The purpose of this study was to utilise lignin as a partial substitute for phenol in PF resins. To achieve this, initially brown rot lignin was produced by a bioconversion technique. During the course of the study, it became clear that the production of brown rot lignin had a limited success. Since brown rot lignin could not be obtained in sufficient quantity and purity by a bioconversion method, other alternative lignin production methods, as well as commercially available lignin, were chosen; namely production of lignin from black liquor and Alcell® (organosolv) lignin. Before performing production of resin formulations, the lignin sources were characterised in terms of reactivity and physical properties of lignins. Both lignins had a similar reactivity, but organosolv lignin was found to be more pure, with a low ash content. Since isolation of lignin from black liquor in laboratory conditions is more complex and requires more time, it was decided to use organosolv lignin for subsequent production of lignin-based reSIns. The lignin was introduced to the resin in two different ways. The first method was the replacing of a certain percentage of phenol with lignin (as supplied) directly into resins. In the second method, lignin was modified prior to resin manufacture by phenolation. Different degrees of phenol substitution (from 5% to 60%) were tried for the production of lignin-based resins. Bond qualities of lignin-phenol-formaldehyde (LPF) , phenolated-ligninformaldehyde, commercial phenol-formaldehyde (PF _com) and laboratory made phenol-formaldehyde (PF _made) resins were assessed by using an Automatic Bonding Evaluation System (ABES), prior to production of particleboards, in order to eliminate some of the poor quality resins. The effect of press temperature and time on bond strength appeared to be highly significant, as the lignin substitution levels increased. Up to 30% phenol substitution was achieved without sacrificing bond strength. The bond strength values of phenolated-lignin-formaldehyde resins were similar to commercial phenol-formaldehyde and laboratory made phenolformaldehyde resins, but better than the LPF resins. It was apparent that resins containing a high level of lignin substitution gave the poorest bond strength values. From these results, some of the resins were eliminated, prior to particleboard production. In order to evaluate the quality of lignin-based resins, particleboards were produced and mechanical and physical tests performed. Effect of press platen temperature (140°C, 160°C, 180°C) and press cycle time (5 min, 8 min, IS min) on the mechanical properties of particleboard, produced by using lignin-based resins, were investigated. It was found that particleboards bonded with up to 30% lignin content resins gave similar mechanical and physical properties to commercial phenolformaldehyde resin, as long as a sufficient heating regime and time were applied.

Urea formaldehyde (UF) resins are widely used as adhesives for wood-based composites. These thermosetting polymers have advantages of relative low price, fast curing speed, and relative good bonding performance. However, UF resin bonded composites are designed for interior applications due to its weak water resistance. Moreover, traditional prevalent ways for recycling wood-based composites face problems caused by UF resins. In this project, the reuse of cured UF resins was systematically studied. The verification and characterization of crystalline structures in cured UF resins were conducted. The results showed that the crystalline regions were accounted for nearly 14.48% in a typical 1.2 formaldehyde to urea (F/U) molar ratio UF resin. The details of the resin crystalline regions, such as grain sizes and interplanar spacing (d-spacing), were characterized. The crystalline structures, nevertheless, did not affect the UF resin hydrothermal hydrolysis in this study. The reuse of cured UF resin was started with a hydrothermal hydrolysis. Under 140 °C and 2 h of hydrothermal process, 20 mL of 30 w.t. % formaldehyde water solution was able to depolymerize up to 1.7 g of cured UF resin. The hydrolyzed formaldehyde solutions were directly used as normal formaldehyde solutions for UF resin synthesis. The synthesized resin (named as UUF resin) contained about 6 w.t. % of cured UF resin and presented similar chemical structures and bonding performance as normal UF resins. Hybrid resins made of UUF resin and polymeric 4-4 diphenyl methane diisocyanate (pMDI) were prepared. The pMDI was found evenly dispersed in the hybrid resins by using acetone as its solvent. These hybrid resins resulted in faster curing and stronger bonding performance than pure UUF resins. Furthermore, the hybrid resin was used in a new bonding design, which used southern pine wood radial section features. This design generated finger joint like bonding interfaces by hot pressing two resin coated wood radial sections. The bonding strength and bond line stability were enhanced by this design.

