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[pt] Corrosão é um fenômeno natural que afeta basicamente todo tipo de material, consome bilhões de dólares anualmente em todo o mundo e pode ter resultados catastróficos. Revestimentos são a técnica de prevenção de corrosão mais utilizada de todas. Nesse sentido, resinas epóxi são amplamente utilizadas em todos os setores da indústria. Apesar de serem polímeros de alta performance, resinas epóxi apresentam problemas, como a necessidade do uso de endurecedores normalmente tóxicos e longos tempos de cura. Benzoxazinas são uma classe emergente de monômeros termofixos de alta performance e auto-cura. Enquanto monômeros mono- e bifuncionais são tipicamente explorados, benzoxazinas de funcionalidade mais alta e sintetizados em procedimento sem solvente e purificados por solventes mais seguros, são um caminho mais desejável em direção à síntese de PBZ para aplicações de alta performance. Nesse trabalho nós descrevemos uma abordagem sustentável para a síntese de benzoxazina trifuncional a partir de melamina, fenol e paraformaldeído. A estrutura química do monômero sintetizado foi confirmada por análises espectroscópicas, enquanto o processo de polimerização foi monitorado por análise calorimétrica. O monômero de benzoxazina foi, então, copolimerizado com uma resina epóxi bifuncional comercial. Nós investimgamos o efeito sinergístico no aumento das propriedades térmicas por meio de DSC e TGA. Resultados revelaram temperatura de transição vítrea de até 268 Graus C. Alta estabilidade térmica também foi obtida, com início de degradação próximo a 400 Graus C e rendimento residual de 22 wt (porcentagem) a 800 Graus C. Posteriormente, o copolímero foi combinado com sílica para produzir revestimentos anti-corrosão. Resultados revelaram superfícies superhidrofóbicas com ótimas resistência a risco e adesão ao substrato de aço. Teste eletroquímico provou alta efetividade dos revestimentos como barreira anti-corrosão, com performance aumentada pela incorporação de sílica. / [en] Corrosion is a natural phenomenon that affects virtually every material, consumes billions of dollars annually worldwide and may result in catastrophic events. Coating is the most utilized technique to prevent corrosion. In this sense, epoxies are widely applied in all sectors of industry. Despite being high performance polymers, epoxies present issues, such as the use of toxic crosslinkers and long curing time. Benzoxazines are an emerging class of high performance self-curing thermosets. While typical monomers are based on mono- and difunctional derivatives, higher functional benzoxazines, prepared without using solvents, but purified with nontoxic solvents, are more desirable towards a greener synthesis of PBZ for high performance applications. Herein, we describe an environment-friendly approach to synthesizing a trifunctional benzoxazine from melamine, phenol, and paraformaldehyde. The chemical structure of the synthesized benzoxazine was confirmed by spectroscopic analyses, while the polymerization was monitored by thermal analysis. The synthesized benzoxazine monomer is, then, copolymerized with a commercial difunctional epoxy resin. We investigate the synergistic effect on improved thermal properties using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Results showed that a glass transition temperature of up to 268 Degrees C was obtained. A higher thermal stability was also achieved with an onset degradation of nearly 400 Degrees C and char yield of 22 wt (percentage) at 800 degrees C. Later, the copolymer was combined with silica to produce anticorrosion coatings. Results revealed superhydrophobic surfaces with great scratch resistance and adhesion to steel substrate. Electrochemical test proved high effectiveness of the coatings as anti-corrosion barrier, with increasing performance with the incorporation of silica.

This thesis focuses on employing a new patterning technique called block copolymer lithography to transfer the nano-porous pattern from the polymer template to the underlying oxide thin film. Nano-porous block copolymer films are produced by spin-coating polymer solution on wafers followed by annealing, UV exposure and development processes. Reactive-ion etching is then used to etch the oxide films based on the pattern of polymer template and the polymer is then removed. The obtained oxide microstructure is characterized by SEM, showing a nanomesh of microdomains with the same hole size and density as the initial block copolymer layer. The advantages of block copolymer lithography include uniform nanopatterning, cost efficiency and simple processing. The nano-porous oxide thin films could be used as hard mask for nanopatterning in microelectronics and for energy storage applications. / Denna avhandling fokuserar på användningen av en ny mönstringsteknik som kallas block-sampolymerlitografi som används för att överföra nano-porösa mönster från polymermaller till en underliggande oxidtunnfilm. Nano-porösa blocksampolymerfilmer framställs genom spinbeläggningspolymerlösning på skivor följt av glödgning, UV-exponering och utvecklingsprocesser. Reaktionjon etsning används sedan för att etsa oxidfilmerna baserat på mönstret av polymermaller och därefter blir polymeren avlägsnad. Den erhållna oxidmikrostrukturen karakteriseras av SEM, som visar en nanomesh av mikrodomäner med samma hålstorlek och densitet som det ursprungliga blocksampolymerskiktet. Fördelarna med block-sampolymerlitografi innefattar likformig nanomönstring, kostnadseffektivitet och enkel bearbetning. De nanoporösa oxidtunnfilmerna kan användas som en hard mask för nanomönstring i mikroelektronik och för energilagringsapplikationer.

