Les bandes magnétiques sont des assemblages multicouches utilisant des réseaux polyuréthanes. Ces matériaux organiques sont utilisés en tant que revêtement protecteur contenant des pigments ou en tant que liant assurant la cohésion des charges magnétiques utilisées pour le codage d’informations. Parmi les défauts, dont l’apparition nécessite une meilleure compréhension des réactions chimiques mises en jeu lors de l’élaboration de ces assemblages, le développement d’une adhésion excessive entre les bandes et des plaques de PVC pouvant conduire à une dégradation par arrachement a été ciblé pour cette étude.L’influence des conditions de réactions (atmosphère, température et rapports molaires alcool/isocyanate) sur la cinétique de réticulation de systèmes polyuréthanes modèles a permis de quantifier les espèces réactives résiduelles à l’issue de la formation du réseau et de mettre en évidence l’implication des fonctions isocyanate dans des réactions secondaires, et une inhibition de leur réactivité lorsque les réactions ne sont pas conduites en conditions inertes. La présence d’eau dans le milieu réactionnel a été reliée l’implication des fonctions isocyanate dans la formation de liaisons urée. Enfin, la réalisation d’assemblages modèles n’a pas permis de reproduire les arrachements mais l’étude d’assemblages fournis par l’industriel suggère que le procédé utilisé pour la mise en forme de la couche de protection soit la cause de ce défaut. / Magnetic tapes are multilayer assemblies using polyurethane networks. These organic materials are used as a protective coating containing pigments or as a binder ensuring the cohesion of the magnetic charges used for the information coding. Among the defects, the appearance of which requires a better chemical reactions involved in these assemblies development understanding, an excessive adhesion development between the strips and PVC plates which can lead to degradation by tearing been targeted for this study.The reaction conditions influence (atmosphere, temperature and alcohol / isocyanate molar ratios) on the crosslinking kinetics of model polyurethane systems made it possible to quantify the residual reactive species at the network formation end and to prove the isocyanate functions involvement in side reactions, and their reactivity inhibition when the reactions are not conducted under inert conditions. The water presence in the reaction environment was related to the isocyanate functions involvement in the urea bonds formation. Finally, the model assemblies realization did not make it possible to reproduce the stripping but the assemblies provided by the industrialist study suggests that the process used for the protective layer shaping is the defect cause.

Phenol Formaldehyde (PF) and polymeric isocyanate (pMDI) are the two main types of adhesives used in the production of structural wood-based composites. Much is unknown about various aspects of adhesion between these two types of resins and wood. The present research describes the development of techniques which will permit an enhanced understanding of 1.) the extent of cure of PF within a wood based composite, 2.) the scale of molecular level interactions between PF and pMDI and wood, 3.) mechanical performance and durability of wood-adhesive bonds. Correlations were established between conventional methods of characterization of neat PF (thermomechanical analysis, swelling studies) and measurements made using 13C CP/MAS NMR. These correlations were then utilized to characterize PF cured in the presence of wood. The use of 13C labeled PF allowed estimates of relative degrees of resin conversion to be made. The use of 13C and deuterium labeled PF allowed qualitative estimates of resin molecular rigidity to be made. The scale of molecular level interactions between PF and pMDI and wood was probed using NMR relaxation experiments. Evidence was shown to suggest the formation of an interpenetrating polymer network (IPN) morphology existing at both types of wood-resin interphases. The formation of the IPN morphology was strongly influenced by resin molecular weight, cure temperature and the presence of solvent. A new test geometry for the evaluation of the fracture toughness of wood-adhesive bonds was developed. Consistent and reliable results were obtained. It was found that low molecular weight PF possessed enhanced durability over high molecular weight. / Ph. D.

