Decomposition Of Cotton Research Articles

Sowing seeds of prosperity: Uncovering the calculated growth, instability and decomposition of cotton in India

The present study examines the growth, instability and decomposition of cotton in India. The compound growthrate analysis revealed that the cotton cultivation area in India experienced a compound growth rate of 0.68 per cent, cottonproduction showed a compound growth rate of 3.31 per cent and cotton yield exhibited a compound growth rate of 2.6per cent from 1951 to 2020. The instability analysis using the Cuddy-Della Valle index indicates that cotton production hada coefficient of variation of 42.45 per cent, while cotton yield had a coefficient of variation of 25.83 per cent. Decompositionanalysis further reveals that the contribution of yield effect to cotton production in India ranged from 145.27 per cent inone period to -39.22 per cent in another period. The findings highlight significant growth in cotton area, production, andyield in India, although with some fluctuations and instabilities. Technological advancements were identified as the drivingforce behind the increased cotton production. The study emphasizes the importance of addressing production risks andsuggests policies that focus on improving yield to further enhance cotton production in India.

Thermo-catalytic decomposition of cotton seed press cake over nickel doped zeolite Y, hydrogen: enhanced yield of bio-oil with highly selective fuel-range hydrocarbons.

This research reports the yield of bio-oil from cotton seed press cake (CSPC) via an optimized thermo-catalytic pyrolysis using nickel impregnated zeolite Y, hydrogen catalyst. The catalyst, raw biomass and catalyst impregnated biomass were characterized using different analytical techniques. The ideal temperature, duration, and catalyst concentration for pyrolysis experiments were determined to be 300 °C, 20 minutes, and 5% of Ni-doped zeolite Y, hydrogen, respectively, in order to achieve the best bio-oil yield (35%). Gas chromatography-mass spectrometry (GC-MS) of pyrolytic bio-oil depicted the presence of C2-C26 hydrocarbons. The findings of this investigation showed that the synthesis of bio-oil with highly selective fuel-range hydrocarbons could be efficiently induced through the pyrolysis of CSPC biomass employing nickel impregnated zeolite Y, hydrogen catalyst. Moreover, thermogravimetric analysis (TGA) of cotton seed press cake with catalyst was carried out at various heating rates to find out the kinetic parameters. Employing Kissinger model, activation energy (E a) and frequency factor (A) for various components of biomass i.e., hemicellulose, cellulose and lignin were calculated as 83.14 kJ mol-1, 99.76 kJ mol-1, 124.71 kJ mol-1 and 1.9 × 107 min-1, 1.0 × 108 min-1, 1.0 × 1010 min-1, respectively. It can be concluded from the results that cotton seed press cake waste has potential for use as a pyrolysis feedstock in large-scale bio-fuel production.

The Evolving E-cigarette: Comparative Chemical Analyses of E-cigarette Vapor and Cigarette Smoke.

Background: E-cigarette designs, materials, and ingredients are continually evolving, with cotton wicks and diverse coil materials emerging as the popular components of atomisers. Another recent development is the use of nicotine salts in e-liquids to replicate the form of nicotine found in cigarette smoke, which may help cigarette smokers to transition to e-cigarettes. However, scientific understanding of the impact of such innovations on e-cigarette aerosol chemistry is limited.Methods: To address these knowledge gaps, we have conducted a comparative study analyzing relevant toxicant emissions from five e-cigarettes varying in wick, atomiser coil, and benzoic acid content and two tobacco cigarettes, quantifying 97 aerosol constituents and 84 smoke compounds, respectively. Our focus was the potential for benzoic acid in e-liquids and cotton wicks to form aerosol toxicants through thermal degradation reactions, and the potential for nickel–iron alloy coils to catalyze degradation of aerosol formers. In addition, we analyzed e-cigarette emissions for 19 flavor compounds, thermal decomposition products, and e-liquid contaminants that the FDA has recently proposed adding to the established list of Harmful and Potentially Harmful Constituents (HPHCs) in tobacco products.Results: Analyses for benzene and phenol showed no evidence of the thermal decomposition of benzoic acid in the e-cigarettes tested. Measurements of cotton decomposition products, such as carbonyls, hydrocarbons, aromatics, and PAHs, further indicated that cotton wicks can be used without thermal degradation in suitable e-cigarette designs. No evidence was found for enhanced thermal decomposition of propylene glycol or glycerol by the nickel–iron coil. Sixteen of the 19 FDA-proposed compounds were not detected in the e-cigarettes. Comparing toxicant emissions from e-cigarettes and tobacco cigarettes showed that levels of the nine WHO TobReg priority cigarette smoke toxicants were more than 99% lower in the aerosols from each of five e-cigarettes as compared with the commercial and reference cigarettes.Conclusions: Despite continuing evolution in design, components and ingredients, e-cigarettes continue to offer significantly lower toxicant exposure alternatives to cigarette smoking.

