Accelerated ageing of paper: effect of lignin content and humidity on tensile properties

AbstractPaper degradation menaces the useful lifetime of books, manuscripts, and works on paper during storage, circulation, and display in libraries, archives, and museums. Severe damages such as embrittlement, decay, and mold often occur to the paper that might threaten to lose cultural heritage. However, the shelf life of papers stored in suitable conditions can be extended by hundreds of years. The most important external factors affecting the deterioration of paper-based materials include, in particular, changes in temperature and air humidity. In this study, the effects of accelerated aging under different conditions, including substantially different relative humidity, were considered relative to the strength properties of the paper sheets. These include the mechanical strength, such as breaking length, tear resistance, and bursting strength of the paper samples before and after dry heat aging and hydrothermal aging. Samples with various content of lignin produced in neutral pH were examined to exclude the adverse influence of acidity on paper properties. The results indicate that impact of moisture on tensile properties and pH-value of paper is much greater than the effect of increased temperature. The results of this work are intended to consolidate and expand the theoretical foundation and provide technical support for the conservators and library staff on the storage of paper cultural relics.

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Effect of Yerba Mate and Silk Fibroin Nanoparticles on the Migration Properties in Ethanolic Food Simulants and Composting Disintegrability of Recycled PLA Nanocomposites

Polymers ◽

10.3390/polym13121925 ◽

2021 ◽

Vol 13 (12) ◽

pp. 1925

Author(s):

Freddys R. Beltrán ◽

Marina P. Arrieta ◽

Diego Elena Antón ◽

Antonio A. Lozano-Pérez ◽

José L. Cenis ◽

...

Keyword(s):

Silk Fibroin ◽

Accelerated Aging ◽

Melt Processing ◽

Yerba Mate ◽

Scale Level ◽

Hydrothermal Aging ◽

Contact Materials ◽

Food Simulants ◽

Before And After ◽

Silk Fibroin Nanoparticles

The main objective of the present research is to study the effect of the incorporation of low amounts of silk fibroin nanoparticles (SFNs) and yerba mate nanoparticles (YMNs) on the migration phenomenon into ethanolic food simulants as well as on the disintegrability under composting conditions of mechanically recycled polylactic acid (PLA). Recycled PLA was obtained under simulated recycling conditions by melt processing virgin PLA into films and further subjecting them to an accelerated aging process, which involved photochemical, thermal, and hydrothermal aging steps followed by an intense washing step. SFNs were extracted from Bombyx mori cocoons and YMNs from yerba mate waste. Then, recycled PLA was melted, reprocessed, and reinforced with either 1%wt. of SFNs or YMNs, by melt extrusion, and further processed into films by compression molding. The obtained nanocomposites were exposed to ethanolic food simulants (ethanol 10% v/v, simulant A and ethanol 50% v/v, simulant D1) and the structural, thermal, and mechanical properties were studied before and after the exposure to the food simulants. The migration levels in both food simulants were below the overall migration limits required for food contact materials. The materials were disintegrated under simulated composting conditions at the laboratory scale level and it was observed that the nanoparticles delayed the disintegration rate of the recycled PLA matrix, but nanocomposites were fully disintegrated in less than one month.

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Influence of Alkali Treatment on Properties of Casein Grafted Acrylonitrile Fibers

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.233-235.2532 ◽

2011 ◽

Vol 233-235 ◽

pp. 2532-2535

Author(s):

Jing Gao

Keyword(s):

Mechanical Properties ◽

Ph Value ◽

Alkali Treatment ◽

Extrinsic Factors ◽

Factors Affecting ◽

Ph Values ◽

Alkali Solutions ◽

Finishing Process ◽

Before And After ◽

Intrinsic And Extrinsic Factors

Casein grafted acrylonitrile fibers were treated by different concentration alkali solutions. The fibers component were investigated using chemical analysis before and after alkali treatment. The effects of alkali pH value on homopolymer PAN, free casein, grafted casein and grafting degree of the fibers were discussed individually. At the same time, the mechanical properties of the fibers treated by alkali at various pH values were tested, and the intrinsic and extrinsic factors affecting fibers mechanical properties were analyzed. The results can play a certain reference role to the early manufacture and finishing process of casein grafted acrylonitrile fibers.