Bio-inspired monomers functionalized with nucleobase or ionic group allowed synthesis of supramolecular polymers using free radical polymerization and controlled radical polymerization techniques. Comprehensive investigations for the structure-property-morphology relationships of these supramolecular polymers elucidated the effect of noncovalent interactions on polymer physical properties and self-assembly behaviors. Reverse addition-fragmentation chain transfer (RAFT) polymerization afforded acrylic ABC and ABA triblock copolymers with nucleobase-functionalized external blocks and a low-Tg central block. The hard-soft-hard triblock polymer architecture drove microphase-separation into a physically crosslinked hard phase in a low Tg matrix. Hydrogen bonding in the hard phase enhanced the mechanical strength and maintained processability of microphase-separated copolymers for thermoplastics and elastomers. A thermodynamically favored one-to-one stoichiometry of adenine and thymine yielded the optimal thermomechanical performance. Intermolecular hydrogen bonding of two thymine units and one adenine unit allowed the formation of base triplets and directed self-assembly of ABC triblock copolymers into remarkably well-defined lamellae with long-range ordering. Acetyl protected cytosine and guanine-containing random copolymers exhibited tunable cohesive strength and peel strength as pressure sensitive adhesives. Post-functionalization converted unprotected cytosine pendent groups in acrylic random copolymers to ureido-cytosine units that formed quadruple self-hydrogen bonding. Ureido-cytosine containing random copolymers self-assembled into nano-fibrillar hard domains in a soft acrylic matrix, and exhibited enhanced cohesive strength, wide service temperature window, and low moisture uptake as soft adhesives. A library of styrenic DABCO salt-containing monomers allowed the synthesis of random ionomers with two quaternized nitrogen cations on each ionic pendant group. Thermomechanical, morphological, and rheological analyses revealed that doubly-charged DABCO salts formed stronger ionic association and promoted more well-defined microphase-separation compared to singly-charged analogs with the same charge density. Bulkier counterions led to enhanced thermal stability, increased phase-mixing, and reduced water uptake for DABCO salt-containing copolymers, while alkyl substituent lengths only significantly affected water uptake of DABCO salt-containing copolymers. Step growth polymerization of plant oil-based AB monomer and diamines enabled the synthesis of unprecedented isocyanate-free poly(amide hydroxyurethane)s, the first examples of film-forming, linear isocyanate-free polyurethanes with mechanical integrity and processability. Successful electrospinning of segmented PAHUs afforded randomly orientated, semicrystalline fibers that formed stretchable, free-standing fiber mats with superior cell adhesion and biocompatibility. / Ph. D.

Water-based resol phenol formaldehyde, PF, and organic polymeric methylenebis(phenylisocyanate), pMDI, are the two primary choices for the manufacture of exterior grade wood-based composites. This work addresses simple physical blends of pMDI dispersed in PF as a possible hybrid wood adhesive. Part one of this study examined the morphology of hybrid blends prepared using commercially available PF and pMDI. It was found that the blend components rapidly reacted such that the dispersed pMDI droplets became encased in a polymeric membrane. The phase separation created during liquid/liquid blending appeared to have been preserved in the cured, solid-state. However, substantial interdiffusion and copolymerization between blend components also appeared to have occurred according to measured cure rates, dynamic mechanical analysis, and atomic force microscopy. In the second part of this study a series of PF resins was synthesized employing the so-called "split-cook" method, and by using a range of formaldehyde/phenol and NaOH/phenol mole ratios. These neat PF resins were subjected to the following analyses: 1) steady-state flow viscometry, 2) free formaldehyde titration, 3) non-volatile solids determination, 4) size exclusion chromatography, 5) quantitative solution-state ¹³C nuclear magnetic resonance, NMR, 6) differential scanning calorimetry, 7) parallel-plate oscillatory cure rheology, and 8) dielectric spectroscopy. The neat PF analytical results were unremarkable with one exception; NMR revealed that the formaldehyde/phenol mole ratio in one resin substantially differed from the target mole ratio. The neat PF resins were subsequently used to prepare of series of PF/pMDI blends in a ratio of 75 parts PF solids to 25 parts pMDI solids. The resulting PF/pMDI blends were subjected to the following analyses: 1) differential scanning calorimetry, 2) parallel-plate oscillatory cure rheology, and 3) dielectric spectroscopy. Similar to what was inferred in part one of this study, both differential scanning calorimetry (DSC) and oscillation cure rheology demonstrated that cure of the PF continuous phase was substantially altered and accelerated by pMDI. However within actual wood bondlines, dielectric analysis detected little variation in cure speed between any of the formulations, both hybrid and neat PF. Furthermore, the modulated DSC curing experiments detected some latent reactivity in the hybrid system, both during initial isothermal curing and subsequent thermal scanning. The latent reactivity may suggest that a significant diffusion barrier existed between blend components, preventing complete reaction of hybrid blends even after thermal scanning up to 200 °C. Part three of this work examined the bonded wood mode-I fracture performance of hybrid resins as a function of the resol formaldehyde/phenol ratio and also the alkali content. A moderate increase in unweathered fracture toughness was observed for hybrid formulations relative to neat PF. Following accelerated weathering, the durability of the hybrid blends was promising: weathered hybrid toughness was equivalent to that of weathered neat PF. While the resol F/P ratio and alkali content both influenced hybrid fracture toughness, statistical modeling revealed interaction between these variables that complicated result interpretation: the influence of hybrid alkali content depended heavily on each formulation's specific F/P ratio, and vice versa. / Master of Science

