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Syftet med detta examensarbete var att utveckla ett hållbart ersättningsmaterial till akrylnitrilbutadienstyren plast (ABS), genom att applicera principerna för grön kemi och teknik. ABS är en icke-nedbrytbar plast som till exempel används i slagtåliga produkter för hyttinteriörer. Att utveckla ett nytt material baserat på en kravspecifikation med en specifik produkt i åtanke är av stor betydelse då en initial teoretiska utvärdering kan ge resultat som driver ytterligare innovation och säkerställer en god överensstämmelse med förväntningarna på produkten. Baserat på den genomförda litteraturutvärderingen och kravspecifikationen för produkten valdes polylaktid (PLA) som matrismaterial och blandades med nanofibrer av lignocellulosa (LCNF) och naturgummi (NR), där maleinsyraanhydrid (MA) användes som kompatibilisator. Denna modifieringsstrategi syftade till att förbättra PLAs styrka och minska dess sprödhet. Flera olika parametrar undersöktes, vilka inkluderar olika torkningsmetoder för LCNF:en och olika metoder för MA tillsats före bearbetningen av blandningen. Termisk analys av blandningarna visade att tillsatsen av LCHF och NR inte påverkar nedbrytningstemperaturen för PLA-matrisen i någon större utsträckning, men att kristalliniteten påverkades av dem och de olika behandlingsmetoderna. Styvheten hos de PLA-baserade materialen var likvärdig ABS, medan elasticitet var generellt likvärdig PLA och där tillsatsen av naturgummi förbättrade materialens deformationskapacitet. SEM bilder indikerade att de tre komponenterna var kompatibiliserade, då fibrösa strukturer och sammanflätade nätverk av LCNF och NR i PLA-matrisen kunde observeras. SEM bilderna visade också att NR agglomererade då stora agglomerat och porösa strukturer uppstod, vilket understryker vikten av att optimera framtida blandningsstrategier. En livscykelbedömning (LCA), enligt en vagga-till-graven metod, förväntas visa lägre koldioxidutsläpp för det föreslagna alternativet jämfört med ABS tack vare tillämpn, This thesis aims to develop sustainable replacement for Acrylonitrile Butadiene Styrene (ABS) in high-impact applications within construction equipment’s Cab interior. Adhering to the principles of Green Chemistry and Engineering, the study focused on developing and accessing an environmentally friendly substitute for ABS, a commonly used non-biodegradable plastic. Investigating novel materials with a tailored requirements list is vital in materials science and engineering. Theoretical approaches can yield results which drive further innovation, ensuring comprehensive alignment with application expectations through a holistic approach to address critical factors. Following this guideline, the chosen alternative was Polylactide (PLA), fortified with a blend of lignocellulose nanofibers (LCNFs) and natural rubber (NR) at a 10 wt.% concentration, with the addition of Maleic Anhydride (MA) as a compatibilizer. This modification strategy aimed to enhance PLA's strength and reduce its brittleness. The investigation encompassed various parameters, including different LCNF drying methods and variations in additive treatment before melt-mixing with PLA. The outcomes from thermal analysis indicated that the inclusion of reinforcements does not significantly affect the degradation temperature of the PLA matrix. Crystallinity, on the other hand, was found to be influenced by the presence of lignocellulose reinforcements and natural rubber, with intriguing nuances emerging from the interplay of these components and different treatment methods. PLA-based alternatives performed similarly to low grade ABS and had similar stiffness levels. In terms of elasticity, most materials behaved similarly to neat PLA, but the addition of natural rubber enhanced their deformation capacity. Successful compatibilization between lignocellulose reinforcements, natural rubber, and PLA was assumed from the observed fibrous structures and interwoven networks within the PLA matrix. Additionally, the p

The paradigm shift from traditional petroleum-based non-recyclable thermosets to biobased repeatedly recyclable materials is required to move toward circular bioeconomy. Here, two mechanically and chemically recyclable extended vanillin-derived epoxy thermosets are successfully fabricated by introduction of Schiff-base/imine covalent dynamic bonds. Thermoset 1 (T1) is based on linear monomer 1 (M1) with two alcohol end groups and one imine bond, while thermoset 2 (T2) is based on branched monomer 2 (M2) with three alcohol end-groups and three imine-groups. Thermosets are obtained by reaction of monomer 1 (M1) and monomer 2 (M2) with trimethylolpropane triglycidyl ether. The structure of the monomers and thermosets is confirmed by nuclear magnetic resonance and Fourier transform infrared spectroscopic techniques. Both thermosets exhibit good thermal and mechanical properties and they are stable in common organic solvents. Furthermore, they can be thermally reprocessed through compression molding with good recovery of the mechanical properties. Last but not least, the fabricated thermosets can be rapidly and completely chemically recycled to water-soluble aldehydes and amines by imine hydrolysis at room temperature in 0.1 m HCl solution. This is promising for development of future materials with multiple circularity by different routes., QC 20230628

