I strävan efter att minska textilindustrins omfattande miljöpåverkan utvecklas nya metoder för textilåtervinning. Idag återvinns bomullstyg av Renewcell på deras anläggning i Kristinehamn. Den återvunna produkten, Circulose®, är en dissolvingmassa som kan användas för att spinna nya viskosfibrer som man i sin tur kan använda för att göra nya kläder. Föreliggande arbete är en förstudie om möjligheten att optimera Renewcellls återvinningsprocess. Arbetet inkluderar en optimering av massaprocessen vilket resulterar i en mer effektiv process som minskar förbrukningen av processkemikalier. / To reduce the extensive environmental impact of the textile industry, new methods for textile recycling are being developed. Today, cotton-based fabric is recycled by Renewcell at their facility in Kristinehamn. The recycled product, Circulose®, is a dissolving pulp that can be used to spin new viscose fibers, which in turn can be used to make new clothes. The present work is a feasibility study on the possibility of optimizing Renewcell's recycling process. The work includes an optimization of the pulp process, which results in a more efficient process with a reduced consumption of process chemicals.

Abstract Introduction: The design of an exterior wall of timber construction where all forms ofplastic can be avoided is not something that is used in today's buildings in Sweden. Thepurpose of the study is to compare two exterior wall constructions where one exteriorwall is used in today's buildings and contains plastic foil. The other wall does notcontain plastic or steam brake.The aim of the report is to compare these two exterior wall constructions from amoisture perspective where the construction without plastic and steam brake is studiedto be able to verify whether it is possible to use this in today's buildings. The questionsto be studied are the following: - What is the basis for the material choices for wooden exterior wall construction? - How do the moisture conditions vary between the selected exterior wall of timberconstructions based on the actual experiment and the theoretical calculations? Method: The study consisted of a combination of qualitative and quantitative methodswhere several collection methods were used such as interviews, experiments andcalculations. The main topic in the study was moisture and with the help of the methodsprimary data were collected, as well as secondary data were collected through themethod literature study. Results: The study showed results how two different exterior wall of timberconstruction vary from each other based on the parameters relative humidity, steamcontent and temperature. The results are reported through tables and diagrams of howthe walls are affected in the worst possible cases regarding moisture surcharge. Analysis: The analysis links the question, the result, and the theoretical frameworktogether. The values presented in the results are linked to the framework wherescientific studies either support or do not support the results that have been producedduring the study. This finally answered the questions that the report was based on. Discussion: This part presents a discussion regarding the results which have beencollected in the study. This section also presents a method discussion containingarguments whether the methods worked or not.

Naturskyddsföreningen gav författarna uppgiften att undersöka förekommande viskosprocesser och alternativa regenereringsprocesser, detta för att identifiera hur hållbara de är ur ett miljöperspektiv och vilka processer som går att applicera på bambu. Detta för att se möjligheten att märka bambuviskos med Bra Miljöval och för att klargöra frekvent uppkommande frågor angående bambuviskos. Syftet är att se på de olika processernas kemiska innehåll samt vilka utsläpp de orsakar till luft och vatten. Ett delmål med rapporten är att den ska kunna användas som material vid vidareutveckling av kriterierna för Bra Miljöval Textil. Resultat som erhållits vid jämförelser av studerad litteratur är att de betydande faktorerna för miljöpåverkan från massaframställningen samt viskos- och lyocellprocessen beror av: använda kemikalier i processen, energianvändningen och vilken typ av energi, möjligheten till rening av utsläpp till luft och vatten samt återvinning av energi och kemikalier. Beroende på vilket råmaterial som används vid massaframställningen kan skillnader i markanvändning, användning av bekämpningsmedel och gödningsmedel samt upptagande av koldioxid skilja sig. Massa- och fiberframställning bör vara integrerade då energiförbrukning och mängd kemikalier kan minskas. Energin kan dessutom återvinnas till större utsträckning.Genom miljömärkningar från oberoende organisationer blir det lättare för konsumenter att göra miljömedvetna val och veta vad märkningarna står för. Sammanfattningsvis ska det påpekas att om regenererad bambu framställs som den görs idag är den ingen hållbar fiber, men sker framställningen i en integrerad process där kemikalier och energi återvinns samt rening av utsläpp till luft och vatten sker, kan bambuviskos bli en hållbar fiber för framtiden. The Swedish Society for Nature Conservation (SSNC) gave the authors the task to investigative present viscose processes and alternative regeneration processes to identify