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Assessment of Inorganic Bonded Paperboards Produced from Kraft and Recycled Newsprint

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.668.322 ◽

2015 ◽

Vol 668 ◽

pp. 322-329

Author(s):

J.M. Owoyemi ◽

Babatunde Ajayi ◽

O.S. Ogunrinde

Keyword(s):

Low Cost ◽

Accelerated Aging ◽

Aging Treatment ◽

Accelerated Ageing ◽

Mixing Ratio ◽

Thickness Swelling ◽

Mixing Ratios ◽

Kraft Paper ◽

Before And After ◽

Low Cost Housing

Homogeneous cement bonded paperboards were made with recycled newsprints and Kraft paper with ordinary Portland cement and curing reagent. Boards were produced at the blending proportions of 100:0, 50:50 and 0:100 respectively and at cement/ paper ratio of 1:1, 2:1 and 3:1 respectively. Dimensional movements were evaluated to investigate the effect of the variables used in board manufacturing before and after exposure to accelerated aging tests procedure. Increase in mixing ratio and blending proportion caused decrease in Thickness Swelling (TS) and Water Absorption (WA) while TS and WA of the untreated boards were lower than the accelerated aging treated boards. The dimensional movement of Kraft paper was higher than that of recycled newsprint before and after accelerated aging treatment. The strongest and most dimensionally stable board was produced at the highest level of cement/ paper ratio. The pre-accelerated ageing test carried out showed that mechanical properties were higher 2:1 and 3:1 paper cement mixing ratios. Kraft paper produced the strongest and most dimensionally stable board than recycled newsprint. From this study Kraft paper and recycled newsprint proved to be suitable for the manufacture of cement bonded paperboard capable of meeting the needs in core and low cost housing construction.

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Effect of Accelerated Ageing on the Mechanical and Structural Properties of the Material System Used in Protectors

Polymers ◽

10.3390/polym11081263 ◽

2019 ◽

Vol 11 (8) ◽

pp. 1263 ◽

Cited By ~ 1

Author(s):

Longina Madej-Kiełbik ◽

Katarzyna Kośla ◽

Dorota Zielińska ◽

Edyta Chmal-Fudali ◽

Magdalena Maciejewska

Keyword(s):

Structural Properties ◽

Accelerated Aging ◽

Accelerated Ageing ◽

Material System ◽

Wide Range ◽

Mechanical And Structural Properties ◽

Before And After ◽

Ft Ir ◽

Materials Used ◽

The Impact

Currently, there is a wide range of materials for motorcyclists available on the market that have a significant ability to absorb impact energy. Understanding the aging processes of materials is crucial for guaranteeing the long-term durability and safety of a new product. For this reason, the effect of accelerated aging on the mechanical and structural properties of the multifunctional materials used in commercial protectors was analyzed. The accelerated aging considered in this study simulated 3 years of use under real conditions. Then, DMTA and FT-IR research, as well as impact tests, were carried out on the commercially available protectors for motorcyclists, before and after the accelerated aging processes. Structural analysis using FT-IR showed no significant changes in the structure of the polymers used for producing the protectors. The DMA test results are consistent with those obtained from the impact study. Both methods showed that the samples maintain their protective properties, after accelerated aging. All of the examined protectors show that an increase in force is transferred through the sample, after the accelerated aging processes, but they still provide protection, according to the ISO standard.

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SEM Study of Tension Wood Fiber Morphology and its Effect on Paper Properties

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100079061 ◽

1977 ◽

Vol 35 ◽

pp. 308-309

Author(s):

K. W. Robinson

Keyword(s):

Tension Wood ◽

Wood Fiber ◽

Strength Properties ◽

Fiber Morphology ◽

Paper Properties ◽

Pure Cellulose ◽

Short Rotation ◽

Hardwood Trees ◽

Sem Study

Tension wood (TW) is an abnormal tissue of hardwood trees; although it has been isolated from most parts of the tree, it is frequently found on the upper side of branches and leaning stems. TW has been classically associated with geotropic alignment, but more recently it has been associated with fast growth. Paper made from TW is generally lower in strength properties. Consequently, the paper industries' growing dependence on fast growing, short- rotation trees will result in higher amounts of TW in the final product and a corresponding reduction in strength.Relatively few studies have dealt with the role of TW in the structure of paper. It was suggested that the lower strength properties of TW were due to a combination of factors, namely, its unique morphology, compression failures in the cell wall, and lower hemicellulose content. Central to the unique morphology of the TW fiber is the thick gelatinous layer (G-layer) composed almost entirely of pure cellulose.

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Does kraft hardwood and softwood pulp viscosity correlate to paper properties?

TAPPI Journal ◽

10.32964/tj15.10.643 ◽

2016 ◽

Vol 15 (10) ◽

pp. 643-651 ◽

Cited By ~ 1

Author(s):

ROBERT J. OGLESBY ◽

HUMPHREY J. MOYNIHAN ◽

RICARDO B. SANTOS ◽

ASHOK GHOSH ◽

PETER W. HART

Keyword(s):

Physical Properties ◽

Strength Loss ◽

Strength Properties ◽

Clear Correlation ◽

Paper Properties ◽

Physical Strength ◽

Pulp Viscosity ◽

Softwood Pulp ◽

The Impact ◽

Multiple recycling of paperboard: Paperboard characteristics and maximum number of recycling cycles— Part I: Multiple recycling of corrugated base paper