Facile monomer synthesis provided routes towards novel step-growth polymers for emerging applications. Adjustment of reaction conditions enabled green synthetic strategies, and promising scalability studies offered impetus for industrial funding. Engineering thermoplastics, such as linear polyetherimides (PEIs), had carefully targeted molecular weights for analysis of the effect of molecular weight and regiochemistry on the thermomechanical and rheological properties of PEIs. The design of linear, high performance PEIs comprising 3,3'- and 4,4'-bisphenol-A dianhydride (bis-DA) and m-phenylene diamine (mPD) provided an opportunity to elucidate the influence of dianhydride regiochemistry on thermomechanical and rheological properties. This unique pair of regioisomers allowed the tuning of the thermal and rheological properties for high glass transition temperature polyimides for engineering applications. The selection of the dianhydride regioisomer influenced the weight loss profile, entanglement molecular weight, glass transition temperature (Tg), tensile strain-at-break, zero-shear melt viscosity, average hole-size free volume, and the plateau modulus prior to viscous flow during dynamic mechanical analysis (DMA). The 3,3'-PEI composition interestingly exhibited a ~20 °C higher Tg than the corresponding 4,4'-PEI analog. Moreover, melt rheological analysis revealed a two-fold increase in Me for 3,3'-PEI, which pointed to the origin of the differences in mechanical and rheological properties as a function of PEI backbone geometry. The frequently studied 4,4'-PEI exhibited exceptional thermal, mechanical, and rheological properties, yet the 3,3'-PEI regioisomer lacked significant study in the industrial and academic sectors due to its 'inferior' properties, namely poor mechanical properties. Introduction of long-chain branching (LCB) into PEIs provided a unique comparison between a commercially relevant PEI (Ultem® 1000) and a regioisomer infrequently found in the literature. Thermal stability remained consistent for each regioisomer, and Tgs for the 3,3'- and 4,4'-LCB-PEIs agreed well with prior literature. Rheological analysis demonstrated typical shear thinning and low-shear viscosity trends for LCB systems. The targeted molecular weights for the 3,3'-LCB-PEIs were well below the Me cutoff for "high molecular weight," and for this reason the rheological properties demonstrated inconsistent trends. Further study of PEIs led to the incorporation of ionic endgroups. These provided physical crosslinks, which enhanced mechanical and rheological properties of branched PEIs compared to their non-ionic analogs. The Tgs decreased with an increase in branching concentration for the phenyl-terminated PEI, while it remained unchanged for the ionically-endcapped PEIs. The divalent salts demonstrated higher mechanical strength and melt viscosities compared to the monovalent salt and the non-ionic PEIs. Interestingly, the zinc-endcapped PEI series exhibited decreased high-shear viscosities compared to the other PEIs, lending to promising industrial applications for the zinc-endcapped branched and linear PEIs for high temperature applications. Additional engineering thermoplastics in the form of bio-based polyureas exhibited mechanical properties similar to those of non-bio-based polyureas. The isocyanate-free synthetic route incorporated an essential urea degradation mechanism at elevated temperatures to produce isocyanic acid, which then reacted with amines to produce linear polyurea thermoplastics. Urea provided a sustainable and bio-friendly reagent for high molecular weight, isocyanate-free polyureas. Poly(propylene glycol) triamine enabled the long-chain branching of thermoplastic polyureas. Differential scanning calorimetry (DSC) showed no change in Tg for the series; however, melting peaks decreased in intensity as the branching concentration increased, indicating a reduction in crystallinity. Tensile testing eluded to a decrease in ultimate stress values for higher branching concentrations, while melt rheology showed significant differences in melt viscosities. Viscosities increased markedly with an increase in branching concentration, signifying greater entanglement and stronger physical crosslinks for the branched polyureas. Further analysis of possible isocyanate-free routes led to the use of 1,1'-carbonyldiimidazole (CDI) to generate polyureas and polyurethanes. CDI, known in the literature for its use in amidation and functionalization reactions, enabled the production of well-defined and stable polyurethane monomers. The functionalization of butanediol with CDI yielded an electrophilic biscarbamate monomer, bis-carbonylimidazolide (BCI), suitable for further step-growth polymerization in the presence of amines. The reaction of this novel monomer with aliphatic diamines produced thermoplastic polyurethanes with high thermal stability, tunable glass transition temperatures based on incorporation of flexible polyether segments, and creasable thin films. It is envisioned that CDI functionalized diols will afford access to various polymeric backbones without the use of toxic isocyanate-containing strategies. Additionally, non-isocyanate polyurethane (NIPU) foams were produced from BCI monomers without the need of blowing agents, catalysts, or solvents. These materials offered an alternative to existing foaming technology, which typically employed isocyanates. Polyurethanes were foamed through a CO2 thermal decomposition mechanism involving the BCI monomers. We investigated two series of polyurethane foams with a tunable Tg range from ~0 °C to ~110 °C. We found that the incorporation of aromatic amines vastly altered the foam thermomechanical properties, and the resulting foams were closed-cell in nature. / Doctor of Philosophy / Step-growth polymers play a significant role in commercial and industrial applications. On-going work in this field focuses on sustainability, biodegradability, and improved processability. This dissertation encompasses the improvement and innovation of current and novel engineering thermoplastics and foams. The careful purification and step-growth synthetic strategies herein, afforded targeted molecular weights for analysis of linear and long-chain branched (LCB) polyetherimides (PEIs). Further analysis of LCB-PEIs, with monovalent and divalent ionic endgroups, provided an opportunity to study the effect of ionic interactions and physical crosslinks at high temperatures (>300 °C). The long branches improved the melt processability compared to linear analogues at equivalent molecular weights. The challenge to investigate polyurethanes using non-isocyanate methodologies offered an opportunity to apply fundamental small-molecule, organic synthesis to macromolecular science. 1,1'-Carbonyldiimidazole (CDI) provided a platform to generate polymeric chains from industrially relevant monomers. Additional testing serendipitously discovered the generation of CO2 upon thermal degradation of the novel monomers. Harnessing the release of CO2, during the gelation of polyurethanes, provided an isocyanate-, catalyst-, and solvent-free synthetic route towards polyurethane foams that boasts scalability and industrial relevance.