how sustainable they are from an environmental perspective, and examine which processes that can be applied to bamboo. This to see the possibility to label bamboo viscose with “Bra Miljöval” (Good Environmental Choice), which is the eco-label of SSNC, and to clarify the frequently emerging issues concerning bamboo viscose. The aim is to look at the various processes, their chemical content and the emissions they cause to air and water. Another objective of the report is that it can be used as material for further development of the criteria for “Bra Miljöval”.Results obtained when comparing the studied literature is that the significant factors of the environmental impact from the pulp production, the viscose and lyocell processes depends on: chemicals used in the process, energy and energy source, the possibility of purifying emissions to air and water and recycling of energy and chemicals. Depending on the raw materials used for pulp production, differences in land use, use of pesticides and fertilizers as well as absorption of carbon dioxide differ. Pulp and fibre production should be integrated to reduce energy consumption and the amount of chemicals used. The energy can also be recycled to a greater extent.Eco-labels from independent organizations will make it easier for consumers to make environmentally conscious choices and be aware of what the labels stand for.In conclusion, it should be noted that if the regenerated bamboo is produced as it is today, it is not a sustainable fibre. If the production is done through an integrated process in which chemicals and energy recovery and purification of air and water occurs, bamboo viscose can be a sustainable fibre for the future. / Program: Textilingenjörsutbildningen

<p> I viskosprocessens inledande merceriseringssteg behandlas cellulosa (dissolvingmassa) med natriumhydroxid (NaOH) varvid cellulosan omvandlas till alkalicellulosa. Därpå följer en sulfidering med koldisulfid (CS₂) som omvandlar alkalicellulosa till natriumxantogenat. Xantatet löses i en alkalisk lösning och en trögflytande vätska, viskos, bildas. Vid tillverkning av spinnviskos är sista steget i processen en surgörning där koldisulfiden spjälkas av och cellulosan återbildas i form av en tråd. Vid tillverkning av högviskös viskos (Freudenberg HP) sker regenereringen i basisk miljö men vid förhöjd temperatur (100°C), och återbildningen av cellulosa ger då en cellulosabaserad bädd. Genom att öka dissolvingmassans reaktivitet skulle förbrukningen av koldisulfid i sulfideringssteget kunna minskas. Med en ökad reaktivitet menas att fler hydroxylgrupper på cellulosan blir tillgängliga för vidare reaktioner med natriumhydroxid och koldisulfid. Detta skulle kunna möjliggöras med en enzymatisk förbehandling av massan.</p><p>Det första delmålet i projektet var att producera en viskos med hög viskositet i laboratorieskala. Projektets andra mål var att undersöka effekterna av en enzymatisk behandling, med enzymet Carezyme^®, på massans viskositet och reaktivitet.</p><p>En studie gjordes för att se hur olika tider i viskosprocessens andra steg, pressteget, påverkade cellulosahalten och luthalten för alkalicellulosa. Resultaten tydde på att en längre presstid gav en högre cellulosahalt upp till en viss tidpunkt. Vid 195 sekunder avklingade kurvan och effekten av en längre presstid minskade. Resultatet visade också på att mängden lut i alkalicellulosaprovet var relativt konstant och att luthalten inte påverkas nämnvärt av pressningen.</p><p>Vidare genomfördes försök kring viskosprocessens sulfideringssteg. Det fanns under projektets gång stora svårigheter i att uppnå samma höga nivå på gammatalet vid produktion av viskos i laborativ skala (52-58 %) som vid produktion i fabriksskala (68-70 %). Gammatalet är ett mått på hur väl koldisulfid har reagerat med cellulosa under sulfideringen. I ett försök att öka gammatalet satsades en större mängd koldisulfid, med förhoppningen att kunna kompensera för den relativt stora andel koldisulfid som befann sig i gasfas under reaktionen och som därmed inte var aktiv under sulfideringen. Den ökade mängden koldisulfid resulterade dock inte i en ökning av gammatalet. I ett annat försök tillsattes en svag natriumhydroxidlösning direkt till sulfideringskärlet vid avslutad reaktion, utan att någon effekt på gammatalet kunde påvisas. Det undersöktes även om ett ökat förhållande mellan luthalt och cellulosahalt i alkalicellulosan kunde ge någon positiv effekt på gammatalet. Denna förändring gav dock inget ökat gammatal.   </p><p>Dissolvingmassaprover behandlades med enzymet Carezyme^® för att kunna studera dess inverkan på massans reaktivitet och viskositet.  Resultaten visade på en tydlig nedgång i viskositet med högre koncentrationer av enzym. Reaktiviteten på den enzymbehandlade massan ökade i jämförelse med den obehandlade massan. Då viskos producerades med en enzymbehandlad massa kunde ingen effekt av enzymbehandlingen noteras, med avseende på gammatalet.</p><p> </p> / <p>In the first step of the conventional viscose process, called mercerization, cellulose (dissolving pulp) is treated with sodium hydroxide (NaOH) in which the cellulose is converted to alkali cellulose. Alkali cellulose is then treated with carbon disulphide (CS₂) to be converted into a sodium xanthate.  