US3854868A

US3854868A - Non-aqueous process for reacting sultones with cellulosic materials and the product produced

Info

Publication number: US3854868A
Application number: US00306770A
Authority: US
Inventors: T Ward; R Benerito; R Berni
Original assignee: US Department of Agriculture USDA
Current assignee: US Department of Agriculture USDA
Priority date: 1972-11-15
Filing date: 1972-11-15
Publication date: 1974-12-17
Anticipated expiration: 1991-12-17

Abstract

Cellulose is converted into sodium cellulosate by reaction of the preswollen cellulose with sodium alkoxide and then washed with tertiary butanol prior to reaction with hydrocarbon sultone in tertiary butanol. More sulfur is added by this procedure than when water is present. The sultone solution is not contaminated by base and may be used repeatedly. This reuse of reactants reduces costs and diminishes pollution. The resultant products have active acidic sites, thus making them suitable intermediates for other reactions.

Description

United States Patent [191 Ward et al.

[111' 3,854,868 [451 Dec. 17, 1974 NON-AQUEOUS PROCESS FOR REACTING SULTONES WITH CELLULOSIC MATERIALS AND THE PRODUCT PRODUCED [75] Inventors: Truman L. Ward; RuthR. Benerito,

' both of New Orleans; Ralph J.

Berni, Metairie, all of La.

[73] Assignee: The United States of America as represented by the Secretary of Agriculture, Washington, DC.

22 Filed: Nov. 15, 1972 21 Appl. No: 396,770

[52] U.S. Cl. 8/116 R, 8/130.1 [51] Int. Cl..... D06m l/00 [58] Field of Search... ..-8/1-16 R, 130.1

[56] I References Cited 5 'UNITED STATES PATENTS 3.492.316 1/1970 Adamsetal. v; ..8/l16R 3,506,390 4/1970 Naps 8/116 R 3,517,068 6/1970 Perrino 8/1 16 R 3,698,857 10/1972 Vigo et a1. 3/116 R 3,748,364 7/1973 Tesoro 8/116 R Primary ExaminerStephen J. Lechert, Jr.

[5 7 ABSTRACT Cellulose is Converted into sodium cellulosate by reac- I 10 Claims N0 Drawings I NON-AQUEOUS PROCESS FOR REACTING SULTONES WITH CELLULOSIC MATERIALS AND THE PRODUCT PRODUCED A non-exclusive, irrevocable, royalty-free license in the invention herein described, throughout the world for all purposes of the United States Government, with the power to grant sublicenses for such purposes, is hereby granted to the Government of the United State of America.

This invention relates to non-aqueous reactions of cellulose with hydrocarbon sultones. More specifically,

this invention relates to reaction of celluloses by known methods to prepare the sodium cellulosate which in turn is reacted with a selected sultone in the absence of water and without the assistance of catalysts. The resultant sultone-celluloses are useful as ion-exchange agents or where active acidic sites are required for further reactions of the cellulosic materials.

The main object of this invention is to provide a completely non-aqueous process for reacting cellulose with certain hydrocarbon sultones such as 1,3-propane sultone.

Another object of this invention is to provide a process by which the sultone solution is kept free of base so that it can be reused repeatedly.

a third objects of this invention is to provide a product which contains more sulfur than that which is obtained by an aqueous process wherein sodium hydroxide would be used.

In the prior art US. Pat. No. 3,506,390 discloses treatment of cotton with aqueous sodium hydroxide and further reacted in aqueous solution with propane sultone. The most sulfur added to the cotton by said treatment was 2.12%. This was obtained by the use of 25% concentration of sultone, a rather long reaction time (75 minutes), and an elevated temperature of 75C.

A water soluble adduct was reported by J. H. Helberger, et al., in Justus Liebigs Annalen Der Chemie, 565, pages 22 to (1949) Helberger reacted aqueous sodium hydroxide treated cellulose with butane sultone to form a water soluble adduct.

The specification of the present invention teaches the use of a non-aqueous technique for obtaining a higher sulfur add-on. The preferred solvent utilized in the process of this invention is tertiary butanol. However, there are other solvents which could be selected for obtaining an acceptable sultone-cellulose. The investigation leading to this invention yielded data which indicates that an amount of sulfur in excess of that added by use of water at C in 20 hours of reaction can be added in a single hour by the process of this invention. The present invention further teaches that a temperature as low as 35C correlated with reaction time of 1 hour will add as much sulfur to the cellulosic sultone product as the highest quantity addedby the aqueous process of US. Pat. No. 3,506,390 under the most extreme of conditions, that is, longer times, higher temperatures-and higher concentration of sultone.

