John D. Guthrie

Determination of free gossypol in cottonseed materials

SummaryA method for the determination of free gossypol in cottonseed materials is described. The method consists of extraction of gossypol with a measured volume of 70% aqueous acetone on a shaker for one hour, filtration, and colorimetric analysis for gossypol in an aliquot of the filtrate by means of the reaction between gossypol andp-anisidine.The conditions for complete extraction of gossypol from various types of cottonseed materials have been investigated, the stability of gossypol in aqueous acetone has been demonstrated, and data are presented on recovery of gossypol added to cottonseed materials. The method has been compared with the method of Smith (2).

Ion-Exchange Characteristics of Chemically Modified Cotton Fabrics

A method is described for comparing microscopically the cross-sectional areas of the same cotton fiber in wet and dry conditions, for evaluation of swelling. Results indicate the change in cross-sectional area of raw cotton fibers to be between 21 % and 34% of the dry area regardless of variety of cotton or degree of maturity of the fiber. Immature samples show slightly less mean swelling than mature samples, but this is believed to be due to the presence of fibers with no secondary thickening at all which tend to shrink in cross-sectional area rather than swell. In the immature fibers deformation (defined as change in circularity) is slightly more than that of mature fibers. This, coupled with the fact that in a given weight of immature fibers there are approximately twice as many fibers as in a like weight of mature fibers, helps to explain the greater closing capacity of yarns made from immature cotton. Flax and a sample of viscose rayon show twice the swelling of cotton, Fortisan two-thirds as much, and nylon no crosssectional swelling at all.

Greater role for Atlantic inflows on sea-ice loss in the Eurasian Basin of the Arctic Ocean

Losing its character The eastern Eurasian Basin of the Arctic Ocean is on the far side of the North Pole from the Atlantic, but it is becoming more like its larger neighbor as the climate warms. Polyakov et al. show that this region is also evolving toward a state of weakened stratification with increased vertical mixing, release of oceanic heat, and less sea ice. These changes could have considerable impacts on other geophysical and biogeochemical aspects of the Arctic Ocean system and presage a fundamentally new Arctic climate state. Science, this issue p. 285 The eastern Arctic Ocean is becoming more like the Atlantic as climate changes. Arctic sea-ice loss is a leading indicator of climate change and can be attributed, in large part, to atmospheric forcing. Here, we show that recent ice reductions, weakening of the halocline, and shoaling of the intermediate-depth Atlantic Water layer in the eastern Eurasian Basin have increased winter ventilation in the ocean interior, making this region structurally similar to that of the western Eurasian Basin. The associated enhanced release of oceanic heat has reduced winter sea-ice formation at a rate now comparable to losses from atmospheric thermodynamic forcing, thus explaining the recent reduction in sea-ice cover in the eastern Eurasian Basin. This encroaching “atlantification” of the Eurasian Basin represents an essential step toward a new Arctic climate state, with a substantially greater role for Atlantic inflows.

Flame Retardants for Cotton Using APO and APS-THPC Resins

A new group of polymers made by reacting tris(1-aziridinyl)phosphine oxide, referred to as APO, or tris(1-aziridinyl)phosphine sulfide, referred to as APS, with tetrakis- (hydroxymethyl)phosphonium chloride, referred to as THPC, are good permanent-type flame retardants for cotton. All three of the compounds are water-soluble crystalline materials. The application of APO- or APS-THPC resins to textiles consists of padding fabric in an aqueous solution of the compounds, drying the fabric, curing it at about 140° C. for about 5 min. to polymerize the compounds, and then rinsing the fabric to remove any unpolymerized material. About 8% of the resins in 8-oz. cotton twill or sateen is adequate to make the fabric pass the vertical flame test before or after 15 launderings with synthetic detergents, followed by an acid fluoride sour after each laundering. The flame resistance is also very durable to boiling alkaline soap solutions. The properties of fabric treated with these new polymers are, in general, excellent. The hand and strength of the fabric is only slightly different from that of untreated fabric. The flame-resistant fabrics are resistant to rot and mildew.