Syftet med denna studie var att utveckla en biokomposit med både fett-och vattenbarriär. Material med dessa egenskaper innehåller idag ofta PFAS-molekyler (per- och polyfluorerade alkylsubstanser). Det är av stor betydelse att byta ut dessa mot ett biobaserat alternativ då de är giftiga och ackumuleras i naturen. Biokompositen utvecklades genom att kombinera icke-trä pappersmassa (75%) och trä pappersmassa (25%) som matris. Därefter tillsattes olika biobaserade additiv i våtände för att påverka materialets egenskaper. Proverna testades på deras dragstyrka, vattenavvisning och fettavvisning. Den stora utmaningen var att lyckas med fettavisningen. 1% Polysackarid 1 tillsammans med 0.5% sizing komponent var det provet som gav bäst resultat. För att utvärdera denna metod gjordes en jämförelse med ytbehandling. Det gjordes genom att stryka på några av de tidigare använda additiven på ytan av matrisen. Ytbehandlingen visade sig ha en större påverkan på fettavvisningen men med liknande eller sämre påverkan på vattenavvisningen. Nackdelen med denna metod är att den kräver ett flertal extra steg i produktionen., The aim of this thesis work was to develop a pulp-based biocomposite material with good water and grease barrier properties. It is important to achieve such properties to able to replace PFAS (poly- and perfluoroalkyl substances) molecules due to their toxicity and accumulation. Different types of pulp were evaluated as the matrix and the optimal matrix was based on non-wood pulp (75%) with wood pulp 1 (25%). This was also combined with several different additives in the wet-end. The samples were tested for their tensile strength, water resistance and grease resistance. The biggest challenge was to achieve adequate grease resistance. 1% Polysaccharide 1 together with 0.5% sizing agent was one of the better samples. It was clear the additives affected each other when used in combination with each other which indicates that wet end chemistry is complex. For a comparison, some additives were also tested as coatings. This technique resulted in better grease resistance but requires several extra steps in the production.

The evaluation of poly(limonene carbonate)s (PLCs), derived from orange oils and carbon dioxide, as UV-curable (powder) coating binders is described. PLCs with moderate molecular weight were prepared by copolymerization of limonene oxide with CO2 and a subsequent molecular weight reduction step by transcarbonation with 1,10-decanediol (1,10-DCD). These PLCs were cured with a trifunctional thiol monomer in the presence of a photoinitiator via thiol-ene chemistry to form poly(thioether-co-carbonate) networks. The UV curing of the resins following solvent casting was studied at 130 degrees C using ATR-FTIR, revealing a fast curing and a quick thiol-ene network (TEN) formation, realized by the addition reactions of thiol groups of the curing agent onto pendant isopropenyl groups of PLC. An ene addition enhanced by thiol-ene crosslinking was also observed, known as a 'cage effect', which was discovered for the first time in a UV-curable thiol-ene system. The efficient TEN formation was also evidenced by the high sol fractions in those UV-cured samples and their dynamic mechanical thermal analysis (DMTA). The DMTA results of these TENs showed high Tgs (up to 125.9 degrees C) and a wide range of thermomechanical properties, including rubbery moduli from 4.4-27.5 MPa. The UV-cured powder coating employing PLCs as binders showed outstanding properties such as high transparency, good acetone resistance, high pencil hardness (H-2 H) and high Konig hardness (174-199 s), suggesting their potential as very promising biobased alternatives to conventional powder coating resins., QC 20210301

