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The age related variation in magnesium and calcium content and mechanical properties of turkey tendon from ages 9-14 weeks has been studied. The results show that magnesium content decreases with age during this period and calcium content remains essentially constant. This is in accord with a previously proposed mechanism of calcification, namely, that the local concentration of magnesium and calcium may be an important factor relating to the initiation of calcification in a given tissue. The tensile strength of the turkey tendon has been found to decrease with age during the precalcified period of 9-12 weeks, after which there is an increase in tensile strength coincident with the onset of calcification. The ultimate elongation decrease of approximately 4% between 9 and 13 weeks is attributed to the difference in extensibility of the 'wavy' collagen fibers observed in uncalcified turkey tendon vis a vis the straight fiber bundles in turkey tendon specimens observed at the onset of calcification. [ABSTRACT FROM AUTHOR]

This paper describes laboratory experiments designed to show what improvements can be achieved in the properties, particularly the modulus, of ICI nylon 6.6 tyre cords. The experiments fall into four groups: (i) hot-stretching tyre cords under conditions more severe than those conventionally used, up to the maximum temperatures and tensions possible; (ii) as in (i), but using cords made from hot-stretched yams; (iii) as in (i), but using twist levels lower than the conventional ones; (iv) as in (iii), but using cords made from hot-stretched yams. [ABSTRACT FROM AUTHOR]

Resin stripping of treated cotton fabric (removal of resin by acid hydrolysis) was investigated by measurements of textile properties, by viscometry, and by gel-permeation chromatography (GPC). Breaking strengths and elongations- at-break, which were reduced by treatment with dimethylolethyleneurea (DMEU), were partially restored by resin stripping. The acid-catalyzed treatment of the fabric with the substituted urea substantially reduced the degree of polymerization (DP) of the cotton cellulose; resin stripping further reduced the DP. The restoration of tensile properties which occurred even though DP had been reduced was due to removal of crosslinks which cause crosslink embrittlement. [ABSTRACT FROM PUBLISHER]

Lactamide and N-methylollactamide have been used to modify conventional ethyleneurea-formaldehyde, prolylene urea-formaldehyde, dihydroxyethyleneurea-formaldehyde, and other resins. The effect of these modified resins is great est when they are used on 100% cotton fabrics. In general, while developing a desirable wash and wear rating, physical properties such as abrasion resitance, tensile strength and elongation are significantly increased. Lactamide also seems to have a definite favorable effect on the hand and on the bulkiness of the fabric. Lactamide modified resins have also been applied to cotton-polyester blends where they improve the resistance of the fabric to frosting as well as improving other properties. [ABSTRACT FROM PUBLISHER]

Cotton twill fabric was treated by a pad-dry-cure process with combinations of DMDHEU and several potycarboxytic acids. Fabrics were prepared with several ratios of catalytic rarhoxylic acid groups to DHEU residues in the modified cellulose. The wrinkle-recovery angles, durable-press appearance ratings, and strength retentions of these fabrics were equivalent to or slightly better than those imparted by the conventional DMDHEU-MgCl2 treatment. The fabrics were analyzed for nitrogen, formaldehyde, ester linkages, and free carboxytic acid groups. The ratios of formaldehyde residues to DHEU residues in the cured experimental fabrics decrease with increasing wrinkle-recovery angles of the fabric. These fabrics showed very good recurahility when prepared with selected polycartroxylic acids, e.g., citric, cyctopentanetetra cartroxylic, and tetrahydrofurantetracarboxylic acids. The rerurahility was lost by converting the free carboxyl groups in the fabric to salt forms, but was restored when the free carboxyl groups were regenerated. [ABSTRACT FROM PUBLISHER]

