Differences in swelling of chemical pulp fibers and cotton fibers – Effect of the supramolecular structure

Palme, Anna; Aldaeus, Fredrik; Larsson, Tomas; Hasani, Merima; Theliander, Hans; Brelid, Harald

doi:10.15376/biores.14.3.5698-5715

Cited by 3 publications

(2 citation statements)

References 38 publications

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“…In spherical contour plots, the correlations between the important variables are insignificant. The ellipsoidal contour revealed a variety of relationships between the variables (Chen et al , 2016; Palme et al , 2019).…”

Section: Resultsmentioning

confidence: 99%

Effects of precipitated and ground calcium carbonate coating on mechanical properties of fluting paper

Çiçekler

Üzüm

Çopurkuyu

2023

PRT

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Purpose The purpose of this study is to investigate the effects of a pigment coating on the mechanical properties of fluting paper. Design/methodology/approach Two different calcium carbonate pigments were used in the preparation of the coated color, precipitated calcium carbonate (PCC) and ground calcium carbonate (GCC). Fluting paper produced by recycling waste paper was used as base paper. The effects of PCC and GCC pigments on mechanical properties were compared. Ring crush test (RCT), corrugating medium test (CMT), corrugating crush test (CCT), tensile and burst strength tests were applied to the coated papers, and the results were compared to the mechanical properties of base paper. Findings The tensile and burst indices of the coated papers were found to be higher than base papers about 13.9% and 6.05%, respectively. While the coating process positively affected the RCT and CCT values, it did not show a significant impact on the CMT values. GCC, one of the pigments used in coating colors, had a more effective effect on the mechanical properties of fluting papers compared to PCC. Originality/value These results suggest that coating of fluting papers has a positive effect on mechanical properties and the use of GCC as a pigment is more effective than PCC.

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Section: Resultsmentioning

confidence: 99%

Effects of precipitated and ground calcium carbonate coating on mechanical properties of fluting paper

Çiçekler

Üzüm

Çopurkuyu

2023

PRT

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“…More recently, (Chen et al 2020) studied the dissolution mechanism of several cellulosic fibers by tracking the evolution of the fiber diameter under optical microscopy. Using a similar approach (Mäkelä et al 2018) explored the influence of the dissolving pulp in cupriethylene diamine and Palme and coworkers compared pulp and cotton fibers (Palme et al 2019). Alternatively, we have explored the impact of microwave (MW) heating over the cellulose dissolution under different conditions using technique based on UV-VIS spectroscopy (Sánchez et al 2020).…”

Section: Introductionmentioning

confidence: 99%

Dissolution kinetics of cellulose in ionic solvents by polarized light microscopy

2023

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Aiming to increase the scarce information available on the kinetics of cellulose dissolution, we have applied an image-assisted technique based on the luminance evolution as cellulose dissolves to study this process under different experimental conditions. This protocol was validated via direct determination of the cellulose dissolved. In all cases datapoints were linearly fitted assuming a pseudo-zero order reaction which facilitates the comparison between datasets. To study the solvent effect we have used three ionic liquids with large basicity and found significantly different rates of dissolution, from faster to slower: [C$$_2$$ 2 C$$_1$$ 1 Im][OAc]>[C$$_1$$ 1 C$$_1$$ 1 Im][DMP]>[C$$_2$$ 2 C$$_1$$ 1 Im][DEP]. Solvatochromic parameters and viscosity of the solvent media were determined and the latter was identified as a key factor slowing the process as it reduces ionic mobility. The weight of viscosity was estimated by removing the viscosity effect with a tuned solvent media doped with DMSO. Activation energy was 70% lower at constant viscosity. On the substrate side, particle size is the main factor affecting the dissolution rate. All samples were milled to homogenise the starting material and minimise the distortions caused by the size distribution. After, dissolution of three cellulose substrates under the same experimental conditions was analysed. Dissolution of natural fibers took twice as long as dissolving pulp which dissolves slower than lyocell fibers. This trend correlates with the roughness of the samples obtained by optical perfilometry which is consistent with the dissolution mechanism proposed in the literature. Graphical abstract

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Process modifications to obtain a prehydrolysis kraft dissolving pulp with low limiting pulp viscosity

Brännvall

Walter²

2020

Nordic Pulp &Amp; Paper Research Journal

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Cellulose can be directly dissolved in cold alkali without derivatization. However, this requires low cellulose molecular weight, i. e. low pulp viscosity, preferably below 300 mL g−1. This can be achieved by for example acid or enzymatic hydrolysis of the dissolving pulp. However, it would be beneficial to manufacture pulp with sufficiently low viscosity without an additional treatment stage prior to dissolution. Unit processes in pulping can be operated in such a way as to reduce the molecular weight of cellulose. The approach of the study was to modify the conditions in unit pulping processes in order to obtain a low pulp viscosity of fully bleached prehydrolysis kraft pulp. A high charge of alkali in the oxygen delignification reduced the cellulose molecular weight significantly. Increased temperature, 120 °C compared to 98 °C, had also a significant effect on viscosity. By performing peroxide bleaching at acidic pH, the viscosity could be sufficiently reduced even when oxygen delignification was performed at lower temperature. However, for high brightness, a chlorine dioxide stage is needed.

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Differences in swelling of chemical pulp fibers and cotton fibers – Effect of the supramolecular structure

Cited by 3 publications

References 38 publications

Effects of precipitated and ground calcium carbonate coating on mechanical properties of fluting paper

Effects of precipitated and ground calcium carbonate coating on mechanical properties of fluting paper

Dissolution kinetics of cellulose in ionic solvents by polarized light microscopy

Process modifications to obtain a prehydrolysis kraft dissolving pulp with low limiting pulp viscosity

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