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Paper and packaging materials a lignocellulose-based natural biodegradable polymer that spontaneously releases acetic acid, aldehydes, alcohol, and ester-based volatile organic compounds (VOCs) upon ageing and these VOCs start degrading the paper products and decline their mechanical strength properties. The reactivity of the paper of unbleached wheat straw pulp towards acetic acid and hexanal, which has been proven to have more degrading effects on paper than other VOCs, was considered in this work. The papers were exposed to these volatile compounds for 90 days in an air-tight vessel under ambient environmental conditions. The results showed that hexanal was more destructive than acetic acid with regards to cellulose degradation and depletion in the mechanical strength properties. The paper properties like, tensile, tear and burst index, viscosity, pH and carbonyl group content was measured. The growth of the carbonyl group, evidence of the ageing effects in the paper, detected more in the paper exposed to acetic acid. However, the strength of paper properties declined more with hexanal. FE-SEM analysis of the sample showed the development of pores and damage of cellulose fibre upon ageing. Similarly, the damaging effects of VOCs on cellulose, hemicelluloses and lignin were confirmed by significantly reduced peak detection through FT-IR \analysis. The high crystallinity index of the paper products due to exposure to VOCs was detected by XRD analysis, which confirmed the degradation of the low molecular weight cellulose molecule. Thus, the results are strongly recommended that VOCs that generates due to natural or artificial ageing could be the leading cause of paper degradation. [ABSTRACT FROM AUTHOR]

Background: Paper mulberry is a promising alternative fodder source due to its high protein and the abundance of active components. However, paper mulberry often faces susceptibility to contamination during silage fermentation, and there is a need to improve the quality of silage fermentation of paper mulberry through exotic additives. Sea buckthorn pomace (BP) is a feed additive containing antimicrobial and antioxidant substances that help to enhance silage fermentation. Therefore, the objective of this study was to evaluate the effects of BP and Lactiplantibacillus as additives on silage fermentation and bacterial community of paper mulberry. Results: The results showed that BP and Lactiplantibacillus significantly reduced the pH and ammonium nitrogen content of paper mulberry silage (P < 0.05) and significantly increased the content of lactic acid and acetic acid (P < 0.05), resulting in more residual water-soluble carbohydrate and crude protein contents and less fiber content relative to the control. The key microorganisms in paper mulberry silage fermentation are Lactiplantibacillus pentosus and Weissella cibaria. Among these, Lactiplantibacillus favored a rapid increase in Lactiplantibacillus pentosus abundance during the pre-silage fermentation period, whereas BP favored the promotion of Lactiplantibacillus pentosus growth, resulting in higher contents of lactic and acetic acid than those of the control. Conclusions: Simultaneously adding Lactiplantibacillus and BP can effectively improve the quality of paper mulberry silage and increase the abundance of beneficial microorganisms in paper mulberry silage. [ABSTRACT FROM AUTHOR]

Samples of papers artificially (2 to 60 days) and naturally (10, 45, and 56 years) aged were studied by the Py-GC/MS method to identify decomposition products. Possible reaction scenarios for cellulose degradation were developed. One of the degradation products is acetic acid, which can (auto)catalyze the cleavage of cellulose β(1→4)-glycosidic bonds of cellulose polymer chains. However, during 20 s of Py-GC/MS analysis, temperatures of up to 300 °C did not significantly increase or modify the formation of decomposition products of paper components. At 300 °C, the amount of several cellulose decomposition products increased regularly depending on the number of days of artificial aging and natural aging, demonstrated mainly by the generation of 2-furancarboxaldehyde, 5-hydroxymethylfurfural, and levoglucosan and its consecutive dehydration products. No correlation between the amount of lignin decomposition products and the time of aging was found when the pyrolysis was performed at 300 °C and 500 °C. Compounds present in the products of decomposition at 500 °C bear the imprint of the chemical composition of the sampled paper. Pyrograms taken at 300 °C using the Py-GC/MS method can give additional information on the changes in the chemical structure of paper during natural or artificial aging, mainly about the cleavage of β(1→4)-glycosidic bonds during aging. [ABSTRACT FROM AUTHOR]

The aim of this study was to assess the changes in chemical and physical properties of selected paper documents, dating from the 18th century to the present date. Paper documents from the 18th, 19th, and 21st centuries had a pH ranging from slightly acidic to alkaline values, whereas paper documents from the 20th century were more acidic. The contents of mannose, glucose, holocellulose, and lignin were significantly correlated with the pH of the paper. High contents of both carboxylic acids (acetic and formic) and the most durable monosaccharide (glucose) were found in the oldest examined paper documents originating from the 18th and 19th centuries. The lowest percentage of brightness was found in paper documents originating from 1920 and 1923. The lowest breaking length was associated with papers originating from 1920.

The aim of this study was to assess the changes in chemical and physical properties of selected paper documents, dating from the 18th century to the present date. Paper documents from the 18th, 19th, and 21st centuries had a pH ranging from slightly acidic to alkaline values, whereas paper documents from the 20th century were more acidic. The contents of mannose, glucose, holocellulose, and lignin were significantly correlated with the pH of the paper. High contents of both carboxylic acids (acetic and formic) and the most durable monosaccharide (glucose) were found in the oldest examined paper documents originating from the 18th and 19th centuries. The lowest percentage of brightness was found in paper documents originating from 1920 and 1923. The lowest breaking length was associated with papers originating from 1920. [ABSTRACT FROM AUTHOR]

Aging of a power transformer’s insulation system produces carboxylic acids. These acids—acetic, formic and levulinic—are absorbed by the paper insulating material, thus accelerating the degradation of the whole insulation system. In this contribution, the effect of these acids on the aging of oil-impregnated paper insulation used in power transformer is reported. A laboratory aging experiment considering different concentrations of these three acids was performed to assess their effect on the insulation system’s degradation. Each acid was individually mixed with virgin oil, and a mixture of acids was also blended with oil. The paper’s degradation was assessed by the degree of polymerization (DPv). It was found that the DPv of paper aged with formic acid decreased much faster in comparison to the other acids.

One of the problems of papers and cardboards in the packaging industry is the poor resistance to water, gas, and oil penetration. Nowadays, many researches have been done on the use of biodegradable films and coatings based on polysaccharides to solve this problem. Chitosan is one of these polysaccharides that can be used as a biodegradable coating in packaging papers. In this study, the effect of chitosan on the strength and barrier properties of coated liner paper was investigated. Chitosan was used in three levels of 10, 15, and 20 g/L acetic acid (1%) and with two softener ratios (glycerol) of 0.5 and 1 (based on dry weight of chitosan) for papers coating. Strength properties including tensile, burst and tear index and barrier properties including water absorption, air resistance, and oil absorption in the coated samples were investigated. The statistical analysis of results showed that the barrier properties increased significantly. Also, the effect of increasing the concentration of softener in the coating solution on the properties of air resistance and oil absorption was positive but negative for water absorption. The basis weight, burst and tear index of the coated samples increased with increasing coating weight. On the other hand, the tensile strength decreased. Moreover, increasing the concentration of softener in the coating solution showed a negative effect on the properties of the samples. The scanning electron microscope images showed the formation of chitosan film and increase in the uniformity of the liner paper surfaces, especially in higher consumption volume. [ABSTRACT FROM AUTHOR]