Details of a preirradiation grafting technique to render cellulosic fibers highly elastic have heen examined. Special emphasis has been given to the grafting of ethylacrylate to continuous filament rayon from an aqueous emulsion. In addition comparative studies using selected chemically initiated systems have been carried out. Preirradiation grafting rates were found to increase substantially with temperature, reducing the grafting times necessary to achieve highly elastic rayon to the order of minutes at 50°C compared to 20 hr at ambient temperatures. The onset of high "rubber like" elasticity occurs around 1000%, accompanied by a large drop in tenacity. By adding a small quantity of a bi functional monomer to the grafting solution, this strength loss can be reduced without any loss in elongation. Elastomeric properties have been attained even at grafting levels below 100% by subjecting the grafted fihers to a treatment capable of decrystallizing the cellulose. The morphology and structural modifications observed by electron microscopy and x-ray diffraction are discussed for rayon fibers grafted to various levels by both preirradiation and chemical initiation, with and without sulsequent postdecrystallization. These studies indicate that in order to achieve elastomeric properties, grafting must take place throughout the fiber, expanding the fiber and disrupting its crystalline regions. [ABSTRACT FROM PUBLISHER]

Losses in tensile and tearing strengths and other physical properties of cotton fabric given durable-press finishes have been attributed to factors arising mainly from the crosslinking of the cellulose molecule. This conclusion was deduced from the results of textile testing of the treated fabrics. In order to define the sources of these strength losses, a study was made of cotton fabric treated with dimethylolethylene urea and a zinc nitrate catalyst in a commercial manner, but with varying times of cure. Heretofore unobtainable molecular parameters of durahle-press cotton fabric were estab lished from solubilized samples. Correlations made between physical properties of the fabric and the fine-structural features of the fiber, both of which were measured, estahlished the fractions of losses arising from molecular degradation and from crosslink embrittlement as a function of the extent of cure. In the shorter cure times, the predominant strength loss came from crosslink embritttement, but this proportion dropped rapidty and molecular degradation became the major source. Changes in degree of polymerization suggest that the catalyzed crosslinking reaction produces a limited chain extension of the cellulose molecule which becomes evident after removal of the crosslinks. [ABSTRACT FROM PUBLISHER]

The paper deals with studies elucidating the effects of hank of the ingoing material and of doubling at the ringframe upon yarn quality and spinning performance under different spinning conditions obtained by varying the spindle speed and count spun. The results show that with coarse and medium mixings, the hank of the roving fed could be varied over a wide range without affecting yarn properties. The use of finer hank, however, led to a reduction in end-breakage rate in such mixings. With fine mixings, finer input hank and low ringframe drafts led to poorer yam quality and comparable or poorer spinning performance.Doubling at the ringframe improved the strength and regularity of yarns significantly in the case of coarse and medium mixings but only marginally in the case of fine mixings. The improved yarn quality thus obtained did nbt lead to better ringframe performance and the relative merits of single and double feeds in this regard were dependent upon mixing characteristics and spinning conditions. With coarse mixing, double feed invariably led to inferior spinning performance and the effect became highly pronounced when overspinning or at higher spindle speeds. With fine mixings, the two feeds were comparable at lower counts and spindle speeds but the deterioration in performance with increase of count or spindle speed was more rapid with double feed. In double feed spinning, end breakage rate was found to be lower on those spindles where the rovings were kept together by means of a cross-over of the strands in the break draft zone. The application of a condenser to keep the strands together was helpful in overcoming the deterioration in spinning per formance in double feed. The Minimum twist spinning test showed a better correspondence with end breakage rate under adverse conditions of spinning than under normal conditions. [ABSTRACT FROM PUBLISHER]

Graft copolymeriration of methyl methacrylate was performed onto wool reduced by various chemicals using ferrous ammonium sulfate and hydrogen peroxide redox system at 45°C temperature. Reduced wools show higher percentage of polymer deposition as compared to natural because the thiol groups act as graft centers. Mechanical properties of MMA-reduced wool graft copolymers were studied. Results indicate that, with approximately 50% graft copolymeriza tion, the decrease in elongation is considerably high and the tensile strength is decreased slightly. In case of modulus, an initial increase with polymer deposition followed by a decrease. Density and moisture regain were also determined and the results were discussed in relation to mechanical properties of graft copolymers. [ABSTRACT FROM PUBLISHER]