Forest management impacts on stream integrity at varying intensities and spatial scales: Do biological effects accumulate spatially?

The effects of forest harvesting on headwaters are quite well understood, yet our understanding of whether impacts accumulate or dissipate downstream is limited. To address this, we investigated whether several biotic indicators changed from smaller to larger downstream sites (n = 6) within three basins that had intensive, extensive or minimal forest management in New Brunswick (Canada). Biofilm biomass and grazer abundance significantly increased from upstream to downstream, whereas organic matter decomposition and the autotrophic index of biofilms decreased. However, some spatial trends differed among basins and indicated either cumulative (macroinvertebrate abundance, predator density, sculpin GSI) or dissipative (autotrophic index, cotton decomposition) effects downstream, potentially explained by sediment and nutrient dynamics related to harvesting. No such among-basin differences were observed for leaf decomposition, biofilm biomass, macroinvertebrate richness or sculpin condition. Additionally, results suggest that some of the same biological impacts of forestry observed in small headwaters also occurred in larger systems. Although the intensive and extensive basins had lower macroinvertebrate diversity, there were no other signs of biological impairment, suggesting that, overall, current best management practices protect biological integrity downstream despite abiotic effects.

An environmentally friendly approach to fabricating flame retardant, antibacterial and antifungal cotton fabrics via self-assembly of guanazole-metal complex

Cotton fabrics are prone to ignite fire accidents as well as breed bacteria and fungi, which have hampered their applications in the field of packaging and home decorations. Guanazole complexes with silver and zinc ions were deposited to cotton fabrics through self-assembly to prepare the flame-retardant and antibacterial cotton fabrics. The effect of the guanazole-metal complexes on the morphological structure, flammability and thermal degradation of cotton fabrics was studied by field emission scanning electron microscopy, limiting oxygen index (LOI), UL-94 vertical burning test, and thermogravimetric analysis. The antibacterial and antifungal activities of the coated fabrics were evaluated as well. The guanazole-zinc and guanazole-silver treated cotton fabrics showed a high LOI of 29.5% and 27.5%, respectively. In the vertical burning test, both the guanazole-zinc and guanazole-silver treated cotton fabrics self-extinguished when removing the ignition source, displaying a UL-94 V-0 classification, while the untreated one and the guanazole-treated one burned out. Thermogravimetric analysis results confirmed that the guanazole-metal complexes promoted the thermal decomposition of cotton and thus improved the char yield significantly. Micro-scale combustion calorimeter measurements clarified that the guanazole-zinc and guanazole-silver treated cotton displayed dramatically decreased peak heat release rate (64.4% and 59.1%, respectively) and total heat release (26.4% and 14.8%, respectively) in comparison to the untreated one. The significantly improved flame retardancy of guanazole-metal complexes treated cotton fabrics could be attributed to their enhanced charring capability that blocked flammable volatiles into flame zone. The treated cotton fabrics with guanazole-metal complexes exhibited better antibacterial capacity against Staphylococcus aureus and Escherichia coli than the untreated and guanazole-treated ones. Furthermore, the guanazole-silver treated cotton fabrics also showed good antifungal activity against Penicillium, Fusarium chlamydosporum and Aspergillus niger.

Exploring temporal and spatial variation in cotton tensile-strength loss to assess the ecosystem health of non-wadeable rivers

Abstract Cotton strip assays are becoming a widely utilised functional indicator to assess and interpret ecosystem health of non-wadeable rivers. Cotton decomposition may be sensitive to seasonal variation in key drivers, the aim of this study therefore, was to elucidate the temporal variation in cotton strip decomposition across a land-use gradient to underpin the utility of this technique as an indicator. Twelve sites, spanning a range of water quality, related to upstream land-use intensity were sampled monthly for 16 months. Mean cotton tensile-strength loss per day ranged from 0.8% to 13.2% per day across the study sites. Cotton tensile-strength loss was significantly related to mean water temperature, the concentration of dissolved nutrients, water clarity, and dissolved ions, in linear mixed models (all p

