| 1. |
- Plackett, David, et al.
(author)
-
Physical Properties and Morphology of Films Prepared from Microfibrillated Cellulose and Microfibrillated Cellulose in Combination with Amylopectin
- 2010
-
In: Journal of Applied Polymer Science. - : Wiley. - 0021-8995 .- 1097-4628. ; 117:6, s. 3601-3609
-
Journal article (peer-reviewed)abstract
- Two types of microfibrillated cellulose (MFC) were prepared using either a sulfite pulp containing a high amount of hemicellulose (MFC 1) or a carboxymethylated dissolving pulp (MFC 2). MFC gels were then combined with amylopectin solutions to produce solvent-cast MFC-reinforced amylopectin films. Tensile testing revealed that MFC 2-reinforced films exhibited a more ductile behavior and that MFC 1-reinforced films had higher modulus of elasticity (E-modulus) at MFC loadings of 50 wt % or higher. Pure MFC films had relatively low oxygen permeability values when data were compared with those for a variety of other polymer films. MFC 1 and MFC 2 films had similar opacity but differences in appearance which were attributed to the presence of some larger fibers and nanofiber agglomerates in MFC 2. Field emission scanning electron microscopy (FE-SEM) and atomic force microscopy (AFM) were used to illustrate the morphology of MFC nanofibers in pure films and in an amylopectin matrix.
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
- Aldaeus, Fredrik, et al.
(author)
-
Towards a cellulose-based society : current market and consumer trends
- 2017
-
In: The 7th Nordic Wood Biorefinery Conference held in Stockholm, Sweden, 28-30 Mar. 2017. - Stockholm : RISE Bioekonomi. - 9789186018207 ; , s. 1-
-
Conference paper (other academic/artistic)abstract
- It has been proposed that the future of the forest industry will involve the traditional value chains combined with the needs and demands of a bio-based economy. A global consumer survey was undertaken, together with interviews and workshops with various representatives through the bio-economy. Sources also included in-depth literature studies and research reviews. Based on this input, several current trends have been identified that will affect the route towards a cellulose-based society. These trends describe the effects of urbanization, consumer behaviour, new business models, material recycling, open innovation and the necessity for early demonstration of new research. Four different but equally plausible scenarios have been identified describing the society and the role of cellulose in 2030, highlighting the role of the wood-based biorefinery.
|
|
| 5. |
- Aldaeus, Fredrik, et al.
(author)
-
Towards a cellulose-based society : current trends, future scenarios, and the role of the wood biorefinery
- 2016
-
In: Proceedings of the 14th European workshop on lignocellulosics and pulp. - 9791090188020 ; , s. 125-127
-
Conference paper (other academic/artistic)abstract
- There is a great need to maintain research for a future in which the traditional value chains of the forest industry are combined with the needs and demands of a bio-based economy. In such a future, the pulp mill biorefinery will be a crucial node. In order to map the transformation from a fossil-based society to a cellulose-based society, a global consumer survey has been made. In addition, interviews and workshops with various players throughout the bio-economy field have been accomplished. Several current trends that affect the road to a cellulose-based society have been identified. These trends are describing the effects of urbanization, consumer behaviour, new business models, material recycling, open innovation, and the need for early demonstration of new research. The trends have been combined with uncertainties into a number of plausible scenarios describing the society and the role of cellulose in the year 2030.