Cotton print cloth was reacted with 1, 3-bis (hydroxymethyl)-2-imidazolidinone (dimethylol ethylene urea) and with several modifications of this compound which had varying hydrogen-bonding capabilities but were still capable of cross-linking the cellulose. Reactions were carried out in two solvent systems, water and dimethylformamide, using Zn (NO3)2.6H2O as the catalyst. Add-ons of the cross-linking agents and changes in the physical properties of the treated fabrics were determined. Infrared spectra of the treated fabrics were obtained and infrared bands characteristic of the hydrogen-bonded structure of cellulose were studied and used to qualitatively suggest changes in that structure. It appears that hydrogen bonding of the cellulose with substituents on the resin is not significant in producing changes in the physical properties, including resiliency, of cross-linked cotton. The reactivity of these resins and the type of bond formed with the cellulose system (intra- or inter-molecular) seem to be the major causes of differences in physical properties of the treated fabrics. [ABSTRACT FROM PUBLISHER]

A study was made of the chemical reactivity of wool in dimethyl sulfoxide (DMSO) as well as the effect of DMSO and related aprotic solvents on the physical properties of wool. Some functional groups in wool, especially amino groups of lysine and imidazole groups of histidine, are readily modified in DMSO in the presence of triethylamine by activated vinyl compounds (e.g., acrylonitrile and (di)vinyl sulfone). Treatment with vinyl sulfone increases the resistance of wool to oxidation by peracetic acid, suggesting that new cross links are present. Also studied were (a) the relative reactivities in aqueous, aqueous-DMSO, and DMSO media; (b) the supercontraction of wool and densification of felts by DMSO; (c) the effect of heating wool in DMSO on amino acid composition; and (d) stress relaxation of hair, including sulfhydryl- disulfide interchange. Our studies suggest that DMSO is a useful medium in which to modify wool with various reagents. In some applications, DMSO has advantages over water. [ABSTRACT FROM PUBLISHER]

On treatment with a variety of swelling agents, polyhexamethylene terephthalamide (nylon 6-T) fibers undergo char acteristic changes in tensile properties, x-ray pattern, and dyeability. Microscopically visible voids are permanentlv removed and the uptake of acid and disperse dyestuffs is increased in that portion of the fiber penetrated by the swotting agent. The molecular rearrangement which occurs during this "relaxation" consists of disorientation and probably in volves a change in the relative positioning of successive hydrogen-bonded sheets. It is suggested that the change in dyeing behavior on relaxation consists in general of an increase in extent of the so-called "overdyeing" resulting from the genera tion of additional "vacancies." [ABSTRACT FROM PUBLISHER]

Changes in internal fiber structure of cotton during swelling and tensioning were determined from the effects of these changes on physical properties imparted by cross-linking with dimethylolethyleneurea (DMEU). Cotton yarns were swollen with various agents and subjected to tension during swelling and subsequent washing. Dimethyl sulfoxide (DMSO), aqueous benzyltrimethylammonium hydroxide (BTOH), and solutions of KI and KCNS in NaOH were used as swelling agents. The effect on structure caused by repeated cycling between slack and original length during the base-swollen stage was judged from the effect of subsequent low-level cross-linking on physical properties. Resin pickup and distribution in the yarns were controlled by high-speed centrifugation.The type and concentration of swelling agent are related to the form and degree of tension needed during the swelling steps to produce optimum properties after cross-linking. Improvement of physical properties after cross-linking was found to correlate with increased crystallite orientation over a part of the range studied. The relationship between degree of conversion of native cotton to Cellulose II and energy-to-rupture values is discussed. The characteristic features of low- level cross-linking previously observed in the fiber fragmentation patterns of yarns treated with DMEU, centrifuged to a low wet pickup, and cured, were also seen in the samples repeatedly swollen and restretched prior to DMEU treatment, centrifuging, and curing. [ABSTRACT FROM PUBLISHER]

This study was directed primarily at the physical property changes in fibers, yarns and fabrics as smooth drying proper ties are developed in cotton by pad-dry-cure, mild-cure, poly-set and wet-fix processes. Bound nitrogen differed appre ciably in the final products, the maximum nitrogen being required in the wet-fix and the minimum in the poly-set cottons. Compared to pad-dry-cure cottons, tensile properties change more rapidly with bound nitrogen during the initial reaction periods for poly-set and wet-fix cottons and in the final reaction period for mild-cure cottons. Tenacity of single fibers had larger differences at the maximum levels of reaction than did those of the yarns or fabrics. In dual step processes, poly-set and wet-fix, strength decreased with each step. Recovery from tensile strain in single fibers was inversely related to retained strength, the wet-fix cottons had the smallest strength loss and the smallest increase in recovery. Incon sistencies between crease recovery for fabrics and strain recovery for fibers indicate that fiber properties other than strain recovery are affecting crease recovery and smooth-drying of fabrics. [ABSTRACT FROM PUBLISHER]

