Cupriethylene Diamine Research Articles

A Pure-Culture Inoculum Method for Evaluation of Forage Cellulose Digestibility

A microbiological method based on the use of B. succinogenes S85 as inoculum for evaluation of forage cellulose digestibility was developed. Factors such as age and concentration of inoculum and length of fermentation period were studied to determine the effect of these variables on cellulose digestion so that a standard method with high precision was obtained. Cellulose digestion values obtained by this technique were highly correlated with cellulose soluble in cupriethylene diamine, in vitro mixed-culture rumen cellulose digestion and in vivo dry matter and organic matter digestion. Correlations with Nutritive Value Index were highly significant for grasses but not for legumes. The significance of this microbiological method is primarily in the reduction of within and between-trial variability for the laboratory evaluation of forages.

Estimation of the Digestibility and Nutritive Value of Forages by Cellulose and Dry Matter Solubility Methods3

An improved procedure has been developed to determine the solubility of forage cellulose in cupriethylene diamine (CED). Values obtained with this method were highly correlated with the D.M. digestibility, energy digestibility and NVI of grasses and mixed forages, but not legumes. An additional chemical analysis, dry matter solubility (DMS) of the forage in 1.0 N H2SO4, was found to be well correlated with the relative intake as well as D.M. digestibility, energy digestibility and NVI for grasses, mixed forage and legumes. When the data from all types of forages (39 samples) were combined and correlated against the CED and DMS methods as well as the product ( CED × DMS) of the two methods, the best correlations obtained were as follows: D.M. digestibility (CED × DMS), 0.87; Energy digestibility (CED × DMS), 0.88; NVI (DMS), 0.83; and Relative intake (DMS), 0.78.

The action of epichlorohydrin in the presence of alkalies and various salts on the crease recovery of cotton

AbstractAs a phase of an investigation of the cellulose–epoxide reactions, experiments have been performed in which epichlorohydrin reacted with cotton cellulose in the presence of sodium hydroxide and various salts. Acidic and basic salts, as well as those which are relatively neutral in aqueous solutions, were used in pretreatments for the cellulose–epichlorohydrin reaction. No reaction with cellulose occurred in the presence of acid salts and only very slow addition of epichlorohydrin to cellulose in the presence of neutral salts; the greatest reaction was produced with basic salts. Particular emphasis was given to use of certain salts known to cause epichlorohydrin to undergo a type of cyclization reaction. Previously published methods, used for imparting both wet and dry crease resistance to cotton fabrics by means of diepoxides in the presence of NaOH, have resulted in wet crease resistance only when applied to the application of epichlorohydrin. Among the basic salts investigated, 20% solutions of sodium azide used in pretreatments were found to produce low weight gains of epichlorohydrin and a fair degree of dry and wet crease resistance in cotton after a slow reaction at 25°C. or a faster reaction at 80°C. The greatest improvement in dry crease resistance with epichlorohydrin was obtained by pretreatments with concentrated solutions of sodium orthosilicate, sodium metasilicate, or trisodium phosphate at 80°C. The effects of amount of water at time of reaction as well as speeds of reaction with the various pretreatments have been considered. Optical and electron microscopical examinations of fibers and ultrathin cross sections of fibers, respectively, after immersion in cupriethylene diamine (cuene) have indicated that the cellulose–epichlorohydrin reaction at 80°C. after pretreatment with concentrated solutions of silicates or phosphates differed from that after pretreatment with sodium hydroxide at all concentrations. Even when the pretreatments were with dilute sodium hydroxide, the epichlorohydrin‐reacted fibers were more swollen in cuene than were those treated fibers which had been pretreated with the concentrated silicates or trisodium phosphate solutions. Decrease in amount of swelling and dissolution in cuene was found to correlate with increase in dry crease resistance of the fabrics. While all these treated fabrics possessed high wet crease resistance, only those pretreated with the aforementioned concentrated salt solutions possessed good dry crease resistance. Effects of base‐catalyzed addition of certain monoepoxides to cotton on the resultant crease resistance properties of the fabrics have been reported and compared with properties imparted by epichlorohydrin. Attempts have been made to explain why the number of cellulose crosslinks formed per unit of time by epichlorohydrin is greater, when silicates or phosphates at high concentrations are present with hydroxyl ions, than when hydroxyl ions only are present.

Viscometric determination of molecular weight of cellulose pulps in zinc ethylenediamine solution

A convenient method of preparing zinc ethylenediamine complex (ZED) solution for use as solvent for cellulose pulp is described, and the advantages in using this solvent (0.25M zinc in 41% ethylenediamine in water) over cupriethylenediamine (CED) or cuprammonium solutions for viscometric determination of molecular weight of cellulose are indicated. Intrinsic viscosities of eight rayon-grade pulp solutions have been determined at four temperatures: 15, 20, 25, and 30°C. The constants K = 5.85 × 10−5 and a = 0.936 of the Mark-Houwink equation [η] = KM, required for evaluating the molecular weight of cellulose pulps in ZED solution, have been determined by using the molecular weight values obtained from CED solutions.