På grund av ökad användning av plast har biobaserade polymerer som förpackningsmaterialfått stor uppmärksamhet de senaste åren på grund av miljöhänsyn. Flera proteinmaterial, t.ex.vetegluten har varit i fokus för betydande forskning kring ny biobaserad plast och resultatenär lovande. Det idag stora intresset för biobaserad och miljövänlig plast beror påväxthuseffekten från konventionell petroleumbaserad plast. Ett proteinmaterial från undersöktes här för dess plastmaterialegenskaper. Proteinrenheten varca. 65%. Filmerna skapades genom att först mala proteinflingorna till ett fint pulver ochblanda det med glycerol. Glycerolhalten var 30 %. Därefter varmpressades materialet. För atttesta plasten användes flera tekniker och metoder. TGA, DSC, FT-IR, WVTR, OTR ochdragprovning. I allmänhet var materialet relativt svagt. Liksom de flesta proteinplaster hadedet också dåliga vattenbarriäregenskaper, men hade relativt goda syrebarriäregenskaper. Sammanfattningsvis är det ett material som kan ha en ljus framtid eftersom det är tillverkat avbiomassa istället för petroleum, vilket innebär att det är mer miljövänligt. Med modifieringkan det bli en bra plast för flera ändamål., Due to increase use of plastics, bio-based polymers as packaging materials have garneredmuch attention in recent years due to environmental concerns. Several protein materials, e.g.wheat gluten, have been in focus for significant research towards new biobased plastics andresults are promising. Bio-based and environmentally friendly plastics gather much interestand attention today due to the green-house generating effects of conventional petroleum-basedplastics. A protein material was investigated here for its plastic material properties. The protein puritywas ca. 65 %. The films were created by first grinding the protein flakes to a fine powder andmixing it with glycerol. The glycerol content was 30 %. The material was subsequently hotpressed.To test the plastic, multiple techniques and methods were used. TGA, DSC, FT-IR, WVTR,OTR and tensile testing. In general, the material was relatively weak. As most protein plasticsit had also poor water barrier properties, however it had relatively good oxygen-barrierproperties. In conclusion it is a material that could have a bright future as it is made from biomass insteadof petroleum, which means that it is more environmentally friendly. With modification andimprovement, it can be a good plastic for several applications in future.

This review deals with the evolution of bio-based packaging and the emergence of various nanotechnologies for primary food packaging. The end-of life issues of packaging is discussed and particularly the environmental problems associated with microplastics in the marine environment, which serve as a vector for the assimilation of persistent organic pollutants in the oceans and are transported into the food chain via marine and wild life. The use of biodegradable polymers has been a primary route to alleviate these environmental problems, but for various reasons the market has not developed at a sufficient pace that would cope with the mentioned environmental issues. Currently, the biodegradable plastics only constitute a small fraction of the fossil-based plastic market. Fossil-based plastics are, however, indispensable for food safety and minimization of food waste, and are not only cheap, but has generally more suitable mechanical and barrier properties compared to biodegradable polymers. More recently, various nanotechnologies such as the use of nanoclays, nanocellulose, layer-by-layer technologies and polyelectrolyte complexes have emerged as viable technologies to make oxygen and water vapor barriers suitable for food packaging. These technological developments are highlighted as well as issues like biodegradation, recycling, legislation issues and safety and toxicity of these nanotechnologies., QC 20210224

A facile one-pot spray-drying process was developed for fabrication and in-situ crosslinking of chitosan microspheres to improve the adsorption capacity by microscopic design. A fully biobased nature was achieved by utilizing genipin (GP) as a crosslinking agent and chitosan derived nano-graphene oxide (nGO) as a property tuner. The produced chitosan microspheres were further proven as powerful adsorbents for common wastewater contaminants such as anionic dyes and pharmaceutical contaminants, here modelled by methyl orange (MO) and diclofenac sodium (DCF). By regulating the amount of GP and nGO, as well as by controlling the process parameters including the spraydrying inlet temperature and post-heat treatment, the surface morphology, size, zeta potential and adsorption efficiency of the microspheres could be tuned accordingly. The adsorption efficiency for MO and DCF reached 98.9 and 100 %, respectively. The microspheres retained high DCF adsorption efficiency after six adsorption and desorption cycles and the recyclability was improved by incorporated nGO. The fabricated microspheres, thus, have great potential as reusable and eco-friendly adsorbents., QC 20190410

A sustainable strategy to fabricate chitosan-based composite hydrogels with tunable properties and controllable adsorption capacity of trace pharmaceuticals was demonstrated. Two biobased modifiers were utilized to tune the properties, nano-graphene oxide (nGO) derived from chitosan via microwave-assisted carbonization and oxidation, and genipin as the crosslinking agent. An increase in genipin content facilitated an increase in the degree of crosslinking as shown by improved storage modulus and decreased swelling ratio. Increasing nGO content changed the surface microtopography of the hydrogel which correlated with the surface wettability. nGO also catalyzed the genipin-crosslinking reaction. The hydrogel was further shown to be an effective adsorbent for a common anti-inflammatory drug, diclofenac sodium (DCF), with the removal efficiency ranging from 91 to 100% after 48 h. DCF adsorption efficiency could be tuned through simple alteration of nGO and genipin concentration, which provides promising potential for this environmental-friendly adsorbent in removal of DCF from pharmaceutical waste water., QC 20180530