Sodium cellulosates containing from 0.5-1.9 mequivs of Na+ per gram of fabric were prepared by reacting cotton in methanolic solutions of sodium methoxide. The sodium cellulosates were reacted with β-chloroethyldiethylamine in t-butanol to form diethylaminoethyl (DEAE) cottons of greater than 1.0% nitrogen. These DEAE -cottons, easily pre pared at room temperature, were readily converted to the quaternary-base cellulose anion exchangers. Quaternary-base anion exchangers of lower capacity were prepared by reacting sodium cellulosates with glycidyltrimethylammonium chloride. Anion exchangers prepared in nonaqueous media did not differ in fabric properties from anion exchangers of similar capacities prepared in aqueous media. Ability of amino groups to catalyze cellulose-epoxide reactions was not significantly different in DEAE-cottons prepared in nonaqueous and in aqueous media. [ABSTRACT FROM PUBLISHER]

The influences of growth environment on gross and fine structures, mechanical properties, and responses to chemical treatments were determined from cotton fibers of Rex and Texas Marker-1 varieties grown under ranges of controlled environment. Cell walls of fibers composed of cellulose deposited at constant and varying temperatures were found to differ in many of their properties. The cell wall thickens more slowly at lower than at higher temperatures and the walls are thinner even though the wall development periods are longer. Properties of fibers indicate that cellulose from the low-temperature environment is less compact and more responsive to chemical reagents than from the high temperatures. The fibers from low temperatures are weaker and more extensible. Relationships between cell wall thickness, fine structure, mechanical properties and chemical reactivities are illustrated. [ABSTRACT FROM PUBLISHER]

A cotton fabric was artificially soiled and laundered with two different types of detergents at two different wash tem peratures. Samples laundered at 140°F were rated by subjective evaluations to be whiter, softer, and smoother than fabric laundered in unheated water. The type of detergent did not affect the softness or smoothness of the fabric. Sam ples laundered in regular detergent were judged to be whiter than those laundered in cold-water detergent. Little dif ference in breaking strength, elongation, and dimensional change of the fabric due to laundering variables was noted. Data are given on the cost of heating water and detergent. Samples were laundered at six locations and differences in water quality are reported. [ABSTRACT FROM PUBLISHER]

Low-twist yarns made from Deltapine cotton were ethanol-extracted and chemically treated while slack. Fibers were taken from yarns treated with formaldehyde, by various procedures producing differences in swelling of the fiber structure when cross-linked; dimethylol ethyleneurea; N-methylol-N'-methylethyleneurea; and oleoyl chloride.Single fibers progressively lose strength and elongation with increasing cross links when tested at 70°F, 65% RH and when wet. Cross links introduced in the swollen fiber structure usually cause less strength loss than those introduced in the nonswollen structure. Tensile strain recovery for single fibers increases with increasing cross links. The initial are more effective than the subsequent cross links. Increased energy recovery is related to increased strain recovery. Single fibers cross-linked in slack yarns show increases in recovery with decreases in stiffness. The retention of strength and the improved ability to recover are limited to some modifications, especially under the wet conditions. Changes in mechanical properties of cottons by smooth-drying treatments are due, in part, to changes in mechanical properties of the individual fibers. [ABSTRACT FROM PUBLISHER]

Cotton cellulose fabrics containing quaternary ammonium hydroxide groups at three levels of substitution were prepared directly from reaction of print cloth with 3-chloro- 2-hydroxypropyltrimethylammonium chloride or with glycidyltrimethylammonium chlo ride. The reactions involved sodium hydroxide solutions of mecerizing strength. The chemically-modified fabrics were characterized for primary physical performance proper ties and for self-catalyzed reactions with divinyl sulfone and bis-(2-hydroxyethyl) sul fone. The results extend information already reported for unmercerized cotton cellulose containing quaternary ammonium hydroxide groups generated by quaternization of 2-diethylaminoethyl substituents. The nature of the quaternary ammonium substituent and the mercerized or unmercerized state of the cotton fibers are shown to have a bearing on the efficiency of this self-catalyzed reaction and on the wrinkle recovery angles and other properties developed in the products. [ABSTRACT FROM PUBLISHER]