TAPPI Journal ◽

10.32964/tj18.11.631 ◽

2019 ◽

Vol 18 (11) ◽

pp. 631-638

Author(s):

FREDERIC KREPLIN ◽

HANS-JOACHIM PUTZ ◽

SAMUEL SCHABEL

Keyword(s):

Compression Test ◽

Production Capacity ◽

Strength Properties ◽

Paper Properties ◽

Corrugated Board ◽

Laboratory Conditions ◽

Base Paper ◽

Study Results ◽

Short Span ◽

Multiple Recycling

Paper for recycling is an important fiber source for the production of corrugated base paper. The change in production capacity toward more and more packaging papers affects the composition of paper for recycling and influences the paper quality. This research project investigated the influence of the multiple recycling of five different corrugated base papers (kraftliner, neutral sulfite semichemical [NSSC] fluting, corrugating medium, testliner 2, and testliner 3) on suspension and strength properties under laboratory conditions. The corrugated board base papers were repulped in a low consistency pulper and processed into Rapid-Köthen laboratory sheets. The sheets were then recycled up to 15 times in the same process. In each cycle, the suspension and the paper properties were recorded. In particular, the focus was on corrugated board-specific parameters, such as short-span compression test, ring crush test, corrugating medium test, and burst. The study results indicate how multiple recycling under laboratory conditions affects fiber and paper properties.

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An Empirical Investigation of Factors Affecting Stock Prices in Vietnam

Journal of Economics and Development ◽

10.33301/2014.16.01.05 ◽

2014 ◽

pp. 74-89 ◽

Cited By ~ 1

Author(s):

Vinh Vo Xuan

Keyword(s):

Exchange Rates ◽

Crude Oil ◽

Foreign Exchange ◽

Stock Prices ◽

Global Financial Crisis ◽

Oil Prices ◽

Foreign Exchange Rates ◽

Factors Affecting ◽

Crude Oil Prices ◽

Before And After

This paper investigates factors affecting Vietnam’s stock prices including US stock prices, foreign exchange rates, gold prices and crude oil prices. Using the daily data from 2005 to 2012, the results indicate that Vietnam’s stock prices are influenced by crude oil prices. In addition, Vietnam’s stock prices are also affected significantly by US stock prices, and foreign exchange rates over the period before the 2008 Global Financial Crisis. There is evidence that Vietnam’s stock prices are highly correlated with US stock prices, foreign exchange rates and gold prices for the same period. Furthermore, Vietnam’s stock prices were cointegrated with US stock prices both before and after the crisis, and with foreign exchange rates, gold prices and crude oil prices only during and after the crisis.

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Assessment of Color Stability of Treated Leathers with Silicone Oil and Polyethylene Glycol

Journal of African Leather and Leather Products Advances ◽

10.15677/jallpa.2014.v1i1.8 ◽

2014 ◽

Vol 1 (1) ◽

pp. 24-34

Author(s):

Alireza K. ◽

Hossein Ahmadi ◽

Mohsen Mohammadi

Keyword(s):

Ascorbic Acid ◽

Polyethylene Glycol ◽

Treatment Process ◽

Color Change ◽

Silicone Oil ◽

Accelerated Aging ◽

Color Stability ◽

Antioxidant Additive ◽

Before And After ◽

Aesthetic Values

Lubricants and leather dressings are the most common treatments of dry and water logged historical leathers. Color change has a great importance during the time and treatment process, due to visual and aesthetic values of historic leather relics. Polyethylene glycol (PEG) and silicone oil (SiO) are frequently used leather dressings in the conservation procedures. Therefore, color stability of treated leathers with PEG and SiO were investigated before and after heat accelerated aging. Moreover, application of ascorbic acid was evaluated as an antioxidant additive for PEG (PEG+AA).Color change after treatment and aging were studied by colorimetry technique in the CIE *L*a*b system. Results indicated to severe color alteration in PEG treated and aged leathers with or without ascorbic acid. Whereas, SiO treated samples showed better stability and minimum color shift after aging. Silicone oil was characterized as the best dressing for historical leathers with compared to PEG and PEG+AA, due to its high stability and aesthetical properties.

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MAGNESIUM ZK61A

Alloy Digest ◽

10.31399/asm.ad.mg0067 ◽

1969 ◽

Vol 18 (10) ◽

Keyword(s):

Corrosion Resistance ◽

Physical Properties ◽

Tensile Properties ◽

Room Temperature ◽

Heat Treating ◽

Strength Properties ◽

Casting Alloy ◽

Chemical Company ◽

Casting Alloys ◽

Magnesium Casting

Abstract Magnesium ZK61A is a heat treatable sand casting alloy offering higher strength properties for room-temperature applications than other magnesium casting alloys. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as casting, heat treating, machining, and joining. Filing Code: Mg-67. Producer or source: The Dow Chemical Company.

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