According to the process of the present invention, dry preswollen cotton is converted to sodium cellulosate by reacting the swollen cotton with sodium methoxide. This, of course, is knownby those skilled in the art of textile processing. The sodium cellulosate thus produced is then washed with tertiary butanol. The sodium cellulosate at this point must be either stored under nitrogen in the solvent, which in this case happens to be tertiary butanol, or reacted immediately with a sultone in tertiary butanol. It should be emphasized that the use of tertiary butanol is preferred because the use of methanol, water, or other primary alcohol will reverse the formation of sodium cellulose, lowering the sodium content.

No sodium hydroxide nor sodium alkoxide is employed in the sultone solution of the present process; therefore the sultone solution can be used repeatedly and the reaction products contain more sulfur than the products of the prior art (an aqueous procedure). The products of the present invention are similar to those of the prior art and can be used for the same purposes except that the products of the invention have a much higher content (as high as about 10%) when compared to thoseof the prior art. Among these the use of the sulfonic acid group in subsequent reaction, as an acidic catalyst in crosslinking or polymerization reactions, and as an ion exchange medium can be considered significant.

Although sodium methoxide is preferred in the preparation of the alkali cellulosate, variations can be employed, such as the use of potassium methoxide or other alkali earth methoxide with any primary alcohol.

fibers, yarns, fabrics, or other materials which contain cotton, rayon, wood, linen, and the like.

Although the example reactions were carried out by immersion of the cellulosic material in cylinders containing the reagents, other means of contacting the textiles can be used-These include, but are not limited to,

padding, dipping, and spraying.-

' The sultone used for illustration is propane sultone,

but butane sultone could be used and other sultones as well can be similarly employed.

The time, temperature, and concentration of sultone in tertiary butanol can vary over'a wide range, depending on the desired result. The temperature can vary from about 26 to about 82C, i.e., over the tempera-- ture range in which tertiary butanol is liquid. The time can vary from minutes to hours, depending on the.

amount of reaction desired and the temperature used, although sufficient reaction can usually be accomplished in a period of from fifteen minutes to one hour.

The concentration of sultone in tertiary butanol can .vary from 1 to 25%, although'l0% was found to produce good results and there seemed no advantage to higher concentrations.

In a typical laboratory'use of this process a swatch of 3.12 oz. per square yard X 80 count) cotton printcloth which had been preswollen in dimethylformamide, dried and then reacted with sodium methoxide to produce the sodium cellulosate, was washed with tertiary butanol and then immersed in a 10% solution of propane sultone in tertiary butanol and kept there for a period of 1 hour at 50C. At the end of the reaction period the fabric sample was removed from the sultone solution, squeezed to remove excess solution and then washed in a water bath. The resultant product had a 2.85% sulfur. Although this sample of sodium cellulosate had 1.25 meq. of sodium per gram of material, sodium cellulosate has been prepared in this manner with up to 4.0 meq. of sodium per gram of material. This means that use of this process can result in products with sulfur contents of up to sulfur.

The examples belows are provided to illustrate the invention and are not to be construed as limiting the invention in any manner whatever.

EXAMPLE 1 Illustrating the advantage of usingtertiary butanol both as a washing'agent for the freshly formed sodium cellulosate and in the subsequent reaction A 12 in. square swatch for 80 X 80 count cotton printcloth weighing 3.12 oz'./yd was soaked overnight in dimethylformamide to preswell it and dried, then immersed in sodium alkoxide to produce sodium cellulosate. It was then washed three times with tertiary butanol to remove excess sodium ions. The sodium cellulosate fabric which contained 1.25 meq. Na per gram, while still wet with tertiary butanol, was placed in a cylinder containing 250 ml. of a 10% solution of propane sultone in tertiary butanol. The cylinder and contents were kept at 50C for a period of 1 hour. At the end of one hour reaction the fabric was removed from the propane sultone solution, excess solution squeezed out and ple added no sulfur. V

Conclusion: Tertiary butanol is necessary as a washing agent after the sodium cellulosate is formed and subsequent reaction in a solution of the sultone in this solvent adds sulfur whereas sulfur is notadded when methanol or water are used.