This xanthate is dissolved in an alkali solution and a viscous liquid, called viscose, is formed. The last step in the process is an acidification where the carbon disulphide is splinted off and the cellulose is regenerated in the shape of threads. When producing high viscosity viscose (Freudenberg HP) the regeneration takes place in an alkaline environment and the re-formation of cellulose gives a cellulosic based bed. By increasing the reactivity of the dissolving pulp the amount of carbon disulphide could be reduced, compared at the same degree of substitution. An increase in reactivity means that a larger amount of hydroxyl groups on the cellulose molecule are available to react with sodium hydroxide and carbon disulphide. This could be enabled by an enzymatic pretreatment of the pulp prior to the mercerization step.</p><p>The first aim of this project was to produce a high viscosity viscose in a laboratory scale, comparable to the viscose quality that is produced by Freudenberg HP. The second aim of the project was to investigate the effects of an enzymatic treatment (with the enzyme named Carezyme^®) on the viscosity and reactivity of the dissolving pulp. </p><p>A study was made to examine the influence of the time in the pressing step (after the mercerization) on the cellulose and sodium hydroxide content in the alkali cellulose. The results indicated a linear correlation between the cellulose content and the pressing time up to 195 seconds. At this point the correlation declined and the effects of a longer pressing time decreased. The results also showed that the amount of lye in the alkali cellulose sample was nearly constant and therefore not effected by the pressing time.</p><p>Tests were also carried out concerning the sulphidation step in the process. During the whole project there were difficulties in reaching the same gamma value of the viscose in a laboratory scale (52-58 %) compared to large-scale production (68 - 70%). The gamma value is a measurement of the degree of substitution for carbon disulphide on the cellulose backbone. In one attempt to enhance the gamma value the carbon disulphide charge was increased. The expectation was to compensate for the relatively high amounts of inactive carbon disulphide expected to be found in the gaseous phase in the reactor. However, this did not result in a higher gamma value. In another experiment a weak solution of sodium hydroxide was added directly to the sulphidation vessel after the reaction was completed, but no change in the gamma value was obtained. It was also investigated if an increased relation between the cellulose- and sodium hydroxide content in the alkali cellulose could affect the gamma value positively.  Unfortunately, this modification did not give an increased gamma value.</p><p>Samples of dissolving pulp were treated with the enzyme Carezyme^® to see its impact on viscosity and reactivity of the pulp. The results showed a distinct loss in viscosity with an increased enzyme concentration. The reactivity of the pulp increased compared to the untreated pulp. No effects of the enzymatic treatment could be seen on the final viscose when it was produced from an enzyme treated pulp.</p>

This thesis examines the formation of Polyelectrolyte Multilayers (PEM) on cellulose fibres as a new way of influencing the fibre surface and the adhesion between wood fibres. The aim of the study was to enhance the fundamental understanding of the adsorption mechanisms behind the formation of Polyelectrolyte Multilayers on cellulose fibres; to study how the properties of the layers can be influenced and to show how the properties of the layers influence the adhesion between the fibres and the strength of paper sheets made from the PEM treated fibres. Different polyelectrolyte systems are known to form PEMs with different properties, and in this work two different polymer systems were extensively studied: poly(dimethyldiallylammonium chloride) (PDADMAC) / poly(styrene sulphonate) (PSS), which are both strong polylectrolytes (i.e. are highly charged over a wide range of pH) and poly allylaminehydrochloride (PAH) /poly acrylic acid (PAA), which are both weak polyelectorlytes (i.e. sensitive to pH changes). PEMs were also formed from PAH/ poly(3,4-ethylenedioxythiophene):PSS (PEDOT:PSS), in order to form electrically conducting PEMs on fibres and PEM-like structures were formed from polyethylene oxide (PEO) and polyacrylic acid (PAA). In order to study the influence of the PEM on adhesion and paper strength, fibres were treated and used to form sheets which were physically tested according to determine the tensile index and strain at break. Both these systems were studied using different molecular mass fractions. High molecular mass PDADMAC/PSS (&gt;500k/1000k) had a significantly greater influence as a function of the number of layers than low molecular mass PDADMAC/PSS (30k/80k). In contrast, sheets made from high molecular mass PAH/PAA (70k/240k) showed a significantly lower increase in strength than sheets made from low molecular PAH/PAA investigated earlier. Both these systems had a greater influence on paper strength when the cationic polyelectrolyte was adsorbed in the outermost layer. The amount of polyelectrolytes adsorbed on the fibres was determined