Thermal decomposition of chemically treated cellulosic fibers

The thermal decomposition of cotton and hemp fibers was studied after mild alkaline treatments with tetramethyl-, tetraethyl- and tetrabutylammonium hydroxides with the goal of modeling the chemical activation during carbonization of cellulosic fibers. The thermal decomposition was studied by thermogravimetry/mass spectrometry and pyrolysis–gas chromatography/mass spectrometry (Py–GC/MS). The treated samples decomposed in two temperature ranges during heating in the thermobalance. At lower temperature, tetraalkylammonium hydroxides (TAAH) ionically bonded to the cellulose molecules were decomposed; moreover, the alkaline agents initiated the partial decomposition of cellulose. Those fiber segments, which were not accessible for TAAH, decomposed at similar temperatures as the original cotton and hemp samples. It is known that quaternary ammonium hydroxides swell the cellulosic fibers; however, the results of this study proved that there was a chemical interaction between the alkaline swelling agents and cotton or hemp fibers at rather low temperatures (200–300 °C). The evolved products indicated that the alkaline chemicals reacted with the cellulose molecules and alkylated compounds were formed. This observation was confirmed by thermochemolysis experiments carried out by Py–GC/MS using tetramethylammonium hydroxide reagent. The thermochemolysis experiments under mild conditions resulted in the methylation of the glucoside units and levoglucosan, and no peeling reactions of the sugar units were observed as during strong alkaline conditions described in the literature.

High rates of organic carbon processing in the hyporheic zone of intermittent streams

Organic carbon cycling is a fundamental process that underpins energy transfer through the biosphere. However, little is known about the rates of particulate organic carbon processing in the hyporheic zone of intermittent streams, which is often the only wetted environment remaining when surface flows cease. We used leaf litter and cotton decomposition assays, as well as rates of microbial respiration, to quantify rates of organic carbon processing in surface and hyporheic environments of intermittent and perennial streams under a range of substrate saturation conditions. Leaf litter processing was 48% greater, and cotton processing 124% greater, in the hyporheic zone compared to surface environments when calculated over multiple substrate saturation conditions. Processing was also greater in more saturated surface environments (i.e. pools). Further, rates of microbial respiration on incubated substrates in the hyporheic zone were similar to, or greater than, rates in surface environments. Our results highlight that intermittent streams are important locations for particulate organic carbon processing and that the hyporheic zone sustains this fundamental process even without surface flow. Not accounting for carbon processing in the hyporheic zone of intermittent streams may lead to an underestimation of its local ecological significance and collective contribution to landscape carbon processes.

Permanent flame retardant finishing of textiles by allyl-functionalized polyphosphazenes.

Despite their excellent flame retardant properties, polyphosphazenes are currently not used as flame retardant agents for textile finishing, because a permanent fixation on the substrate surface has failed so far. Here, we present the successful synthesis and characterization of a noncombustible and foam-forming polyphosphazene derivative, that can be immobilized durably on cotton and different cotton/polyester blended fabrics using photoinduced grafting reactions. The flame retardant properties are improved, a higher limiting oxygen index is found, and the modified textiles pass several standardized flammability tests. As flame retardant mechanism a synergistic effect between the immobilized polyphosphazene and the textile substrate was observed. The polyphosphazene finishing induces an earlier decomposition of the material with a reduced mass loss in thermogravimetric analysis. The decomposition of cotton and polyester leads to the formation of phosphorus oxynitride, which forms a protecting barrier layer on the fiber surface. In addition, the permanence of the flame retardant finishing was proven by laundry and abrasion tests.

Response of stream ecosystem function and structure to sediment metal: Context-dependency and variation among endpoints

Abstract Physicochemical and ecological attributes of ecosystems (i.e., environmental context) can modify the exposure and effects of metals, which presents a challenge for ecosystem management. Furthermore, the functional and structural attributes of an ecosystem may not respond equally to metals or be uniformly responsive to environmental context. We explored how physicochemical and ecological context modified sediment metal dose-response for a suite of functional and structural measures. Two sediments with high (HB) and low (LB) acid volatile sulfide and organic carbon content (i.e., physicochemical context) were amended with copper and nickel to establish a gradient of treatments from non-toxic to potentially toxic. Sediments were deployed in each of two streams (i.e., ecological context), incubated for four weeks, and measured for sediment microbe, biofilm, and macroinvertebrate dose-response to metal. The dose-response of microbial function was affected by physicochemical context, with cotton decomposition negatively related to sediment metal only on LB sediments. The abundance of invertebrates from the orders Ephemeroptera, Plecoptera, and Trichoptera (EPT) responded negatively to sediment metal only on LB sediments; however, this dose-response was only observed in one stream, likely because of greater abundance of sensitive EPT taxa (i.e., Baetidae and Ephemerellidae). Biofilm structure was negatively affected by sediment metal in only one stream and there was no difference in dose-response between the two sediment types. Biofilm function was affected by sediment type and stream; production by biofilms exposed to HB sediment was negatively related to sediment metal in only one stream. In all, the majority of our endpoints exhibited responses that were modified by environmental context; however, each component of the ecosystem exhibited unique context dependency. For management of sediment metals, an understanding of context dependency is useful for informed decision-making, but the application of simple contextual filters are unlikely to protect all elements of an ecosystem.

