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Beneficiation of Sawdust Waste in the Context of an Integrated Forest Biorefinery Mill: Kraft and Prehydrolysis Kraft Pulping Properties
Published in Linda Godfrey, Johann F Görgens, Henry Roman, Opportunities for Biomass and Organic Waste Valorisation, 2020
JE Andrew, J Johakimu, P Lekha, ME Gibril, BB Sitholé
As part of a broader objective to isolate cellulose from sawdust waste material for the production of nanocrystalline cellulose, conventional industrially available processes such as the Kraft and pre-hydrolysis Kraft (PHK) processes were investigated for delignification of sawdust produced from E. grandis wood. Sawdust Kraft pulp yields (48%) and fibre morphologies were within acceptable ranges and comparable to conventional Kraft pulps produced from woodchips. The exception was the pulp strength properties such as burst, tear and tensile strengths, which were 50% to 70% lower than conventional pulps. Possible applications of this pulp could be addition or replacement of thermomechanical pulps and/or chemical pulps during newsprint manufacture, or other recycled paper applications such as tissue paper.
Flexible and Stretchable Paper-Based Structures for Electronic Applications
Published in Muhammad Mustafa Hussain, Nazek El-Atab, Handbook of Flexible and Stretchable Electronics, 2019
Tongfen Liang, Ramendra Kishor Pal, Xiyue Zou, Anna Root, Aaron D. Mazzeo
Second, porous structures stretch more easily than non-porous structures (Fan et al. 2017). As for paper, the number of interfiber bonds per fiber decreases with increasing porosity, thus resulting in increased strain-to-failure (Sehaqui et al. 2012). For example, tissue paper is ductile and soft, due to its open and sparse structure (Alava and Niskanen 2006). Similarly, porous nanocomposites made of NFC coated with hydroxyethyl cellulose (HEC, a water-soluble cellulose derivative) after supercritical drying are soft with a modulus of 0.8–1.3 GPa. Such nanocomposites with 44%–63% porosity show a nominal strain-to-failure as high as 55% (Figure 15.9a), which is greater than those with low porosity (13%–27%) by nearly 100% (Figure 15.9b). This increased ductility results from high porosity and limited interfibril bonding. Low friction facilitating fibril-fibril slippage of HEC-coated NFC may also contribute to an increase in ductility. Such stretchable nanocomposites also show high tensile strengths of 80–93 MPa. However, there is a tradeoff between the maximum strain at break and the strength of the material. Pre-stretching the nanocomposite can increase modulus, strength, and the yield strength substantially while decreasing its maximum strain at break (Figure 15.9c and d) (Sehaqui et al. 2012).
Life Cycle Assessment — Environmental Assessment of Products
Published in Sven Erik Jørgensen, A Systems Approach to the Environmental Analysis of Pollution Minimization, 2020
Michael Hauschild, Henrik Wenzel
A different allocation problem occurs in product systems that involve recycling loops, particularly the most common type of recycling, the recycling via open pool known for metals, paper, and glass in many countries. With this type of recycling the product is collected and its content of recyclable materials extracted into a pool that provides raw materials for products that may be unknown and generally belong to other product systems. An example is the use of paper-fibers from recycled office paper as a raw material for tissue paper or disposable diapers.
Comparison of Ontario’s roundwood and recycled fibre pulp and paper mills’ performance using data Envelopment analysis
Published in Journal of Management Analytics, 2021
The demand for the pulp is driven by demand for end products (for example, newsprint, kraft paper, linerboard, bleached paperboard, tissue paper, uncoated paper, and coated paper), which has varied significantly between different products. Some grades of paper, primarily newsprint and other print categories, have been experiencing falling demand due to the introduction of new forms of electronic communication, including e-books, e-readers and tablets. The corrugated packaging sector, on the other hand, has seen an increase in demand, as more people use online shopping, most of which is shipped in corrugated containers (AAC, 2015). Additionally, the decreased demand for certain paper grades has been mitigated by rising demand for others, including tissue, paperboard and specialty products, which primarily use recycled fibre. Packaging and industrial papers have been the bright spot in the Canadian paper industry, with demand fuelled by economic growth and rising consumer expenditures on food and general merchandise. However, based on the value of the Canadian shipments, the shipments of different pulp and paper product categories have stabilised in recent years, and the dramatic rate of decline in newsprint demand has slowed down (Statistics Canada, 2018). Although Ontario’s pulp exports to the U.S. have significantly declined from their peak in 2000, the province still enjoys a healthy pulp trade surplus totalling CAD 381.9 million (AAC, 2015). The capacity utilisation in the pulp and paper industry in Ontario has rebounded significantly, after witnessing number of mill closures and conversions.
Self-assembled supramolecular thermoreversible β-cyclodextrin/ethylene glycol injectable hydrogels with difunctional Pluronic®127 as controlled delivery depot of curcumin. Development, characterization and in vitro evaluation
Published in Journal of Biomaterials Science, Polymer Edition, 2018
Samiullah Khan, Muhammad Usman Minhas, Mahmood Ahmad, Mohammad Sohail
The swelling behavior of blank SSD injectable β-CD/EG-PF127 hydrogels was analyzed in DW, USP phosphate buffer solution of pH 7.4 (PBS, 5 mM) and pH 1.2 (0.1 M HCl buffer) at variable temperature programs in sealed containers. The swelling behavior of the thermoreversible physically cross-linked complexes was analyzed above their LCST (35 and 40 °C). Samples of the complex formed with a specific wet mass were dipped in beaker containing 50 ml of the swelling media and placed in a fan oven at the desired temperature. The beaker was sealed with a parafilm while in the oven to prevent evaporation. Periodically at specific intervals of time, the swelling media was removed by pouring the solution through a Buchner funnel. The sample surface was blotted with a soft tissue paper and the wet weight of the hydrogel sample was determined using analytical balance (Shimadzu, model ATY224). The samples were then submerged again in fresh swelling media and placed back in oven [45]. The % swelling of the samples was calculated using the following formula:
Fabrication and characterization of antibacterial and biodegradable facial tissue papers using bio-based raw materials: effect of gamma radiation
Published in Radiation Effects and Defects in Solids, 2018
Khandaker Umaiya, A. M. Sarwaruddin Chowdhury, Ruhul A. Khan, Md. Saifur Rahaman
In the primary stages of gamma irradiation, free radicals form due to the scission of molecular bonds. Incorporation of gamma radiation in carbohydrate films rupture the glucosidic bonds which leads to shortening of the polymer chain length by depolymerization as well as degradation of carbohydrates (cellulose, chitosan, alginates, cellobiose, lactose etc.) (27). Gamma radiation also supports the inactivation of pathogenic microorganisms, and hence can be used in biomedical product sterilization (28). In this study, antibacterial facial tissue paper films were fabricated and characterized using chitosan and cellulosic pulp. Then the effect of gamma radiation on the molecular interaction, as well as the mechanical and antibacterial properties were studied.