using polylectrolyte titration (PET) and destructive analytical methods. Adsorption to model surfaces of silicon oxide was studied before the adsorption on fibres, in order to understand the influence on PEM properties of parameters such as salt concentration and adsorption time. Adhesion studies of surfaces coated with PAH/PAA using AFM, showed an increase in adhesion as a function of the number of adsorbed layers. The adhesion was higher when PAH was adsorbed in the outermost layers. Individual fibres were also partly treated using a Dynamic Contact Angle analyser (DCA) and were studied with regard to their wettability. In general, the wettability was lower when the cationic polymer was outermost. The level of adhesion and paper strength are discussed in terms of rigidity and wettability and the PEMs demonstrating a large number of free chain ends, a large chain mobility and a low wettability was found to have the greatest influence to adhesion and paper strength. / QC 20100823

Mechanical pulping for producing pulps from softwood suitable for printing grade papers, like news, is a highly energy-intensive process consuming around 2000 kWh/t in electrical energy. Due to increasing energy costs and environmental issues there is a high demand for decreasing this energy consumption. The mechanical treatment of wet wood pieces in a refiner, in the mechanical pulp plant, is a complex mechanical loading. This is a process occurring between rotating discs at high speed and temperatures of 140 °C - 160 °C, where by means of shear and compression forces the fibres are separated and then made flexible, fibrillated and collapsed for good bonding ability. In this process also fines are created giving the optical properties of the paper. In mechanical pulping only a fraction of the applied energy is used for the structural changes of the wood material. Thus fundamental studies of the loading modes of wood under refining conditions and in particular under combined shear and compression loading are desired to gain more information regarding the possibility of affecting the mechanical pulping in an energy efficient way. The possibilities to study the behaviour of wood under a combined shear and compression load were in this thesis investigated using two methods: the Iosipescu shear test and the Arcan shear test. In both apparatus different combinations of shear and compression load were achieved by different rotations of the shear test device itself. Measurements with the Iosipescu device on a medium density fibreboard showed good agreement between experimental results and numerical simulations. Finite element analysis on wood showed, however, that with the use of a homogeneous material in the model the level of strain reached would be ten times smaller than experimentally measured. This fact is probably due to the honeycomb structure of the wood cells that allows for different local deformations that could not be represented by a continuous material model. Thus to study the deformations on the fibre level of wood an experimental equipment that uses smaller samples was needed. With a modified Arcan shear device such deformations under combined shear and compression load and in pure compression were possible showing different deformation patterns. During pure compression the cell walls bend in a characteristic “S” shape, independently of the shape of the fibre cells and their cell wall thickness. Under combined shear and compression, however, mainly the corners of the fibre cells deform giving a “brick” shape to the cells. In a second deformation performed in compression, the fibre cells follow the same deformation pattern as given by the first deformation type whether in compression or in combined shear and compression. The interpretation is that permanent defects in the cells themselves are introduced already in the first load cycle of the wood samples. The energy used under the different loading conditions showed that the first deformation required the largest amount of energy, for all loading conditions. The deformation in compression required larger amounts of energy than the deformation in combined loads. For subsequent deformations less energy was needed for compression if a combined load had preceded it. Due to the fact that less energy is needed to start to deform wood in combined load than under compression load, the application of a combined load as a first cycle may thus be a way to permanently deform fibres using less energy. To investigate the critical parameters determining the permanent deformation of cells, a finite element model of a network of twelve cells was developed. Special care was given to the material properties to study how the variation of the fibril angle in the different layers affects the deformation pattern of the wood fibres under the different loading conditions. The model shows that whether modelled as homogeneous linear isotropic material or as an orthotropic material defined for every layer of the cells wall, no difference in the deformation of the network of the fibres was achieved. It is probable that the deformation type is more determined by the geometry of the fibres themselves than by their material properties / QC 20101005