Chemical and Physical Properties of Aminized Cotton

curing with 2-aminoethylsulfuric acid in the presence of sodium hydroxide. Fabric may be conveniently aminized in a practical manner using standard cotton chemical finishing equipment. Sliver aminized by the process described may be opened, recarded, and converted into yarn. Experiments dealing with the effect of various processing conditions on the aminization of sliver are reported. It is shown that 30%

Imparting Crease Resistance and Crease Retention to Cotton With APO

Cotton fabric (80 × 80) was made crease resistant by processing with APO, tris(1-aziridinyl)phosphine oxide. Application was made by wetting the fabric with an aqueous solution of APO containing catalytic quantities of zinc fluoborate, squeezing out the excess with squeeze rolls, drying for 4 min. at 80-90° C., and curing for 4 min. at 140° C., followed by a good wash. An aftertreatment with a 1% Primenit VS2 solu tion increased the crease recovery angle. Monsanto crease angles of from 250° to more than 300° (warp + fill) have been obtained, depending on the resin add-on. The crease recovery is not changed much by home laundering. A loss of 30% in the Elmen dorf tearing strength was observed with samples with over 300° crease recovery angles. Creases durable to washing were obtained by drying the fabric with a hand iron followed by an oven cure. The resin could not be stripped from the fabric by methods that are effective with other resins. In addition to imparting crease resistance, this resin also imparts some degree of flame resistance.

Aminization of Cotton

A FEW YEARS AGO it was found that amino groups could be attached to the cellulose of cotton by reacting it with 2-aminoethylsulfuric acid in the presence of sodium hydroxide [2]. A degree of aminization represented by 0.3 % to 0.4% nitrogen may be readily obtained by this method. Although this level of aminization is adequate for demonstrating the unique dyeing characteristics and for some experimental work, a number of potential applications of aminized cotton require a higher degree of aminization.

Insolubility in Cuprammonium Hydroxide as a Means of Detecting Crosslinking in Chemically Modified Cotton

Native cellulose dissolves in cuprammonium hydroxide solution, but, when it is crosslinked, it becomes a space polymer and is insoluble in this reagent. A method of detecting alkali-stable crosslinks in cotton is presented—the sample to be tested is shaken with cuprammonium hy droxide solution for 17 hr. If it dissolves completely, cellulose chains are not crosslinked, but, if it is partially insoluble, crosslinking is indicated. Partially insoluble cellulosic material appears in the cuprammonium hydroxide as granules that are easily detected visually. Cellulose was reacted with compounds which contained one or more groups that are reactive toward cellulose. In all cases the cellulosic derivatives made from cellulose and compounds that could crosslink it were partially insoluble in cuprammonium hydroxide. The compounds that were not capable of crosslinking cellulose produced derivatives soluble in cuprammonium hydroxide. Cotton was made insoluble in cuprammonium hydroxide by reacting it with formaldehyde, glyoxal, chloroethylsulfuric acid, α,γ-glycerol dichlorohydrin, a mixture of α,β- and α,γ-glycerol dichlorohydrin, tetrakis (hydroxymethyl) phosphonium chloride, compounds containing two or more N-methylol groups, 1,4-disulfato-2-butyne, and potassium (disulfatoethyl) amine. Aminized cotton, which is soluble in cuprammonium hydroxide, was made insoluble by cross linking it with either formaldehyde or tetrakis (hydroxymethyl) phosphonium chloride.

The tannin and related pigments in the red skins (Testa) of peanut kernels

SummaryThe red skins of peanut kernels contain a catecholtype tannin. The purified tannin represented about 7% of the weight of the skins. Much smaller quantities of phlobaphene and so-called “leuco-anthocyanic chromogen” were isolated from the skins. Some evidence of the presence of traces of a flavonic-type pigment was obtained.Spectrophotometric investigations of the isolated tannin, phlobaphene, and “leuco-anthocyanic chromogen” indicated a close relationship of the three pigments.The tannin gave a water-soluble red pigment when refluxed with alcoholic hydrochloric acid. This pigment exhibited certain properties which are indicative of an oxonium-type structure.The elementary analyses and certain properties of the isolated tannin and related pigments were considerably different from those reported by previous investigators. The amorphous nature of these substances makes chemical investigation difficult.

Bromine-Containing Phosphonitrilates as Flame Retardants for Cotton

Bromine-containing derivatives of phosphonitrilic chloride were investigated as pos sible durable flame retardants for cotton fabrics. These, including brominated allyl phosphonitrilate, 2, 3-dibromopropyl phosphonitrilate, and the bromoform adduct polymer of allyl phosphonitrilate, were applied to cotton fabrics as polymeric products from or ganic solvent or from aqueous emulsions. Evaluation tests on tear strength and the durability of the flame resistance to laundering were made.