Hollow Porous Carbon Fiber from Cotton with Nitrogen Doping.

Porous carbon fiber with hollow structure and hydrophilic groups was successfully prepared from cotton. The structures and surface chemical properties of the porous carbon fiber were characterized by nitrogen adsorption isotherms, thermogravimetry, FTIR spectroscopy, and scanning electron microscopy. The morphologies of porous carbons prepared under different conditions were observed and compared. The resulting porous carbons had a microporous structure with a pore size distribution around 0.7-2.0 nm. The pyrolysis and decomposition of cotton to form a condensation cross-linked ring structure took place from 230 to 350 °C. Nitrogen-containing groups could be incorporated into the carbon matrix by urea decomposition during the carbonization process. The porous carbon contained more hydrophilic groups and its fiber structure was kept; the carbon yield was improved in the presence of KOH/urea. The porous carbon fiber showed high adsorption capacities of CO2 as a result of its surface hydrophilic groups and developed pore structure.

Effect of nitrogen additives on thermal decomposition of cotton

As a part of investigation of phosphorus–nitrogen synergistic flame retardancy of cotton fabrics, functions of three nitrogen compounds, urea (UR), guanidine carbonate (GC), and melamine formaldehyde (MF), were studied. The cotton fabrics treated by three compounds exhibited different thermal degradation patterns but similar limiting oxygen indexes, proven nitrogen compounds alone have no significant flame retardant effect on cellulose. The thermal decompositions of the nitrogen compounds were different during the pyrolysis and combustion. UR decomposed quickly and releases large amount of ammonia and other non-flammable gases, while MF promoted char formation with cellulose. GC exhibited both gas releasing and char formation on cotton under heat. Activation energy of decomposition of GC and MF treated cotton was more than the untreated cotton and lower for UR treated cotton. UR and GC treated cotton showed decrease in heat of combustion values and that of MF treated cotton showed an increase in values as compared to untreated cotton. Fourier transform infrared spectra (FTIR) analysis of chars obtained after thermal gravimetric analyses (TGA) treatment showed presence of nitrogen in the char bonded chemically as heterocyclic. Chars of MF and GC treated fabrics contain more C–N bond as compared to UR treated fabrics indicating greater interaction of GC and MF with cellulose during thermal decomposition.

Effect of phosphorus flame retardants on thermo-oxidative decomposition of cotton

The effect of six organophosphorus compounds, including Pyrovatex CP (PCP), diammonium phosphate (DAP), phosphoric acid (PA), tributyl phosphate (TBP), triallyl phosphate (TAP) and triallyl phosphoric triamide (TPT) on the flame retardancy of cotton cellulose was studied. PCP, PA, and DAP are more efficient compared with the other three compounds in improving the limiting oxygen index (LOI) of cotton. The effectiveness of these compounds was investigated using scanning electron microscope (SEM) images of char formed after LOI tests, char content, activation energy of decomposition and heat of combustion data. SEM images showed that DAP, PCP and PA chars maintain the surface morphology during the burning process, which might be due to the formation of a protective layer or crosslinking effect. PA, PCP, and DAP treated fabrics have a higher activation energy of decomposition, higher char content and lower heat of combustion.