Thousand of new substances with unknown environmental effect are produced and used daily. Many of them are deliberately or by negligence released and deposited into the environment where they could undergo different transport and degradation mechanisms. They are able to affect different types of organisms, as well as humans. For this reason, the awareness of the problems, associated with pollution of all environmental compartments is growing. The environmental impact of monomer formaldehyde resins, which are produced for commercial use, on the environment were studied in this research. For the purposes of ecotoxicological evaluation samples of melamine-formaldehyde and urea-formaldehyde resin were chosen and three toxicity tests were run: acute test with measurement of inhibition of the mobility of Daphnia magna, the acute test with luminescent bacteria Vibrio fischeri and acute test with measurement of inhibition of oxygen consumption by activated sludge. For more comprehensive assessment of the impact of these substances on the environment, biodegradability was also determined. Both tested substances showed minor hazardous impact to testing organisms and it can be concluded, that these substances should not present a significant risk to the environment.

<p> High molecular weight poly(ethylene oxide) (PEO) is used in conjunction with a cofactor such as phenol formaldehyde resin (PFR) as flocculants for newsprint manufacture. The objectives of the work described in this thesis were to prepare flocculants superior to PEO and to determine the flocculation mechanism. A series of novel comb copolymers consisting of a polyacrylamide backbone with short pendant poly(ethylene glycol) (PEG) chains was prepared and characterized. Additionally, polymerization conversion curves and reactivity ratios were measured. An interesting finding was that the reactivity of the macromonomer in free radical copolymerization decreased with PEG chain length. </p> <p> Flocculation results with both model latex dispersions and commercial wood pulp suspensions showed that copolymer chain length was the most important variable ; molecular weights greater than 3 million were required for good flocculation. On the other hand, the PEG pendant chains could be as short as 9 ether repeat units. Also, only 1 to 2 PEG chains for every 100 acrylamide backbone moieties were required. </p> <p> No published flocculation mechanisms could predict all the behaviors of the PEO or copolymer system. A new mechanism called complex bridging was proposed. According to this mechanism PEO or copolymer chains aggregate in the presence of cofactor to form colloidally dispersed polymer complex which heteroflocculates with the colloidal particles. </p> <p> Given in this work is the first explanation of the requirement for extremely high PEO or copolymer molecular weights for flocculation. It is proposed that polymer chains with molecular weights less than 106 collapse in the presence of PFR to an inactive precipitate before flocculation can occur whereas complexes based on very high molecular weight PEO collapse slowly enough to permit flocculation. </p> <p> Published mechanistic studies are hindered by the fact that PFR has poorly defined structures. It is shown for the first time in this work that welldefined, linear, poly(p-vinyl phenol) (PVPh) is an effective cofactor. </p> / Thesis / Doctor of Philosophy (PhD)

The objective of this study was to investigate the effects of melamine and ether contents on the curing and performance properties of UF resins as binders for wood composites. Various UF and UMF resins were synthesized with three different synthesis procedures. These resins were examined by 13C NMR, rheometer, and other methods and evaluated as particleboard binders. Three-layer particleboards were prepared with the resins catalyzed with various catalysts and levels, applied in face and core layers. The board test results were compared. Only about half of added melamine had reacted with formaldehyde. UMF resins were found to be catalyzed with stronger catalysts at suitable levels depending on melamine levels and on which layer of particleboard the UMF resins are to be applied. Even catalyzed with a stronger catalyst, the curing rates of UMF resins were still slower, and storage stabilities were shorter than UF resins, but the pot lives were longer, and internal bond strength and water resistance were higher. Moreover, resins synthesized with procedures 2 and 3 showed obviously longer storage times, longer pot lives, and longer gel times, and the particleboards bonded with these resins showed significant improvements in internal bond strength and water absorption values but the formaldehyde contents increased. The increased formaldehyde content test values indicated that linear methylene-ether groups in UF resins decompose in the hot-pressing of boards to emit formaldehyde, most of which is not captured back into the UF resin matrix. Uron-type methylene-ether groups decompose in the hot-pressing of boards to participate in the curing process and enhance the bonding of boards, but it could also emit extra formaldehyde which may not be effectively captured by UF resins but more effectively by UMF resins if the amount of melamine is high enough because of the increased reactive capacities of melamine. The results of this research offered a new hypothesis that the linear methyleneether bonds in UF resins might be a major contributor of the high free formaldehyde contents of particleboards. Decreasing the linear methylene-ether groups contents might effectively bring down the formaldehyde content of boards.