|
|
| 6. |
- Cho, Sung-Woo
(author)
-
Aging and heat-sealing properties of films based on wheat gluten
- 2007
-
Licentiate thesis (other academic/artistic)abstract
- Recently the research interest of the possibility of using wheat gluten (WG) as packaging material has greatly increased due to its combination of high gas barrier, attractive mechanical, film-forming and renewable properties. The source is also readily available and inexpensive on a worldwide basis. The glycerol-plasticized WG films cast from pH 4 and pH 11 solutions were investigated in order to understand the mechanisms behind the undesired aging. The film prepared from the pH 11 solution was mechanically more stable upon aging than the pH 4 film, which was initially very ductile but turning brittle with time. It was revealed that the protein structure of the pH 4 film was initially less polymerized/aggregated and the polymerization increased during storage but it did not reach the degree of aggregation of the pH 11 film, whereas deamidation was occurred and increased in the pH 11 film. During aging, the pH 4 film lost more mass than the pH 11 film mainly due to migration of glycerol but also due to some loss of volatile mass and the greater plasticizer loss of pH 4 film was presumably due to its initial lower degree of protein aggregation /polymerization. The glycerol migration of cast films exposed to a porous paper was further investigated with respect to pH of cast solution, glycerol content and film thickness since it was the main reason for deterioration of the properties. The opacity was also characterized. The glycerol migration was quantified using GC method in order to determine only glycerol content, but not other volatile substances. Glycerol content did not significantly change the opacity and pH 4 films showed good contact clarity because of less Maillard reaction. Glycerol was extensively migrating to the paper support and the migration seemed to be diffusion controlled. The heat sealability of WG films was investigated, using an impulse-hear sealer. It was observed that the WG films were readily sealable keeping up their integrity. The sealing temperature had a negligible effect on the lap-shear strength, but the peel strength increased with sealing temperature. The lap-shear strength increased with increasing mold temperature and the failure mode changed.
|
|
| 7. |
- Christiernin, M., et al.
(author)
-
The effects of xyloglucan on the properties of paper made from bleached kraft pulp
- 2003
-
In: Nordic Pulp & Paper Research Journal. - : Walter de Gruyter GmbH. - 0283-2631 .- 2000-0669. ; 18:2, s. 182-187
-
Journal article (peer-reviewed)abstract
- Xyloglucan was adsorbed onto bleached soft-wood kraft pulp followed by preparation and analysis of handsheets with respect to sheet formation as well as sheet mechanical and optical properties. Adsorption of xyloglucan was found to be slow. After more than 20 hrs adsorption, equilibrium had not been reached. The amount of xyloglucan adsorbed increased with beating, but neither the rate of adsorption nor the quantity adsorbed was significantly affected by temperature. Xyloglucan was found to be practically irreversibly adsorbed onto the fibres and the effects of xyloglucan on paper sheet properties were investigated after thorough washing of the pulp. The adsorption characteristics of xyloglucan confirm observations by other authors on other cellulose substrates. Tensile index values for handsheets formed with the xyloglucan-containing pulps were higher than those measured for control pulps with a comparable beating degree. The light scattering coefficient was, however, not affected by xyloglucan adsorption. Hence, the increase in tensile strength is attributed to an increased relative bond strength between the fibres. Tensile strength versus tear strength relationship was similar for pulps with and without xyloglucan, but water retention value and dewatering resistance were lower for the xyloglucan treated pulps than for the reference pulps at the same tensile strength. In addition, formation was improved for pulps with adsorbed xyloglucan. The conclusion is that xyloglucan is a promising wet end additive that decreases the necessity for beating of the pulp and improves the formation of paper.
|
|
| 8. |
- Ekevåg, Per, et al.