<p>Polysaccharides constitute an important source of raw materials for the packaging industry today. Polysaccharides have good natural barrier properties which are necessary for packaging films. Cellulose is the forerunner among renewable polymers for such applications. Hemicelluloses represent a new interesting breed of barrier materials. We have chosen to work with the hemicellulose O-acetyl-galactoglucomannan (AcGGM). The high water solubility of this particular hemicellulose extracted from process waters is both an advantage and a limiting factor. However, through the right modification, the water sensitivity of AcGGM can be regulated.</p><p>This thesis presents four ways to modify AcGGM: (i) benzylation, (ii) plasma surface treatment followed by styrene addition, (iii) vapor-phase (VP) surface grafting with styrene, and (iv) lamination of an unmodified film with a benzylated material. The most important methods of analysis of the films produced include contact angle measurement, dynamic mechanical analysis under moisture scan, and oxygen gas permeability measurement.</p><p>It was found that unmodified AcGGM films have low oxygen permeability at intermediate relative humidity (50 % RH) and good dynamic mechanical properties over a wider humidity range. Films of benzylated material (BnGGM) exhibited a decrease in oxygen permeability at lower humidity but showed better tolerance to higher humidities and indicated better dynamic mechanical behavior than AcGGM films. Lamination proved to be the most promising technique of modification, combining the good gas barrier properties of AcGGM films with the moisture-insensitivity of the BnGGM films.</p>

A pilot project in 2010, conducted at CBI, showed the capacity for pulp, micro fibrilars from the forest industry to act as Viscosity Modifying Agent (VMA) in concrete. This project was, however, too limited to find answers for optimal use of this kind of material. The forest industry company Stora Enso wants to find out if their pulp can be used in concrete in order to somehow improve its properties. Two micro fibrilar suspensions have been tested. The tested fibrils are in two sizes, the finer material named MFC1 has undergone more homogenization than the course material named MFC2. The fibrils have been evaluated in regard to how the fibrils react with mortars in both its fresh and hardened state. Tests have been conducted on the use of concrete equivalent mortars with a maximum aggregates size of 4 mm. Two water-cement-ratios have been used in the tests, 0.45 and 0.60. Three different fibril dosages have been tested, 1, 2 and 3 kg/m³. The results of these trials of cellulose fibrils has been evaluated in respect of rheology, compressive strength, flexural strength, cracking, shrinkage, water capillary porosity, anti-wash out resistance (underwater concrete) and as a possible surface coverage. The results from the trials, conducted in this report, show that an increased dosage of fibrils leads to an increased plastic viscosity. The fibrils appear to have no effect on the flexural- and compressive strength, and no effect on the shrinkage of the test specimens. According to our results it is not advisable to use the fibrils for the purpose of acting as an agent for anti-washout resistance, or as a surface coverage.   The work have been performed at Swedish Cement and Concrete Research Institute, CBI, in Stockholm in the spring of 2011. CBI is an institution whose mission is to create, apply and disseminate knowledge in the concrete and rock area. / Ett tidigare pilotprojekt har under 2010 utförts på CBI, och där undersöktes möjligheten för cellulosafibrer från skogsindustrin att fungera som Viscosity Modifying Agent (VMA) i betong. Utrymmet i detta projekt var dock för begränsat för att finna svar för optimal användning av denna typ av material. Nu vill skogsindustriföretaget Stora Enso ta reda på om massa från deras träprodukter kan användas i betong, för att på något sätt förbättra dess egenskaper. Vi har därför provat suspensioner innehållande två olika fraktioner av cellulosafibriller. De testade fibrerna finns i två storlekar, det finare materialet heter MFC1 och har genomgått med homogenisering än det grövre materialer som heter MFC2. Dessa två typer har tillsats i bruk och utvärderats i hur de reagerar i både brukets färska och dess hårdnade tillstånd. Testerna har genomförts på bruk med en maximal ballaststorlek på 4 mm. Två vct-nivåer har använts i försöken, 0,45 och 0,60. Tre olika fibrilldoser har prövats, nämligen 1, 2 och 3 kg/m³ fibriller. Resultaten från dessa försök av cellulosafibriller har utvärderats med avseende på reologi, tryckhållfasthet, böjhållfasthet, sprickbildning, kapillaritet, krympning, anti-urvaskning och som möjlig ytbetäckning.   De tester som har genomförts visar att med ökad dos fibriller ökar den plastiska viskositeten. Fibrillerna visade sig inte ha någon effekt på böj- eller tryckhållfasheten, samt ingen effekt på krympning av provkropparna. Testerna visar att fibrillerna inte heller agerar med någon possitiv effekt som anti-urvaskningsmedel, eller som ett täckande ytskikt.   Försöken har genomförts vid CBI Betonginstitutet i Stockholm mellan 21 mars och 8 juli år 2011.CBI är en institution vars uppdrag är att skapa, tillämpa och sprida kunskap inom betong och bergområdet.