The purpose of this research was to determine the effects of cellulose nanocrystals (CNCs), as potential additives, on the properties and performance of phenol–formaldehyde (PF) adhesive resin. The steady-state viscosity of a commercial PF resol resin and three CNC–resin mixtures, containing 1–3 wt % CNCs, based on solids content, was measured with a rheometer as a function of shear rate. The viscosity of the PF resin itself was independent of shear rate. The viscosity–shear rate curves of the CNC–resin mixtures showed two regions, a shear thinning region at lower shear rates and a Newtonian region at higher shear rates. The low-shear-rate viscosity of the resin was greatly increased by the CNCs. The structure of the CNC–resin mixtures under quiescent conditions was analyzed by polarized light microscopy. The mixtures contained CNC aggregates, which could be disrupted by ultrasound treatment. The curing progressions of the resin and CNC–resin mixtures were analyzed by non-isothermal differential scanning calorimetry (DSC). The DSC curves showed two exotherms followed by an endotherm. The energy of activation for the first exotherm was reduced by the CNCs whereas the energy of activation for the second exotherm was not affected by the CNCs. Increasing CNC contents caused higher degrees of reaction conversion during the first curing stage and a greater loss of sample mass, attributed to formaldehyde release during resin cure. For analysis of the mechanical properties during and after cure, sandwich-type test specimens were prepared from southern yellow pine strips and the resin and CNC–resin mixtures. The mechanical properties of the test specimens were measured as a function of time and temperature by dynamic mechanical analysis (DMA). The time to incipient storage modulus increase decreased and the rate of relative storage modulus increase increased with increasing CNC content. The ultimate sample stiffness increased with increasing CNC content for CNC contents between 0 and 2 wt %, which was attributed to mechanical reinforcement of the resin by the CNCs. At a CNC content of 3 wt %, the ultimate sample stiffness was lower than at a CNC content of 2 wt % and the second tan δ maximum occurred earlier in the experiment, indicating an earlier onset of vitrification. The lower ultimate sample stiffness was attributed to premature quenching of the curing reactions through CNC-induced depression of the vitrification point. For analysis of the fracture performance, double cantilever beam test specimens were prepared from southern yellow pine beams and the resin and CNC–resin mixtures, using different hot-pressing times. Fracture energies were measured by mode I cleavage tests. Bondline characteristics were analyzed by light microscopy. At a hot-pressing time of 10 min, the fracture energy decreased with increasing CNC content, whereas it stayed constant for CNC contents between 1 and 3 wt % at a hot-pressing time of 8 min. The bondlines of resin mixtures containing CNCs exhibited voids, whereas those of the pure resin did not. CNCs had both benefitial and detrimental effects on the properties and performace of PF resin. / Master of Science

Diploma's thesis describes resolution of cause technological problems in mineral wool manufacturig in company Saint-Gobain Orsil. Main attention is paid to thermal and volatile process in mineral wool from filtration chamber and common commercial sales. Samples of mineral wool were characterizated by thermal analysis (simultaneous TG-DTA), effluent gas analysis (EGA), infrared spectroscopy (FT-IR), electron microscopy (SEM) and X-ray diffraction (XRD). Thermal analysis experiments was used to check thermal volatile processes. Technological problem of burning is linked with rise of isocyanic acid.