Phenol-formaldehyde (PF) resole and polymeric diphenylmethane diisocyanate (PMDI) are two commonly used exterior thermosetting adhesives in the wood-based composites industry. There is an interest in combining these two adhesives in order to benefit from their positive attributes while also neutralizing some of the negative ones. Although this novel adhesive system has been reportedly utilized in some limited cases, a fundamental understanding is lacking. This research serves this purpose by investigating some of the important aspects of this novel adhesive system. The adhesive rheological and viscometric properties were investigated with an advanced rheometer. The resole/PMDI blends exhibited non-Newtonian flow behavior. The blend viscosity and stability were dependent on the blend ratio, mixing rate and time. The adhesive penetration into wood was found to be dependent on the blend ratio and correlated with the blend viscosity. By using dynamic mechanical analysis, the blend cure speed was found to increase with the PMDI content. Mode I fracture testing of resole/PMDI hybrid adhesive bonded wood specimens indicated the dependence of bondline fracture energy on the blend ratio. The 75/25 PF/PMDI blend exhibited a high fracture energy with a fast cure speed and processable viscosity. Exposure to water-boil weathering severely deteriorated the fracture energies of the hybrid adhesive bondlines. More detailed chemistry and morphological studies were performed with cross-polarization nuclear magnetic resonance and 13C, 15N-doubly labeled PMDI. A spectral decomposition method was used to obtain information regarding chemical species concentration and relaxation behavior of the contributing components within the major nitrogen resonance. Different urethane concentrations were present in the cured blend bondlines. Water-boil weathering and thermal treatment at elevated temperatures (e.g. > 200°C) caused reduced urethane concentrations in the bondline. Solid-state relaxation parameters revealed a heterogeneous structure in the non-weathered blends. Water boil weathering caused a more uniform relaxation behavior in the blend bondline. By conducting this research, more fundamental information regarding the PF/PMDI hybrid adhesives will become available. This information will aid in the evaluation of, and improve the potential use of PF/PMDI hybrid adhesives for wood-based composites. / Ph. D.

