Strengthening Regenerated Cellulose Fibers Sourced from Recycled Cotton T-Shirt Using Glucaric Acid for Antiplasticization

The recycling of cellulose from cotton textiles would minimize the use of virgin crop fibers, but recycled polymers are generally inferior in mechanical performance to those made from virgin resins. This challenge prompted the investigation of biobased additives that were capable of improving the mechanical properties of fibers by means of antiplasticizing additives. In this study, regenerated cellulose (RC) fibers were spun from cellulose found in cotton T-shirts, and fibers were mechanically strengthened with glucaric acid (GA), a nontoxic product of fermentation. The recycled pulp was activated using aqueous sodium hydroxide and then followed by acid neutralization, prior to the direct dissolution in lithium chloride/N,N-dimethylacetamide (LiCl/DMAc) at 3 wt.% cellulose. At 10% (w/w) GA, the tensile modulus and strength of regenerated cellulose from recycled cotton fibers increased five-fold in contrast to neat fibers without GA. The highest modulus and tenacity values of 664 cN/dtex and of 9.7 cN/dtex were reported for RC fibers containing GA.

Effect of the Dissolving Method on the Dissolution of Dissolving Pulp Cellulose Fibers with Different Dried-States in Different NaOH/additives Aqueous Solutions

A NaOH/urea (or thiourea) solvent system capable of dissolving cellulose at lower temperatures is a breakthrough in cellulose chemistry, and it was reported that cellulose rapidly dissolved when it was added to a precooled aqueous solution of sodium hydroxide (NaOH) and additives. Therefore, this work compared the effectiveness of the direct dissolution method and freezing-thaw method in dissolving pulp fiber and pure cellulose. Three aqueous solutions were examined: 7% NaOH/12% urea, 9.5% NaOH/4.5% thiourea, and 8% NaOH/8% urea/6.5% thiourea. The dissolving capacity of three NaOH/additives aqueous solutions was analyzed by polarized optical microscopy and the dissolved cellulose proportion was determined. The results showed that the never-dried softwood dissolving pulp and bamboo dissolving pulp achieved better dissolution using freezing-thaw method than using direct dissolution method in the three aqueous solutions. The dissolving method had a negligible effect on the dissolution of each dissolving pulp in the 8% NaOH/8% urea/6.5% thiourea solution. It seems that the direct dissolution method was more suitable for oven-dried microcrystalline cellulose with a low degree of polymerization (DP) and the freezing-thaw method was more suitable for never-dried pulp cellulose fibers with a higher DP.

Total reflection X-ray fluorescence analysis of aerosol particles with direct dissolution of the collection filter on a substrate

In this study, a novel method based on total reflection X-ray analysis was developed for determining the trace elements in aerosol particles.

Break-up of the Yugoslav political elite, 1962-1972

The break-up of the Yugoslav communist elite, which came about in the period 1962-1972, is considered. The break-up came about under the elite?s disappointment due to the failure to achieve economic objectives it set for itself, bringing about internal dubiety and mutual suspicion, the political system moving towards consociation also contributed to fracturing. However, this is not sufficient as explanation. Cultural elites also contributed in the same direction. Economic growth was significant, considering the entire period 1945-1991, but it was always clouded by imbalances. Certain issues and discussions were indicative of the break-up. Political unity and communism was gradually replaced as objective by ?resolving the national question?, also a legitimate Marxist concern. It can be considered that by the break-up, a normalization of elite pattern came about, comparable to elites in the greatest number of European states, although the elites kept on being ?ideocratic?. Whereas elites may have become ?normal?, the functioning of the political system became ever more difficult. The ascending national communist elites never undertook steps at the direct dissolution of the Yugoslav state, although they entered into ceaseless disputes and finally paved the way to ethnic entrepreneurs and counter-elites to implement the dissolution. By the elite break-up a relation between elite and nation similar to the one existing in the great majority of European countries was achieved.

Direct dissolution of UO2 in carboxyl-functionalized ionic liquids in the presence or absence of Fe-containing ionic liquids

Direct dissolution of UO2 in carboxyl-functionalized ionic liquids was achieved, and the addition of Fe-containing ionic liquids would improve the dissolution kinetics.