Les ROS (Reactive Oxygen Species), tels H2O2, HO● et O2-●, sont produites naturellementpar le métabolisme des êtres vivants. Cependant, elles peuvent apparaître en trop grandesquantités dans le cas de certaines maladies (Alzheimer, Parkinson, scléroses, cancers). Lasurproduction de ROS conduit à une mortalité des cellules plus élevée.Certains micro-oragnismes possèdent une enzyme à base de Mn capable de catalyser laréaction de dismutation du H2O2 en O2 et H2O. Plusieurs molécules ont été synthétisées pourreproduire ce procédé, cependant très peu d'entre elle sont actives en environnement aqueux.Récemment, des espèces synthétiques du Mn ont été introduites dans des silicesvoient même leur activité catalytique augmenter. Afin de perséverer dans cette voie, cettethèse présente de nouveaux composés de MnII (dinucléaire et chaîne) et MnIII(tetranucléaire) basés sur ce concept. Ils sont dotés de ligands fluorescents, ajoutés pour desfin théragnostiques. Ces composés ont été insérés dans des nanoparticules (NPs) de silice ethybrides carbone-silice afin, de permettre leur vectorisation et d'étudier la compatibilité desNPs hybrides avec ce type de système.Le travail fourni explore les propriétés magnétiques des complexes, les propriétésluminescentes des composés et matériaux et montre la bonne insertion des composés dans lesNPs hybrides, ne nécessitant pas, contrairement aux NPs de silice pure, de fonctionnalisationsupplémentaire pour la rétention des complexes. Il met aussi en évidence l'activité descomposés du Mn dans l'acétonitrile et ouvre des pistes pour une optimisation des systèmeshybrides en milieu aqueux.Le travail fourni explore les propriétés magnétiques des complexes, les propriétésluminescentes des composés et matériaux et montre la bonne insertion des composés dans lesNPs hybrides, ne nécessitant pas, contrairement aux NPs de silice pure, de fonctionnalisationsupplémentaire pour la rétention des complexes. Il met aussi en évidence l'activité descomposés du Mn dans l'acétonitrile et ouvre des pistes pour une optimisation des systèmeshybrides en milieu aqueux. / ROS (Reactive Oxygen Species), such as H2O2, HO● and O2-●, are naturally produced by themetabolism of living beings. However, they can appear in large quantities in the case of certaindiseases (Alzheimer's, Parkinson's, sclerosis, cancer). Overproduction of ROS leads to highercell mortality.Some microorganisms have an Mn-based enzyme capable of catalyzing the disproportionationreaction of H2O2 into O2 and H2O. Several molecules have been synthesized to reproduce thisprocess, however very few of them are active in aqueous environment. Recently, synthetic Mn species have been introduced into mesoporous silica to protect themfrom the environment. Thus, these complexes of Mn are stable and even see their catalyticactivity increase. In order to persevere in this way, this thesis presents new compounds ofMnII (dinuclear and chain) and MnIII (tetranuclear) based on this concept. They havefluorescent ligands (9-anthracene carboxylate), added for theragnostic purposes. Thesecompounds were inserted into silica nanoparticles (Nps), resol (a polyphenol resin) -silica andcarbon-silica hybrids in order to allow their vectorization and to study the compatibility ofhybrid NPs with this type of system.This work explores the magnetic properties of the complexes, the luminescent properties of thecompounds and materials and shows the good insertion of the compounds into the hybrid NPs,not requiring, in contrast to pure silica NPs, additional functionalization for the retention of thecomplexes. It also highlights the activity of Mn compounds in acetonitrile and paves the wayfor optimizing hybrid systems in aqueous media.

The aim of this study was to investigate rubber toughening of resol type phenol-formaldehyde resin. For this purpose, phenolic resin was first modified by only acrylonitrile butadiene rubber, and then by using nitrile rubber together with 3-aminopropyltriethoxysilane. Test specimens were prepared by mixing and casting of liquid phenolic resin in three groups. In the first one, neat phenolic resin specimens were produced. In the second group, phenolic resin was modified with 0.5, 1, 2, and 3 wt.% nitrile rubber, while in the last group modification was carried out by using 0.5 wt.% nitrile rubber together with 1, 2, and 4wt.% amino silane (with respect to nitrile rubber). All specimens were heat cured in the oven. In order to observe behaviors of the specimens, Three-Point Bending, Charpy Impact, Plane-Strain Fracture Toughness, and Dynamic Mechanical Analysis tests were conducted according to the related ISO standards for all specimens groups. Scanning Electron Microscopy was also used for the fractographic analysis of some samples. It can be concluded that, although there were problems in mixing and casting of liquid resol type phenolic resin, its toughness could be improved by using nitrile rubber and amino silane. Modification by using nitrile rubber and amino silane together was much more effective than by using only nitrile rubber. In this synergistic case for instance, Charpy impact strength and fracture toughness values of the neat phenolic specimens were increased 63% and 50%, respectively. SEM studies indicated that the main rubber toughening mechanism was shear yielding observed as deformation lines especially initiated at the domains of nitrile rubber and amino silane.