Supramolecular polymers represent a family of polymeric materials that are held together with dynamic, noncovalent interactions. In contrast to conventional functional polymers that usually have high melt-viscosity due to their covalent nature and chain entanglement, supramolecular polymers combine excellent physical properties with low melt-viscosity, allowing for less energy-intensive processability and recyclability. Dynamic bonding with multiple binding sites, such as multiple hydrogen bonding or multiple ionic bonding, exhibits much stronger binding strength compared to the counterparts containing only a single binding site, thereby allowing for enhanced mechanical integrity to the polymers and facilitate self-assembly. This dissertation focuses on the design of novel supramolecular polymers building from the doubly-charged or quadruple hydrogen bonding (QHB) scaffolds utilizing chain-growth polymerization or step-growth polymerization, as well as elucidate the structure-property-morphology relationships of the polymers. A 2-step nucleophilic substitution reaction afforded a series of 1,4-diazabicyclo[2.2.2]octane (DABCO)-based styrenic monomers with two pairs of charged groups. An optimized 2-step reversible-addition-fragmentation chain-transfer (RAFT) polymerization synthesized ABA triblock thermoplastic elastomers (TPEs) with a low Tg poly (n-butyl acrylate) central block and a high Tg external charged blocks. Strong ionic interactions between doubly-charged units drove molecular self-assembly to form densely packed, hierarchical microstructures, which contributed to a robust, crosslinked physical network that allows the polymer to retain thermomechanical integrity until degradation. High-resolution single-crystal X-ray diffraction (SCXRD) coupled with powder X-ray diffraction (PXRD) further disclosed a detailed 3-D structural information of molecular arrangement and ion distribution within the charged phase through comparing DABCO-salt monomer single-crystal structure and the corresponding homopolymer XRD pattern. It was found that the physical properties of the DABCO-salt copolymers not only relied on their charge content and architectures but also dependent on their electrostatically-bonded counterions. The size and structure of the counterion determined the strength of dipole-dipole interaction, which significantly impact on thermal property, (thermo)mechanical performance, water affinity, and microstructure. A cytosine-functionalized monomer, cytosine acrylate (CyA), allowed the synthesis of acrylic ABA triblock TPEs with pendant nucleobase moieties in the external blocks and a low Tg central polymer matrix through RAFT polymerization. Post-functionalization of cytosine (Cyt) bidentate hydrogen bonding sites with alkyl isocyanate, allowed the formation of ureido-cytosine (UCyt) groups in the external block that were readily dimerized through QHB interactions. The UCyt units in the external block enhanced mechanical strength and induced stronger phase-separation of the block copolymers compared to the corresponding Cyt-containing TPE analogs. Facile conventional free-radical polymerization using CyA and subsequent post-functionalization enabled accessibility to random copolymers containing pendant UCyt QHB moieties in the soft polymer matrix. The synergy of the flexible polymer matrix and the dynamic character of QHB groups contributed to the ultra-high elasticity of the polymer and rapid self-healing properties. QHB interactions enabled efficient mechanical recovery upon deformation by facilitating elastic chain retraction to regenerate the original physical network. Finally, one-pot step-growth polymerization through chain extending a novel bis-Cyt monomer and a commercially available polyether diamine using a di-isocyanate extender afforded segmented polyurea series for extrusion additive manufacturing. The molecular design of the polyureas featured soft segments containing flexible polyether chain and a relatively weak urea hydrogen bonding sites in the soft segment and rigid UCyt hydrogen bonding groups in the hard segment. The reversible characteristics of QHB enabled low viscosity at the processing temperature while providing mechanical integrity after processing and reinforced bonding between the interlayers, which contributed to the remarkable strength, elasticity, toughness, and interlayer adhesion of the printed parts. / Doctor of Philosophy / This dissertation focuses on designing supramolecular thermoplastic elastomers containing strong noncovalent interactions, i.e., quadruple hydrogen bonds or double ionic bonds. Inspired from noncovalent interactions in our mother nature, a series of bio-inspired monomers functionalized with nucleobase or ionic units were synthesized through scalable reactions with minimal purification steps. Polymerization of the functional monomers through step-growth or chain-growth polymerization techniques affords a variety of supramolecular thermoplastic elastomers with well-defined structures and architectures. These thermoplastic elastomers comprise soft and hard constituents; the former contains low glass transition polymer chains that provide elasticity while the latter contains strong noncovalent units to impart mechanical strength. Varying the soft/hard component ratios enables polymers with tunable physical properties to address different needs. Systematic characterizations of these supramolecular polymers revealed their distinct properties from the polymers containing the covalent or weak noncovalent interactions and facilitate molecular-level understanding of the polymers. Generally, incorporating strong noncovalent interactions increases the temperature for polymer segmental motion and extends thermomechanical plateau windows. Additionally, the strong association strength of those non-covalent interactions promotes microphase separation and self-assembly, contributing to a high degree of structural ordering of the polymers. Moreover, the dynamic characteristics of the noncovalent interactions offer the polymers with reversible properties, which not only enables melt-processability and recyclability of the polymer but also contributes to a series of smart properties, including self-healing, shape-memory, and recoverability. Thus, the molecular design using supramolecular chemistry provides promising avenues to developing functional materials with enhanced mechanical properties, processability, and stimuli-responsiveness for emerging applications.