Anisotropic dimensional changes in uniaxially oriented acrylonitrile copolymer film during coagulation were investigated isothermally by varying the NaSCN concentration. Anisotropic dimensional change occurs when the swollen acrylonitrile films are im mersed in a strong nonsolvent (e.g., 35% NaSCN) or the degree of orientation prior to cross-linking at an adequate level, and swelling is high enough. The former phe nomenon is due to skin (semipermeable membrane) formation and nonuniform coagula tion; the latter phenomenon is due to spontaneous elongation, and the wide-angle x-ray diffraction measurements show that it occurs with crystal-liquid transformation in accordance with the previously reported theory that reversible contractile processes are related to these transformations. [ABSTRACT FROM PUBLISHER]

Cotton fabrics were treated with DMDHEU in a conventional pad-dry-cure process, or a mixture of N-methylol acrylamide (NMA), acrylamide (AM), and tetraki(hydroxy methyl)phosphonium chloride (THPC) in a system where in situ polymerization is en couraged. Yarns drawn from treated fabrics were tensile-tested at two rates of loading. The dependence of coefficient of variation (CV) in breaking-strength distribution on chemical cross-linking, polymer deposition, and rate of loading is discussed. It is con cluded that coefficient of variation in breaking-strength distribution can be a useful parameter in interpreting structural changes resulting from chemical treatment of fabrics. The information obtained is not apparent if only average breaking strength is considered. [ABSTRACT FROM PUBLISHER]

Rats of three different ages (7, 13, and 22 days) were given a single injection of acetate-1-14C, then sacrificed at intervals (4 hr, 2 days, 10 days, and 30 days). The fatty acids of brain gangliosides, glycerophosphatides, cerebrosides, and sulfatides were isolated and counted. Some were decarboxylated and the resultant carbon dioxide was counted.The data indicate that the palmitate of gangliosides and glycerophosphatides is made de novo from acetate, but that the stearate of these lipids is made by elongation of palmitate. The palmitate used for elongation is not the freshly synthesized acid but rather the acid recently liberated by breakdown of the complex lipids. Lignocerate also appears to be made by elongation, but it is possible that the stearate of cerebroside is made de novo. No qualitative difference was seen in the turnover curves or modes of biosynthesis in the three rat groups. The turnover rates for ganglioside fatty acids were similar to those for the phosphoglycerides. Turnover data for sphingosine in cerebrosides and sulfatides are presented.

Subcellular fractions of aorta of squirrel monkey (Saimiri sciureus) were examined for their ability to synthesize and elongate fatty acids. High-speed supernate (HSS) incorporated substantial quantities of malonyl CoA into fatty acids while acetyl CoA was much less effectively utilized. Acetyl-CoA carboxylase activity exceeded the amount of acetyl CoA incorporated into fatty acids and thus does not account for the low incorporation of this substrate. Microsomes used malonyl CoA and acetyl CoA equally well; mitochondria incorporated either acetyl CoA or acetate. The amounts of substrate incorporated into fatty acids (mμmoles/mg of protein per hr) were 2.3 for HSS, 1.2 for microsomes, and 0.9 for mitochondria.The synthesized fatty acids were separated by gas-liquid chromatography, radioassayed, extracted from the scintillation fluid, and decarboxylated. HSS completely synthesized palmitic and stearic acids from malonyl CoA. Microsomes and mitochondria utilized acetyl CoA to elongate endogenous fatty acids and gave mainly palmitic, stearic, and C18 and C20 monoenoic acids, with lesser amounts of other saturated and unsaturated fatty acids. A significant quantity of malonyl CoA was utilized by microsomes to yield a fatty acid tentatively identified as docosapentaenoic. Radioactive fatty acids are incorporated into various lipid classes by the particulate preparations.These studies demonstrate that aortic tissue in a nonhuman primate is able to carry out several processes of fatty acid metabolism and that the aortic synthesis and elongation of fatty acids may play an important role in providing fatty acids for incorporation into aortic lipids.