Model-free method for evaluation of activation energies in modulated thermogravimetry and analysis of cellulose decomposition

In modulated thermogravimetry the classical linear temperature–time relationship is perturbed by sinusoidal temperature oscillations of small amplitude. Mass loss and its hypothetical unperturbed derivative are connected by an integral equation with the kernel expressed as the ratio of Arrhenius exponentials with the perturbed and unperturbed temperature in the numerator and denominator, respectively. The solution of this equation by the least-squares method gives activation energy, E. The method is model-free, since E is determined on the basis of the experiment without any theoretical functions. Such a method has been applied to study the decomposition of cotton in air. The plot of activation energy versus the degree of conversion, α , shows that the decomposition is characterized at least by three successive processes. The first one ( ≅ 5 % of mass loss) with E ≅ 90 – 167 kJ mol - 1 can be attributed to the formation of the ether bond between hydroxymethyl groups and hydroxyls in adjacent chains of cellulose an/or to oxidation of chain ends and products of cellulose decomposition. The second process with E ≅ 195.9 kJ mol - 1 over the range 0.2 < α < 0.62 is the first rate-limiting step attributed to depolymerization of cellulose by transglycosylation. The third process with E = 153.1 kJ mol - 1 over the range 0.7 < α < 1 is again the rate-limiting step. It corresponds to the oxidation of the carbon matrix of partly (or completely) carbonized cellulose. Plateaus in E ( α ) can be used to predict the mass loss and provide valuable information about chemistry of decomposition.

Modulated thermogravimetry in analysis of decomposition kinetics

Optimal constants in physicochemical models describing decomposition kinetics are searched for from thermogravimetric information by the method of nonlinear regression. The method requires an iterative numerical solution of differential equations for non-isothermal kinetics. The technique of conjugate functions is used to provide a fast quadratic convergence of the iterations. The method is described in detail for the cases where input information represents either derivatives of mass loss or perturbations of these derivatives caused by sinusoidal modulation of linear temperature–time relationships. In both cases two-stage decomposition with two parallel (independent) reactions is considered as a numerical example. The discussion is mainly focused on the analysis of the perturbations (modulations). In the case of modulated thermogravimetry, a relative error in the calculated activation energy is approximately equal to a relative error in the approximation of the perturbations. That is why activation energy can be calculated with high accuracy. Moreover, the conclusion about the adequacy of evaluated models can be made immediately after a visual verification of the approximation error. Two-stage decomposition of cotton is used as an experimental example. The only curve of the perturbations measured at one heating rate is used for calculating the kinetic constants. This curve contains information about mass loss in the hidden form. Nevertheless, one can ensure that the used mathematical models with the obtained kinetic constants are able to approximate not only the curve of mass loss subjected to the handling but also a curve measured at another heating rate. The high predictive force of modulated thermal analysis promises to be an obvious alternative to the classical technique. The weak sensitivity of predictions made by modulated thermogravimetry to a form of models used is a very important distinction for the wide application of this analysis in different fields of chemical engineering.

Characteristics of thermooxidative decomposition of cotton and polyester blends

The characteristics of thermooxidative degradation of materials made of cellulose (cotton) and polyester fibre blend are established, consisting of alteration of the dynamics and temperature range of liberation of combustible gases and reducing the self-ignition temperature. It is shown that T-3 fireproofing compound is an effective combustion retardant for materials made of cellulose and polyester fibre blends, since it inhibits oxidative processes in the self-ignition temperature range of combustible products and has high carbonizing power.

Winter decomposition of transgenic cotton residue in conventional-till and no-till systems

Current research suggests that genetic modification of commercial crops may lead to indirect effects on ecosystem function (i.e. decomposition and nutrient cycling processes). We investigated residue decomposition of cotton that was genetically modified to express an endotoxin insecticide isolated from Bacillus thuringiensis ( Bt) and/or glyphosate tolerance (Roundup Ready ®). Decomposition of the genetically modified residue was compared within agricultural systems under conventional-tillage (CT) or no-tillage (NT) management. We tested for variation in decomposition dynamics under the two tillage regimes because there are intrinsic differences in environmental and biotic conditions between them, and that both management methods are employed in cotton production. We hypothesized that decomposition dynamics would be affected by the presence or absence of the Bt endotoxin and that the degree of variation would be more distinct between tillage regimes. Decomposition dynamics were determined by change in mass remaining and nutrient content (C and N) of cotton litter material contained in mesh litterbags collected over a 20-week period from December to May. Rate of decomposition and change in nutrient content of decomposing litter within either tillage regime was not significantly different between the two cotton types examined. Percent mass remaining, total N and total C decreased over time and were significantly different between tillage regimes only. Over the 20-week experiment, mass loss with subsurface decomposition in the CT reached 55% but surface decomposition in the NT reached only 25%. We observed that cotton genetically modified to express Bt endotoxin and glyphosate tolerance decomposed similarly to cotton modified for glyphosate tolerance only.