La polymérisation anionique par activation du monomère permet d’accéder à une large gamme de polyéthers en utilisant un système amorçant à base d’un nucléophile associé au triisobutylaluminium. Cette voie a permis d’accéder à des chaînes polyéthers fonctionnalisées par des groupements hydroxyle à chaque extrémité. La (co)polymérisation de l’éther allylglycidique avec d’autres éthers cycliques a été réalisée puis les (co)polymères correspondants ont été post-fonctionnalisés pour introduire en particulier des fonctions cyclo-carbonate destinées à réagir avec des amines pour générer des fonctions hydroxyuréthane et ainsi préparer des matériaux type polyuréthane par une chimie sans isocyanate. Enfin des dérivés du pin, de la famille des acides résiniques, ont été modifiés chimiquement pour élaborer des matériaux de type résine époxyde et polyuréthane sans isocyanate. La polymérisation anionique par activation du monomère a également pu être réalisée sur un monomère époxydé issu de cette ressource. / Monomer-activated anionic polymerization allows the obtention of versatile polyethers using nucleophilic species in the presence of a Lewis acid, i.e. triisobutylaluminium. This method enables the synthesis of α-,ω-plurihydroxytelechelic polyethers. The (co)polymerization of allyl glycidyl ether with various epoxides allowed the preparation of copolyethers with reactive side groups. A cyclo-carbonate functionalization was carried out in order to introduce hydroxyurethane functions by reaction with amines. This reaction allows the preparation of isocyanate-free polyurethane. Finally, resinic acids were modified chemically to prepare epoxy resins and isocyanate-free polyurethanes. A polyether based on epoxidized resinic derivatives was also synthesized by ring-opening anionic polymerization and monomer activation.

京都大学 / 0048 / 新制・論文博士 / 博士(工学) / 乙第13241号 / 論工博第4179号 / 新制||工||1720(附属図書館) / 京都大学大学院工学研究科高分子化学専攻 / (主査)教授 吉崎 武尚, 教授 中村 洋, 教授 古賀 毅 / 学位規則第4条第2項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

Proteomics based on liquid chromatography coupled to mass spectrometry has developed rapidly in the last decade and become a powerful tool for protein mixtures analysis. LC-MS based proteomics involves four steps, sample preparation, liquid chromatography, mass spectrometry and bioinformatics. Improvements in each step have extended its applications to new biological research areas. This dissertation mainly focuses on method developments in both qualitative and quantitative proteomics. The first part of this dissertation focuses on qualitative analysis of T. gondii Parasitophorous Vacuole Membrane (PVM) proteins, which is very important for T. gondii’s survival. The hypothesis of this study is that proteomic approaches coupled with immunoprecipitation using polyclonal antisera as affinity reagents can successfully characterize the proteome of the T. gondii PVM. The “Three-layer Sandwich Gel Electrophoresis” (TSGE) protocol, was developed to contend with efficient salt removal and protein concentration from challenging samples. Furthermore, the TSGE coupled to 2D-LC-MS/MS was proven to be effective with the proteomic analysis of complex protein mixtures like T. gondii whole cell lysate, allowing for high-throughput protein analysis from complex samples. By using the TSGE-2D-LC-MS/MS methodology, we successfully identified 61 proteins from the PVM samples and constructed the PVM proteome. The second part of this dissertation describes a novel method for selecting an appropriate isocyanate reagent for potential quantitative proteomics application. Our hypothesis is alteration of isocyanate structure will change fragmentation pattern and ESI property of isocyanate modified peptides. The CID property of N-terminal modified peptides by phenyl isocyanate (PIC), phenethyl isocyanate (PEIC) and pyridine-3- isocyanate (PyIC) was systematically studied using LC-ESI-MS/MS. We observed that adjustment of isocyanate structure changed both ESI and fragmentation characteristic of modified peptides. We rationalized the decrease of protonation of PIC and PEIC modified peptides results from the neutral property of the both reagents. The electron withdrawing feature of PyIC leads to significant reduction of fragments during CID. Therefore, we designed a new isocyanate reagent, 3-(isocyanatomethyl) pyridine (PyMIC). The results revealed that PyMIC modified peptides had more suitable ESI properties and generated more sequence-useful fragments compared to PIC, PyIC and even unmodified peptides. PyMIC is a more appropriate labeling reagent for quantitative proteomics applications.

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.