(author)
-
Addition of carboxymethylcellulose to the kraft cook
- 2004
-
In: Nordic Pulp & Paper Research Journal. - : Walter de Gruyter GmbH. - 0283-2631 .- 2000-0669. ; 19:2, s. 200-207
-
Journal article (peer-reviewed)abstract
- The physical attachment of carboxymethylcellulose (CMC) onto kraft pulps during cooking and the effects of subsequent bleaching in an OD(EOP)DD sequence were investigated. Two CMC grades with different molecular weights and different degrees of substitution (D.S.) were used, CMC Finnfix WRH and CMC Cekol DVG. The effect of the CMC was studied by measuring the increase in the total charge density as well as in the surface charge density. In this way, both the total amount of attached CMC and the amount of the CMC attached onto the surface of the fibres Could be determined. Hand-sheets were made to study the effects of CMC addition on the physical properties of the paper. Different amounts of CMC were added to find the optimum, which was determined to be 1% CMC on wood. The proportion of CMC attached at a level addition of 1% (on wood) was about 40%. It was, however, found that a large part of the CMC was degraded during the cook. Whereas high molecular weight CMC is attached onto the surface of fibres, the degraded CMC is attached to the interior of the cell wall, decreasing the efficiency of the CIVIC to enhance the joint strength between fibres. The tensile index increased significantly, approximately 10% after beating to 2000 PFI revolutions, when 1% CMC Finnfix WRH on wood was added. The CMC Cekol DVG grade showed the greatest increase in tensile index, approximately 12% at 2000 PFI revolutions. The results of the bleaching of a sample treated with CMC Finnfix WRH showed that a part of the effect of CMC remains after bleaching. Most of the reduction in the positive effect was due to a loss of CMC molecules from the fibre surface.
|
|
| 9. |
- Helander, Mikael, et al.
(author)
-
Parameters Affecting the Cross-flow Filtration of Dissolved LignoBoost Kraft Lignin
- 2015
-
In: Journal of wood chemistry and technology. - : Taylor & Francis Group. - 0277-3813 .- 1532-2319. ; 36:1, s. 1-8
-
Journal article (other academic/artistic)abstract
- In the kraft pulping process, the lignin-containing by-product kraft black liquor is currently combusted as an energy source. LignoBoost is a technique that extracts lignin from kraft black liquor, resulting in a lignin-lean black liquor, which is returned to the process, and an extracted kraft lignin. To facilitate the use of the extracted kraft lignin in high-value applications, it can be refined via fractionation to produce a more homogeneous starting raw material. Hence, the aim of this study is to investigate the behavior of dissolved softwood kraft lignin during cross-flow filtration. The effects of the lignin concentration, pH, and ionic strength on the fractionation of the dissolved lignin during cross-flow filtration are investigated. The results indicate that large amounts of low-molecular-weight kraft lignin can be produced from solutions having a low lignin concentration. Furthermore, the effects of pH and ionic strength on the fractionation of low-molecular-weight lignin are identified within the studied ranges.
|
|
| 10. |
- Henningsson, Susanne, 1977, et al.
(author)
-
Sex steroid-related genes and male-to-female transsexualism
- 2005
-
In: Psychoneuroendocrinology. - Oxford : Pergamon Press. - 0306-4530 .- 1873-3360. ; 59:5, s. 412-412
-
Journal article (peer-reviewed)abstract
- Transsexualism is characterised by Lifelong discomfort with the assigned sex and a strong identification with the opposite sex. The cause of transsexualism is unknown, but it has been suggested that an aberration in the early sexual differentiation of various brain structures may be involved. Animal experiments have revealed that the sexual differentiation of the brain is mainly due to an influence of testosterone, acting both via androgen receptors (ARs) and-after aromatase-catalyzed conversion to estradiol-via estrogen receptors (ERs). The present study examined the possible importance of three polymorphisms and their pairwise interactions for the development of male-to-female transsexualism: a CAG repeat sequence in the first exon of the AR gene, a tetra nucleotide repeat polymorphism in intron 4 of the aromatase gene, and a CA repeat polymorphism in intron 5 of the ER beta gene. Subjects were 29 Caucasian male-to-female transsexuals and 229 healthy mate controls. Transsexuals differed from controls with respect to the mean Length of the ER repeat polymorphism, but not with respect to the length of the other two studied polymorphisms. However, binary logistic regression analysis revealed significant partial effects for all three polymorphisms, as well as for the interaction between the AR and aromatase gene polymorphisms, on the risk of developing transsexualism. Given the small number of transsexuals in the study, the results should be interpreted with the utmost caution. Further study of the putative role of these and other sex steroid-related genes for the development of transsexualism may, however, be worthwhile.
|
|