Effect of Particle Size upon the in Vitro Cellulose Digestibility of Forages by Rumen Bacteria1,2,3

Summary Rates of in vitro cellulose digestion were determined for mature timothy (seed ripe) which had been ball-milled 0, 6, 24, and 72 hr. The total amount of cellulose digested increased with the time of ball-milling up to 72 hr. Based on this observation four stages of timothy, three of alfalfa, and two each of brome and orchard grass, along with 72-hr. ball-milled samples of these same forages, were used as substrates for in vitro rumen fermentations. In all cases, ball-milling increased the amount of cellulose digested, and this increase became larger with advancing maturity and lignification of the forage. In further work, mature timothy was digested 48 hr. in vitro and the residue isolated. Less than 5% of the cellulose remaining in this residue was digested in a second 48-hr. fermentation; however, when a portion of this residue was ball-milled, 67% of the cellulose could be digested. Additional experiments which determined the amount of forage cellulose soluble in cupriethylene diamine, indicated that the amount of cellulose which can be dissolved decreases with forage maturity and increased deposition of lignin. The amount of cellulose dissolved was markedly increased after ball-milling, and again this increase became larger with advancing maturity of the forage. The experimental evidence presented in this paper substantiates the theory that the lignin in forages acts as a physical barrier between the cellulose and cellulolytic rumen bacteria.

New types of membranes for osmotic pressure measurements

AbstractSemipermeable membranes used for osmotic pressure measurements are usually made from collodion or from regenerated cellulose or from other cellulosic materials. Such membranes are readily attacked by corrosive solvents, they are easily oxidized, and they can be used for only a few hours at high temperatures. To overcome these difficulties new noncellulosic membranes have been developed. The preparation of a polyvinyl butyral membrane and of a Kel‐F (polychlorotrifluoroethylene)membrane is described. The data for typical osmotic pressure measurements using the new membranes are presented. The Kel‐F membrane can be used for measurements in all common organic solvents as well as for solutions of cellulose in solvents such as cupriethylene diamine and cuprammonium hydroxide. It is also suitable for high‐temperature osmotic pressure measurements.

Behavior of a synthetic polypeptide analogous to protein denaturation.

SOME observations made recently in this laboratory suggest a considerable resemblance, in certain respects, between poly DL-alanine and the soluble form of silk obtained from solution in cupriethylene diamine or lithium bromide solution1,2.

Fractionation of Cellulose Acetate and Distribution of Non-Cellulosic Components between the Fractions

Abstract 1. Three cellulose acetates from cotton linters, Kayaceta and a domestic pulp were fractionally precipitated from acetone solution with ethanol, and viscosity measurements in acetone solution and pentosan determinations by paper chromatography of the individual fractions were made. 2. Another acetate from Rayaceta was again fractionated into five fractions and viscosities in acetone and cupriethylene diamine solution and pentosan contents of the individual fractions were determined. 3. The results showed a close relationship between the initial acetone-insoluble fractions or in acetone haze-producing fractions and their pentosan content. These fractions include abnormal materials which show low viscosity (probably low D. P.) in cupriethylene diamine solution as well as in acetone. They are in-cluded much in the acetates from wood pulps. 4. It could not be decided whether these acetone-insoluble fractions were due to association by salt bridge effect of calcium ions between carboxyl or sulfuric half-ester groups, or due to the remaining structure of wood tissues. 5. The chain-length distributions of the cellulose acetates from wood pulp seem to be more heterogeneous than those from cotton linters.

ON CUPRIETHYLENE DIAMINE AS A SOLVENT FOR THE PRECISE DETERMINATION OF PULP VISCOSITY.

Cuprammonium hydroxide has long been used as a dispersing agent for the determination of pulp viscosity. Cupriethylene diamine dispersions are, however, much less sensitive to low oxygen concentration than are cuprammonium hydroxide dispersions. This solution is an excellent dispersion medium for cellulose, it is nonvolatile, , it has excellent keeping qualities, provided it is kept stored under an atmosphere of nitrogen, and it is easily prepared in quantity.A cupriethylene diamine trial method for rapid viscosity determination was presented and it was recognized that the relative viscosity of various pulp can be determined to an accuracy of approximately±5% by this method.

Cupriethylene Diamine as Solvent for Precise Determination of Cellulose Viscosity

Cupriethylene Diamine as Solvent for Precise Determination of Cellulose Viscosity