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För att motverka att innehållet i en behållare läcker ut krävs det att förslutningen är tät. För att förhindra läckage används någon form av tätning. På kapsyler i plast integreras ofta tätande element direkt i kapsylen i form av läppar eller kanter som pressar mot flaskan.Studien berör den inbyggda tätningen på en ”push-on”-kapsyl i Polypropencopolymer. Kapsylen tillverkas av Emballator Växjöplast AB och kallas DLM (dropless medicine) då den i de flesta fall monteras på glas- eller plastflaska som innehåller medicin. Kapsylens underdel pressas på flaskan permanent och den tvådelade kapsylen fungerar genom att en separat överdel skruvas på underdelen.Studien innehåller produktutvecklingssteg för att ta fram en uppdaterad konstruktion som ska klara av de problem som flaskans profil medför. Studien är upplagd som en DRM-studie och försöker svara på vad som påverkar tätningsförmågan hos en kapsyl och hur de tätande elementen kan konstrueras för att neutralisera flaskans form. Problemen uppstår främst när kapsylen är monterad på glasflaskan och roteras, då flaskan i vissa fall har en något oval profil. Det är när flaskan roteras som tätningen inte anpassar sig tillräckligt fort för att bli tät igen. Genom arbetets gång har man insett att i stället för att forma tätningen så att den följer behållarens form fortare, och riskera plastisk deformation på grund av relaxation hos materialet, väljer man att placera ytterligare en tätning på toppen. Ytan på toppen av flaskan utnyttjas, eftersom det är en ledig yta på både kapsyl och flaska,för att tätningarna ska komplettera varandra. Det görs för att kunna ha kvar den nuvarande tätningen och endast addera en topptätning som är mindre känslig för ovalitet hos flaskan. Studiens resultat bör ses som underlag för framtagning av prototyper och testning, då det inte går att garantera konstruktionens duglighet utan fortsatt testning / To prevent the contents of a container from leakage the closure of the container mustbe sealed. Some kind of seal is used to prevent leakage. The sealing part of plastic caps is usually integrated in the design of the cap in form of lips or edges that areputting pressure against the bottle.The study refers to the integrated seal on a “push-on” cap that is made of Polypropylene copolymer. The cap is manufactured by Emballator Växjöplast AB and is called DLM (dropless medicine) since it is mounted to a glass or plastic bottle containing medicine in most cases. The bottom part of the cap is pressed onto the bottle permanently and the two-part design works through a separate top part that is screwed onto the bottom part.The study contains product development steps to create an updated design that manages the problems caused by the profile of the bottle. The study is laid out as a DRM-study that is trying to answer what is affecting a cap´s ability to seal and how the sealing elements can be designed to neutralize the shape of the bottle. The problems are appearing mostly when the cap is mounted to the glass bottle and is rotated, since the bottle in some cases has an oval profile. It is when the bottle is rotated that the seal is not adapting fast enough to become sealed again.Through the process of the study, it has been realized that it is better to place a second seal on top of the bottle instead of designing a seal that follows the shape of the container. This is done to reduce the risk of plastic deformation due to relaxation of the material. The surface at the top of the bottle is utilized, since it is an unoccupied space at both the cap and the bottle, to have the seals complete each other. This is done to be able to keep the current seal and just add a top-seal that is less sensitive for ovality of the bottle. The results of the study should be seen as a basis for production of prototypes and testing since it not possible to guarantee the capability of the design without continued testing.

<p>The phase behavior of AB diblock copolymers mixed with C homopolymers (AB/C), in which A and C are capable of forming hydrogen-bonds, is examined using self-consistent field theory. The study focuses on the modeling of hydrogen-bonding in polymers. Specifically, we examine two models for the formation of hydrogen-bonds between polymer chains. The first commonly used model assumes a large attractive interaction parameter between the A/C monomers. This model reproduces correct phase transition sequences as compared with experiments, but it fails to correctly describe the change of lamellar spacing induced by the addition of the C homopolymers. The second model is based on the fact that hydrogen-bonding leads to A/C complexation. We show that the interpolymer complexation model predicts correctly the order-order phase transition sequences and the decrease of lamellar spacing for strong hydrogen-bonding. Our analysis demonstrates that hydrogen-bonding of polymers should be modeled by interpolymer complexation.</p> / Master of Science (MSc)