Submitted by Ana Laura Soler Cunha Buzo (analaurasolercunha@gmail.com) on 2018-09-28T22:21:33Z No. of bitstreams: 1 DISSERTAÇÃO FINAL .pdf: 3047917 bytes, checksum: 4b9d9190322307f4e23c7de4f21936e9 (MD5) / Approved for entry into archive by Cristina Alexandra de Godoy null (cristina@adm.feis.unesp.br) on 2018-10-01T13:05:23Z (GMT) No. of bitstreams: 1 buzo_alsc_me_ilha.pdf: 3047917 bytes, checksum: 4b9d9190322307f4e23c7de4f21936e9 (MD5) / Made available in DSpace on 2018-10-01T13:05:23Z (GMT). No. of bitstreams: 1 buzo_alsc_me_ilha.pdf: 3047917 bytes, checksum: 4b9d9190322307f4e23c7de4f21936e9 (MD5) Previous issue date: 2018-07-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O desenvolvimento de estudos para produção de derivados de madeira tem representado uma real alternativa para contribuir as políticas de sustentabilidade, principalmente de espécies arbóreas nativas. Nesse contexto, o reaproveitamento de resíduos lignocelulósicos tem contribuído como uma alternativa para a produção industrial de painéis de madeira. Dentro desse contexto este trabalho se constitui do estudo para produção e avaliação de painéis aglomerados, empregando-se partículas de bagaço de cana-de-açúcar (Saccharum officinarum) e partículas de madeira de pinus (Pinus taeda; Pinus elliottii) e utilizando-se dois tipos de aglutinantes, o Poliuretano derivado do óleo de mamona (PU-M) e a Resina Ureia-formaldeído (UF). Para produção dos painéis foram propostos diferentes tratamentos com variações entre as proporções de massas das partículas, densidade nominal dos painéis de 0,80 g/cm3 e pressão de prensagem de 50 kgf/cm2 durante 10 min. As misturas de partículas foram utilizadas com 10% de umidade para o adesivo PU-M e 3% de umidade para a resina UF ambos com um conteúdo de 10% em relação à massa seca das partículas. Para prensagem dos painéis com PU-M empregou-se 100 ºC e para os painéis com UF 130 ºC. Os painéis foram submetidos a ensaios para avaliação das propriedades físicas (densidade, umidade e inchamento) e mecânicas (módulo de elasticidade, módulo de ruptura à flexão e tração perpendicular) de acordo com a ABNT NBR 14810-1 e 2 (2013). Os resultados obtidos evidenciaram ser possível a utilização das partículas provenientes do bagaço de cana e de pinus para a produção de painéis aglomerados de alta densidade. Verificou-se que os painéis produzidos com o poliuretano apresentaram maior eficiência e suas propriedades físicas e mecânicas encontram-se compatíveis com os requisitos da Norma Brasileira para painéis do tipo P6 - Painéis estruturais para uso em condições severas de carga, em condições secas. Entretanto, verificou-se que os painéis produzidos com UF podem ser classificados como painéis do Tipo P2 - Painéis não estruturais para uso em condições secas. / The development of studies for the production of wood derivatives has represented a real alternative to improve sustainability policies, mainly of native tree species. In this context, the reuse of lignocellulosic waste has contributed as an alternative to the industrial production of wood panels. This way, this work aims to produce and evaluate chipboards using particles of sugarcane bagasse (Saccharum officinarum) and particles of pine wood (Pinus taeda; Pinus elliottii) and using two types of binders, the Polyurethane derived from castor oil (PU-Castor) and Urea formaldehyde resin (UF). Different treatments were proposed for the production of boards with variations between the particle mass ratios, panels’ nominal density of 0.80 g/cm3 and pressing pressure of 50 kgf/cm2 for 10 minutes. Particle mixtures were used at 10% moisture for the PU-Castor adhesive and 3% moisture for the UF resin both with a content of 10% relative to the dry mass of the particles. For the pressing of panels with PU-Castor was used 100 °C and of panels with UF was used 130 °C. The boards were submitted to tests to evaluate the physical properties (density, moisture and swelling after 24 hours) and mechanical (modulus of elasticity, modulus of resistance to bending and perpendicular traction) according to the ABNT NBR 14810-1 and 2 (2013). The results showed that it is possible to use particles from sugarcane bagasse and pine wood for high density chipboards production. It was found that the boards produced with polyurethane presented higher efficiency and their physical and mechanical properties are compatible with the requirements of Brazilian Standard Regulations for P6 boards (Structural boards for use under severe load conditions for dry conditions use). However, it has been found that panels made with UF can be classified as type P2 panels – Non-structural boards for dry conditions use. / CAPES - DS