly(vinyl acetate) with a catalytic amount of sodium hydroxide in methanol without any change of the urethane crosslinks. The crosslink based on the urethane linkage was quantitatively cleaved by acids, especially by hydrobromic acid, releasing polymers of the same molecular weight as the original.

Monolayers of Poly(methyl acrylate) Saponified Partially in Homogeneous and Heterogeneous Systems

Abstract Poly (methyl acrylate) prepared by radical polymerization of methyl acrylate was saponified partially in acetone-water mixtures (5 : 2 and 100 : 1 by volume), using sodium hydroxide as the catalyst. Saponification in an acetone-water mixture of a 5 : 2 ratio by volume proceeded in a homogeneous state, but the reaction solution of a 100 :1 ratio by volume was in a white-turbid state, in which saponification proceeded in a heterogeneous state. The properties of the monolayers of polymers saponified in different states were studied at the air/water interface by measuring the surface pressure. The limiting areas obtained on distilled water for each polymer saponified in these two systems decreased linearly with an increase in the degree of saponification. However, the monolayers of polymer saponified in a homogeneous system were more stable on sodium chloride solution than those obtained in a heterogeneous system, and gave the limiting areas on solutions above 5% corresponding with the theoretical values calculated from the areas per methyl acrylate and acrylic acid residue and the degree of saponification. This can be explained by the fact that some of the hydrophilic parts of the saponified polymers submerged into the water phase were squeezed out onto the water surface by the salting out effect. On the other hand, those values obtained in a heterogeneous system neither corresponded to the theoretical values nor gave reproducible areas at high concentrations. These facts may be due to the differences in the states of the saponified polymers.

Mechanical Properties of Grafted Paper (Part 2)

The dependence on the degree of saponification of the mechanical properties of polyvinylacetate grafted paper and on the grafting percent of polyvinylalcohol grafted paper was investigated by measuring mechanical strength and dynamic viscoelasticity. The results obtained were as follows.1) Together with saponification, tensile strength and bursting strength increase and especially tearing strength shows remarkable increase.2) Together with saponification, dynamic modulus E' of grafted paper increase and mechanical loss tangent tan δ decrease.3) In the polyvinylalcohol grafted paper, tensile strength increase and tearing strength decrease together with increase of grafting percent.4) The values of dynamic modulus E' increase together with increase of grafting percent.

Mixed Monolayers of Poly(methyl acrylate) and Its Saponified Polymer

Abstract A film balance study of the mixed monolayers with various ratios of poly(methyl acrylate) and its saponified polymer or of the monolayers themselves was carried out on distilled water, and the mixed monolayers were compared with individual monolayers of the saponified polymers. These mixed monolayers expanded more than individual saponified polymers at the same degree of saponification, giving larger limiting areas. Their limiting areas deviated from the linearity between the limiting area and the degree of saponification, in contrast to the fact that the limiting areas of individual monolayers decreased linearly with an increase in the degree of saponification. This fact can be considered to be due to interactions between the side chains of the ploymers.

Development of a New Aqueous Solution Highly Sensitive to Flow Birefringence

An aqueous solution, highly sensitive to flow birefringence and showing Newtonian viscosity is developed from the standpoint of material design to make the flow measurement easier using the flow birefringence method. The highly sensitive solution to flow birefringence is obtained by dissolving Congo Red (CR), which has a large optical anisotropy, into the aqueous solution of polyvinyl alcohol (PVA) of the average degree of polymerization 500 and of the average degree of saponification 98.8%, which can be easily oriented under the action of shear rate. The birefringence and viscosity of PVA–CR aqueous solutions are measured for a range of shear rate from 0 to 2000 s-1. The dispersion of flow birefringence with various wavelengths is also determined. The sensitivity of flow birefringence for shear rate is higher by one or two orders of magnitude than that in aqueous solutions employed by previous investigators. The relation between viscosity and shear rate in the solution is Newtonian.

Monolayer studies on partially saponified poly n-butyl acrylate

A modified Wilhelmy-type film balance was used to investigate monolayer properties of partially saponified poly n-butyl acrylate at the air/water interface. Surface pressure-area isotherms obtained for these saponified polymer monolayers on distilled water showed that the limiting areas are smaller than the theoretical values as calculated from the areas per butyl acrylate and acrylic acid residue. The limiting areas also decrease as the degree of saponification increases. It is thought that some of the hydrophilic parts of the saponified polymers submerge into the water phase, causing the decreases in the limiting areas. Saponified polymer monolayers on sodium chloride solution expanded more than those on water. Their limiting areas increased as the salt concentration was increased. The limiting areas obtained on about 15% salt solution corresponded well to the theoretical values. An explanation is that the submerged hydrophilic residues of the saponified polymers were forced out of the water phase onto its surface via the salting out effect. The ratios of the portion submerging into the water phase and the portion remaining on it were estimated from the degree of saponification and the degree of submergence.