EXAMPLE 2 Illustrating that other 'nonaqueous solvents can be employed with propane sultone however unsatisfactory Example 1 was repeated but employing other solvents in the reaction of the sodium cellulosate with propane sultone. The results are here presented as percent sulfur content in the final product:

tertiary butanol 2.97% dimcthylt'ormamidc 1.86% acetone 2.15% water 0.9l%

EXAMPLE 3 Illustrating limit of reaction with respect to the addition of base in the'propane sultone solution Example I was repeated except that 2% sodium hydroxide was added to the solution of propane sultone in tertiary butanol. The sulfur analysis obtained for the product was 2.20%.

EXAMPLE 4 Illustrating reaction time limit Example 1 was repeated in a series of experiments to point out the relatively small changes obtained and the three experiments, the same propane sultone solution 5 limit observed as the reaction time was varied from 1 hour to 24 hours. The results are indicated in terms of sulfur content of the final product.

Reaction Time thrs.) l 3 6 16 24 Sulfur 2.83 2.90 2.92 2.96 2.95

EXAMPLE 5 Varying temperature Example 1 was repeated in a series of experiments to point out changes obtained and the limit observed as I temperature was varied from 25 to C. The results are indicated in terms of sulfur content of the final product.

Reaction Temp.(C) 25 p 35 50 6O 75 Sulfur 1.80 2.20 2.90 3.10 3.08

EXAMPLE 6 Reusing the propane sultone solution Example 1 was repeated except that, in a series of in tertiary butanol was employed, that is, the reactants for Sample 2 had already been used in reacting Sample 1, and were subsequently used inreacting Sample 3. The results are indicated in terms of sulfur content of the final product.

Sample 1 Sample 2 Sample 3 V Sulfur 2.91 2.94 2.88

Conclusion: The propane sultone, and possibly other sultones, in tertiary butanol may be used over and over again with substantially'the same-results as those of the initial reaction. it is to be expected that makeup solution will have to be added during normal repeated use but no makeup, however, was employed in the preparation of Sample 2 and 3.

EXAMPLE 7 Illustrating concentration limit Example 1 was repeated in a series of 3 experiments where the concentrations were varied from 5% to 20%.. The results are indicated in terms of sulfur concentration.

Sultonc Concentration Sulfur 1.61 2.78 2.84

We claim:

1. A process for producing sultone celluloses having ion-exchange properties with acid character, the process comprising reacting, in a non-aqueous solvent, washed alkaliearth cellulosate with sultone so as to yield a fibrous sultone cellulose.

2. The process of claim 1 wherein the alkali earth cellulosate is sodium cellulosate.

3. The process of claim 1 wherein the cellulosate is' obtained by reacting a cellulosic material with sodium methoxide in non-aqueous solvent.

4. The process of claim 3 wherein the cellulosic material is swollen with dimethylformamide before reacting with the sodium methoxide.

5. The process of claim 1 wherein the sultone is a hydrocarbon sultone at a concentration of from 5 to 25% in the non-aqueous solvent.

6. The process of claim 1 wherein the solvent is tertiary butanol.

7. The process of claim 5 wherein the hydrocarbon sultone is propane sultone.

8. The process of claim 5 wherein the hydrocarbon sultone is butane sultone.

9. The. product produced by the process of claim wherein the sulfur content is as high as about 10% with respect to the weight of the sultone-cellulose.

10. The product produced by the process of claim 1 wherein the sulfur content is about 10% with respect to the weight of the sultone-cellulose.

Claims

1. A PROCESS FOR PRODUCING SULTONE CELLULOSES HAVING IONEXCHANGE PROPERTIES WITH ACID CHARACTER, THE PROCESS COMPRISING REACTING, IN A NON-AQUEOUS SOLVENT, WASHED ALKALI EARTH CELLULOSE WITH SULTONE SO AS TO YIELD A FIBROUS SULTONE CELLULOSE.

3. The process of claim 1 wherein the cellulosate is obtained by reacting a cellulosic material with sodium methoxide in non-aqueous solvent.

6. The process of claim 1 wherein the solvent is tertiary butanol.

7. The process of claim 5 wherein the hydrocarbon sultone is propane sultone.

8. The process of claim 5 wherein the hydrocarbon sultone is butane sultone.

9. The product produced by the process of claim 1 wherein the sulfur content is as high as about 10% with respect to the weight of the sultone-cellulose.