Decomposition of cotton by Trichoderma species: influence of temperature, soil type, and nitrogen levels

The effect of temperature on the ability of five species of Trichoderma to decompose cellulose was evaluated in three types of sterilized soils. The loss in tensile strength of cotton strips was used as an index of cellulose decomposition. The influence of levels of nitrogen on cotton degradation was also evaluated using silica sand as a substitute for soil. A greater loss in cotton tensile strength was obtained with T. virens and T. viride than with T. hamatum, T. polysporum, or T. koningii. All species responded similarly to nitrogen levels and temperature, with decreased activity at low nitrogen and low temperature. The soil also had a large influence on the rate of decomposition of the strips. The soil from a maple forest gave rise to greater losses in tensile strength than did soil from a white pine or Norway spruce plantation. These results emphasize the importance of the soil chemistry in determining fungal activities in the field, and the difficulties of extrapolating results of cellulose utilization studies in the laboratory to the field.Key words: Trichoderma, cellulolysis, soil, nitrogen, temperature.

Use of cotton strips to relate fungal community structure to cellulose decomposition rates in the field

Studies on the ecology of soil fungi have traditionally been concerned with the distribution of taxa in the soil, and the influence of the environment on community structure and composition. Relatively little emphasis has been placed on the role of the fungal community and the effects of community composition on decomposition processes, even though it is recognized that the decomposition of natural compounds is a major function of the fungal community. One approach to defining the role of soil fungi in the decomposition process is to take an inventory of the fungi in the soil, evaluate their enzymatic capacity under laboratory conditions and then use these data to make inferences about the role of the community in decomposition of natural substrates, as has been done by Flanagan and Scarborough (1974) and Gochenaur (1984). Using this approach, and comparing soils, Flanagan (198 1) concluded that “it appears that taxonomic differences in fungal communities between ecosystems do not significantly influence the decay rate of plant remains between sites. The biomass of fungi is related to quantity and quality of organic matter, and the decay rate of a given organic matter is controlled primarily by climates”. Although such studies provide useful information, they suffer from the fact that soil fungi are being tested under artificial conditions for their potential for decomposing specific substrates. To interpret the role of fungal community structure on actual decomposition rates, it would be better to examine fungi actually colonizing particular substrates, from the soil, and to monitor simultaneously the amount of decomposition that is taking place. An opportunity to do this arose as part of an ongoing study on the effects of amendments on the decomposition of cotton (cellulose) strips, buried in a Scottish moorland soil. Cotton strips of uniform weave, 1Ocm wide by 30 cm, were prepared (Latter and Howson, 1977) and inserted into an acid (pH 4.345) Scottish moorland soil near Banchory (Grid Ref. No. 637903). The general area of the study has been described in detail by Miles (1973). The top segments of the strips were placed in the old litter/F horizon, the side segments in the variable O/H/Ah horizon, and the bottom segments in the E/Es horizons (nomenclature according to Hodgson, 1974) using the method of French and Howson (1982). On 25 August 1981, five replicate strips were placed randomly in each of three plots that had been amended as follows: (i) N aDDlied as NH.NO, at a rate of 40 am-‘: (ii) P applied as KH;FCJ, at 60 gm-*, (iii) Ca applied& Ca;cb; at 100 g m-*. A further 5 strips were distributed between three plots treated with a 1: 1 mixture of glucose and potato starch: two in a plot treated at 4 g m-*, one in a plot treated at 16gm-* and the remaining two in a plot treated at 40 g m-*. Data from these three plots were combined as a single “carbohydrate” treatment. All amendments had been applied on three occasions during 1979; on 19 September, 15 October and 30 October. Five strips were also inserted in unamended control plots. The strips were removed on 8 December 198 1 and the side segments were cut, frayed and tested for tensile strength (Latter and Howson, 1977). Unburied control strips were simultaneously tested for tensile strength and the percent tensile strength loss for test strips was calculated as follows:

Thermal decomposition studies of cotton radiolytically grafted with phosphorus- and bromine-containing flame retardants

Thermal analysis of cotton samples grafted with triallylphosphate (TAP) and 2,2,2-tribromoethyl acrylate (TBEA) was carried out. Grafting of poly-TAP causes a significant decrease in the decomposition temperature of cotton. The cotton decomposition is acid catalyzed by H3PO4 formed during the decomposition of the grafted poly-TAP. The HBr evolved during decomposition was monitored continuously during thermal analysis of cotton grafted with poly-TBEA. No significant flame-retarding effect by HBr was found. Since grafted poly-TBEA causes a decrease in the decomposition temperature of cotton, it is suggested that the flame retardant mechanism for poly-TBEA in cotton occurs mainly in the solid phase before most of the HBr is released.