Ett nytt sätt att aktivera cellulosa för kemisk modifiering med hjälp av en miljövänlig process har utvecklats innan starten av detta projekt. Två versionen av den nyskapade betain-baserade jonvätskan, BBIL har syntetiserats, en som använder mesylat som motjon, M-BBIL och en som använder acetat, A-BBIL. Innan yt-initierad Ringöppningspolymerisation (SI-ROP) kan göras på den aktiverade cellulosan är det av intresse att undersöka hur jonvätskorna kommer påverka polymerisationen.  Det katalytiska beteendet hos både M-BBIL och A-BBIL testades på två olika polymerisationsreaktioner. Först testades ROP av ε-CL. Resultaten visade att ingen av jonvätskorna kunde visa någon samkatalytisk förmåga när de användes tillsammans med katalysatorerna MSA och DPP. När A-BBIL användes på egen hand ansågs den vara ineffektiv då termisk nedbrytning hämmade polymerisation vid temperaturer över 85oC. M-BBIL kunde dock uppnå bra kinetik då den användes vid 160oC. Den andra reaktionen som testades var coROP av ftalsyraanhydrid-cyklohexenoxid (PACHO) samt ftalsyraanhydrid-limonenoxid (PALO). Båda sampolymerisationer lyckades polymerisera med hjälp av M-BBIL, med endast mindre mängder av homopolymerisation av epoxiden under rätt förhållanden. Reaktionen visade sig dock vara mycket känslig för vatten och mer arbete krävs för att optimera reaktionen och nå högre molekylvikter. Tester för att försöka ympa PACHO polymerer på cellulosa som först hade aktiverats och sedan modifierats för att ha ftalsyraanhydrid på ytan visade sig också vara mycket känsliga för vatten. En lyckad ympning kunde dock uppnås genom att utföra reaktionen i ett delvist torkat, hydrofobt lösningsmedel. / A new way of activating cellulose for chemical modification using green processing conditions has been developed before the start of this thesis. Two versions of the novel betaine-based ionic liquid, BBIL has been synthesised, one using mesylate as a counter-ion, M-BBIL and one using acetate, A-BBIL. Before surface initiated-Ring Opening Polymerisation (SI-ROP) onto the activated cellulose can proceed, it is of interest to investigate the effects that the ionic liquids will have on the polymerization behaviour. The catalytic behaviour of both M-BBIL and A-BBIL were tested on two different polymerisation reactions. Firstly, ROP of ε-CL was tested. The results showed that neither ionic liquid could show any co-catalytic behaviour when used in combination with the catalysts MSA and DPP. When used on their own, A-BBIL was concluded to be ineffective since thermal degradation inhibited polymerisation at temperatures above 85oC. M-BBIL could however achieve good kinetics when used at 160oC. The second reaction that was tested was the coROP of phthahlic anhydridecyclohexene oxide (PACHO) and phthalic anhydride-limonene oxide (PALO). Both copolymerisations could successfully be polymerised using M-BBIL, with only minor amounts of homopolymerisation of the epoxide if the right conditions were used. The reactions were however shown to be highly sensitive to water and more optimization is needed to reach higher molecular weights. Tests of trying to graft the PACHO polymers onto cellulose that had first been activated and then modified with phthalic anhydride moieties was also shown to be highly sensitive to water. Successful grafting could however be achieved by performing reaction in partially dried hydrophobic solvents.