Degree of saponification of oxidation products and the quality of synthetic fatty acids produced

Degree of saponification of oxidation products and the quality of synthetic fatty acids produced

Interaction between polymer and detergent in aqueous solution

The interaction between sodium dodecyl sulfate (SDS) and polyvinyl acetate (PVAc) derivatives, that is, polyvinyl alcohol, polyvinyl acetate, and partially saponified polyvinyl acetate, has been studied in terms of the solubilization of Yellow-OB, viscosity, and dialysis equilibrium. The amount of solubilized Yellow-OB decreases with the decreasing hydrophobic character of the polymer. On the other hand, it can be expected that the reduced viscosity of polymer-SDS and the amount of adsorbed SDS on the polymer will take on a maximum value at some most suitable degree of saponification of PVAc. The state of the polymer-detergent complex in detergent solution is discussed as a function of the hydrophobic character of the polymer.

Studies on Foams. IX. Foaminess and Foam Stability of Polyvinyl Alcohol Solutions

Abstract The foaminess and foam stability of six polyvinyl alcohol solutions, GH–20, GM–14, GL–05, NH–20, NM–14 and NL–05, were measured by the pour test; the foaminess was represented by the height of the foam zone after 1 min., and the foam stability was represented either by the lingering fraction after 35 min. or by the half life of the foam. The foaminess of the partially saponified polyvinyl alcohols was greater than that of the perfectly saponified ones of the corresponding molecular weights. Comparing specimens of the same degree of saponification, the foaminess was the greater, the greater the molecular weight. The foaminess was also the greater, the greater the concentration, except for NH, the fomianess of the latter showing a maximum at about 0.2 g./100 ml. The foam stability of NH and NM was very large, but that of NL was small and showed a maximum at 0.1 g./100 ml. The foam stabilities of GH, GM and GL were small. Comparing the foaminess and the foam stability, these two quantities varied in a parallel manner in the cases of NH, NM, low concentrations of NL, and high concentrations of GM and GL, but in other cases they varied conversely.

The Beater Addition of Polyvinylalcohol Resion

The results of a study of the properties of paper treated with PVA powder by the beater addition are presented.Factors affecting the retention and the strength of the sheets are discussed including the rate of dissolution, particle size of the resin in the range of saponification degree 95.7-99.9%. The absorption water of the sheets are needed more than 60% before drying process.Major advantage was found in the use of PVA powder as beater addition for paper strength.

Methanolysis of triglycerides

SummaryAlkali‐catalyzed methanolysis of fats as a means of preparing methyl esters for analytical purposes has been investigated. Of the various catalysts employed sodium methoxide and ignited potassium carbonate have been found to set free 99–99.5% of total glycerol and to cause the least degree of saponification.

Chemical Substitution in Fibrous Cotton and Resistance of Substituted Cotton to Microbiological Deterioration

The resistance for months to deterioration by microorganisms (in soil burial) of suitably acetylated fibrous cottons, some with only one-third of the hydroxyl groups substituted, depends upon the distribution of the acetyl groups as well as upon the total number of such groups present. Under usual conditions of acetylation, according to the literature, reaction takes place first in the amorphous cellulose, starting at the most accessible places. According to the present ex perimental acetylations and special dyeing tests, the reaction, which is probably confined at first to the amorphous cellulose, takes place along fibers in various segments and throughout cross sections rather than as a layer increasing in thickness from the surface inward. At one-third substitution the amorphous cellulose is converted to triacetate; the cotton fiber still contains about two-thirds of the original cellulose, which is present as crystalline material surrounded by acetylated cellulose. The swelling capacity of the cotton in water is greatly reduced. While the mode of attack by microorganisms is not completely understood, they apparently begin at the most readily accessible amorphous cellulose. From the literature and from the present experiments, protection by partial acetylation is believed to be due to the blocking of hydroxyl groups, the filling of spaces between chains in the amorphous cellulose, and the sup pression of swelling. It represents a general method of rendering cellulose unsuitable, or at least inaccessible, as a food for microorganisms. A relatively low degree of partial saponification may detract greatly from the rot-resistance of a well-protected acetylated cotton owing to the restoration of amorphous cellulose, with loss of blocking groups and a restoration of swelling capacity. Partial methylenation by treatment with formaldehyde may impart a moderate degree of rot-resistance, which seems best explained as being due to the suppression of swelling by cross linking. Formaldehyde-containing resins which impart rot-resistance apparently act similarly. The evidence obtained indicates that the amorphous cellulose is the part which is normally attacked, and that its ability to swell in water may be a more important factor in microbiological attack than is commonly recognized. The use of dyeing has been exemplified for qualitative tests to supplement other evidence regarding substitution and the composition and properties of substituted cottons.