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The paper is on introducing carbamate groups in sheets of cellulose fiber assemblies by pad-dry-cure treatments with aqueous solutions of polyethylene glycol, amide and salt. The effects of process variables-on carbamation levels and on mechanical properties of the substrate-are reported. Depending on treatment conditions, the nitrogen contents in substrates are in the range 0.668-2.252 wt%, corresponding to nominal degrees of carbamate group substitution of 0.08-0.28. The carbamation is initiated at 140 °C curing, and the levels rise with temperature up to 220 °C, but decrease at higher temperatures. The duration of curing also exerts an influence. There is a catalytic effect of sodium acetate on the carbamation, but the salt also induces a brown coloration in samples, which is likely a result of Maillard-type reactions. The treatments cause hydrolytic degradation in substrates, but there are options to adjust treatment conditions and minimize damage. Pad-dry-cure treatments are a common operation in the textile and paper industries, and the process may be adopted in commercial-scale operations to create derivatized paper or fabrics (woven, knitted or non-woven) for utilization in applications such as adsorbents for heavy metals from waste water, in hygiene products, in the creation of flame retardant products, or in creating all-cellulose composites by further treatment with alkali. [ABSTRACT FROM AUTHOR]

This article describes a facile method for the preparation of cellulosic catalyst paper: the in situ synthesis of gold nanoparticles (AuNPs) on zinc oxide (ZnO) whiskers, the preferential support for AuNPs, preloaded into a paper matrix. The ZnO paper composites were fabricated using a high-speed and low-cost paper-making technique, and immersed in an aqueous solution of HAuCl4. After drying, fine 5 nm AuNPs were successfully formed on the ZnO whiskers inside the paper matrix. As- prepared AuNPs@ZnO whisker-containing paper (AuNPs@ZnO paper) is similar to ordinary paper products, being flexible, lightweight, and easy to handle. The AuNPs@ZnO paper exhibited a high catalytic efficiency towards the reduction of 4-nitrophenol to 4-aminophenol in aqueous media. Furthermore, the addition of a polyamideamine epichlorohydrin resin provided a wet strength to the AuNPs@ZnO paper, which enables several catalyst recycles with no significant losses in catalytic activity. [ABSTRACT FROM AUTHOR]

Acid catalyzed ageing of oil impregnated kraft paper has been studied experimentally. Five different carboxylic acids (formic, acetic, laevulinic, stearic and naphtenic acid) have been added to mineral oil to arrive at a neutralization value of 0,4 mg KOH/g. Thereafter, kraft paper of two different humidities has been allowed to equilibrate with the oil. The results show that the lower the molecular weight of the carboxylic acids is the more is absorbed by the paper. Furthermore, a clear synergy for the paper ageing rates between moisture and the lower molecular weight acids is found, while for the higher molecular weight acids almost no effects were found. It is concluded that present techniques for measuring acidity of oils do not reflect these detailed conditions. It is suggested to introduce a new measuring technique for neutralization value where water rinsing is used to identify the content of low molecular weight, water soluble acids. [ABSTRACT FROM AUTHOR]