With the growing impact of climate change on both political decisions and how companies develop their products, it is increasingly important to find environmentally friendly alternatives to fossil-based materials. One of the more interesting materials in this respect is cellulose, which is the world's most naturally occurring polymer and can be used in a variety of applications. One way to modify the fibers and to change their properties is to use a method called Layer-by-Layer (LbL) treatment where two polymers of opposite charge are alternately adsorbed to the fiber surface. Another possibility is to oxidize the cellulose in the fibers to obtain a higher charge. This means that the fibers can adsorb a higher amount of cationic additives and that the fibers swell more which means that they are plasticized and can create stronger joints between the fiber surfaces in the dry state, which results in stronger dry fiber networks. However, wood-based fibers are small and inhomogeneous, both chemically and morphologically, which means that it is necessary to use model systems to be able to clarify, in detail, how treated and untreated surfaces interact with each other at a molecular level. One model system that can be used to investigate how cellulose fibers are affected by coating using the LbL method is to use spherical beads made from regenerated cellulose. In the present work, these beads were treated with polyallylamine hydrochloride (PAH) and hylauronic acid (HA) as well as with PAH and alginate (Alg) before being allowed to dry together and then subjected to tensile testing to clarify the adhesion between the surfaces. The beads were treated with five and ten bi-layers of these polymers, respectively, and then dried together on an AKD-coated surface, to avoid adhesion to the underlying surface, to examine the adhesion between the beads. The adhesion increased when treated with LbL and became higher upon adsorption of multiple layers of polyelectrolytes and the Alg / PAH system showed the greatest increase. Ten-layer samples of Alg / PAH were also tested after a solution of calcium chloride was added during drying, resulting in poorer adhesion between the beads. / Med klimatfrågans växande inverkan på både politiska beslut och hur företagen utvecklar sina produkter så läggs det allt större vikt vid att hitta miljövänliga alternativ till fossilbaserade material. Ett av de mer intressanta materialen är cellulosa vilket är världens mest naturligt förekommande polymer och som kan användas i en rad olika tillämpningar. Ett sätt att modifiera fibrerna och att ändra deras egenskaper är att använda sig av en metod som kalls Layer-by-layer (LbL) behandling där två polymerer mot motsatt laddning växelvis adsorberas till fiberytan. En annan möjlighet är att oxidera cellulosan i fibrerna så att de erhåller de en högre laddning. Detta innebär dels att fibrerna kan adsorbera en högre mängd katjoniska tillsatskemikalier samt att fibrerna sväller mera vilket innebär att de plasticeras och kan skapa starkare fogar mellan fiberytorna i torrt tillstånd vilket resulterar i starkare torra fibernätverk. Vedbaserade fibrer är dock små och inhomogena såväl kemiskt som morfologiskt vilket innebär att det är nödvändigt att använda modellsystem för att kunna klarlägga, i detalj, hur behandlade och icke behandlade ytor växelverkar med varandra på en molekylär nivå. Ett modellsystem som kan användas för att undersöka hur cellulosafibrer påverkas av att beläggas med hjälp av LbL metoden är att använda sig av sfäriska kulor tillverkade från regenererad cellulosa. I föreliggande arbete behandlades dessa kulor med polyallylaminhydroklorid (PAH) och hylauronsyra (HA) samt med PAH och alginat (Alg) innan de tilläts torka ihop och därefter utsattes för dragprovning för att klarlägga adhesionen mellan ytorna. Kulorna behandlades med fem respektive tio bilager av dessa polymerer och torkades sedan ihop på en AKD-belagd yta, för att undvika adhesion till den underliggande ytan, för att undersöka adhesionen mellan kulorna. Adhesionen ökade när de behandlades med LbL och blev högre vid adsorption av flera lager polyelektrolyter och systemet med Alg/PAH resulterade i den största ökningen. Prover med tio lager av Alg/PAH testades även efter att en lösning av kalciumklorid tillsattes under torkningen vilket resulterade i en sämre adhesion mellan kulorna.