1,3-Dioxolan-4-one (DOX) chemistry was explored for production of "one-pot" biobased polyester thermosets. DOX monomer was first functionalized by naturally occurring eugenol to introduce a structural element, which could induce cross-linking reaction through cationic polymerization of the double bond. The feasibility of polymerizing DOX monomers bearing bulky side groups was proven by model phenol-substituted DOX monomer (PhDOX). Once the reaction was shown to be effective, the same protocol was applied to eugenol-substituted monomer (EuDOX). A brief screening of the optimal catalyst concentration was performed, to obtain a highly cross-linked product. The synthesized thermoset showed good thermal resistance and high mechanical strength probably due to the rich aromatic content. The obtained thermoset was further subjected to microwave-assisted hydrothermal degradation test, which demonstrated complete recyclability to water or methanol soluble products. NMR and matrix-assisted laser desorption/ionization-mass spectroscopy analyses of the obtained degradation products unveiled the structure of the thermoset, strongly indicating that the polymerization of eugenol-functionalized DOX monomer resulted in polylactide-like chains connected with aromatic aliphatic segments resulting from the reaction of the eugenol double bonds. The presence of free hydroxyl and carboxyl groups sheds light on the mechanism behind the observed shape-memory and self-healing properties., QC 20190108

A green strategy for fabrication of biobased reduced nanographene oxide (r-nGO) was developed. Cellulose derived nanographene oxide (nGO) type carbon nanodots were reduced by microwave assisted hydrothermal treatment with superheated water alone or in the presence of caffeic acid (CA), a green reducing agent. The carbon nanodots, r-nGO and r-nGO-CA, obtained through the two different reaction routes without or with the added reducing agent, were characterized by multiple analytical techniques including FTIR, XPS, Raman, XRD, TGA, TEM, AFM, UV-vis, and DLS to confirm and evaluate the efficiency of the reduction reactions. A significant decrease in oxygen content accompanied by increased number of sp2 hybridized functional groups was confirmed in both cases. The synergistic effect of superheated water and reducing agent resulted in the highest C/O ratio and thermal stability, which also supported a more efficient reduction. Interesting optical properties were detected by fluorescence spectroscopy where nGO, r-nGO, and r-nGO-CA all displayed excitation dependent fluorescence behavior. r-nGO-CA and its precursor nGO were evaluated toward osteoblastic cells MG-63 and exhibited nontoxic behavior up to 200 μg mL-1, which gives promise for utilization in biomedical applications., QC 20210802

The performance of different esterification catalysts was studied for the use in synthesis of renewable polyesters from dimethyl itaconate (DMI), dimethyl succinate (DMS) and 1,4-butanediol (BD). Itaconic acid and derivatives such as DMI are interesting monomers because of their multiple functionalities and previous work has shown great potential. However, the multiple functionalities also pose challenges to avoid side reactions such as thermally initiated, premature, radical crosslinking and/or isomerization of the 1,1-disubstituted unsaturation. Additionally, the two carboxylic acids have inherently different reactivity. One key factor to control reactions with IA is to understand the performance of different catalysts. In this study, six esterification catalysts were investigated; immobilized Candida antarctica lipase B (CalB), titanium(IV)butoxide (Ti(OBu)4), p-toluenesulfonic acid (pTSA), sulfuric acid (H2SO4), 1,8-diazabicycloundec-7-ene (DBU), and 1,5,7-triazabicyclodec-5-ene (TBD). CalB and Ti(OBu)4 were selected for further characterization with appreciable differences in catalytic activity and selectivity towards DMI. CalB was the most effective catalysts and was applied at 60 °C while Ti(OBu)4 required 160 °C for a reasonable reaction rate. CalB was selective towards DMS and the non-conjugated side of DMI, resulting in polyesters with itaconate-residues mainly located at the chain ends, while Ti(OBu)4 showed low selectivity, resulting in polyesters with more randomly incorporated itaconate units. Thermal analysis of the polyesters showed that the CalB-catalyzed polyesters were semi-crystalline, whereas the Ti(OBu)4-catalyzed polyesters were amorphous, affirming the difference in monomer sequence. The polyester resins were crosslinked by UV-initiated free radical polymerization and the material properties were evaluated and showed that the crosslinked materials had similar material properties. The films from the polyester resins catalyzed by CalB were furt, QC 20180601

The present work describes the synthesis and characterization of fully biobased soft polymer networks for pressure sensitive adhesives applications. The incorporation of different sugars into fatty-acid-based monomers, made it possible to tailor the viscoelastic properties of the materials. Lipase catalysis allowed to afford monomers with varying hydroxyl content and epoxy-functionalities. Step-growth polymerization catalyzed by DBU resulted in soft-polyester networks through combination of the monomers with a biobased diacid. Rheological and adhesion studies were performed to elucidate the different viscoelastic and adhesive properties of the materials as a function of their composition., QC 20170510