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The biological treatment of pulp and paper mills effluents results in the production of waste secondary sludge which is hard and costly to dewater and dispose. Secondary sludge, which is structurally comparable to the municipal sewage sludge, is composed of microbial cells, organic woody materials, and ash. In this work, the use of this waste biosolid as renewable and cost-cutting filler in the composite industry is proposed. Moreover, the effect of enzymatic treatment of the waste biosolid on the final properties of the manufactured biocomposite is studied. The high protein content of the secondary sludge (35 ± 5%) and the surface thermodynamics measured by Inverse Gas chromatography (IGC) led us to choose Nylon 11 as the main polymeric matrix. The biocomposites samples produced by compounding and injection molding of different mixtures of dried secondary sludge and Nylon were tested. The results of mechanical strength tests showed that a 10% sludge content does not lead to any significant deterioration of either tensile or flexural strengths. Therefore, it is concluded that the secondary sludge may be used as filler to reduce the cost while maintaining the mechanical properties of Nylon. Enzymatic modification of the waste biosolid to advance its application from cheapening filler to reinforcing filler has also been proposed in this work. Lipase and laccase utilized for the modification of the sludge in order to reduce the hydrophobicity and increase the molecular weight, respectively. Lipase application did not lead to any significant changes in either tensile or flexural strengths. This is attributed to the rather low content of lipids in the sludge. On the other hand, enzymatic modification of the sludge by laccase which increases the molecular weight of the existing lignins, resulted in significant improvement of the flexural strength of the manufactured biocomposite.

The biological treatment of pulp and paper mills effluents results in the production of waste secondary sludge which is hard and costly to dewater and dispose. Secondary sludge, which is structurally comparable to the municipal sewage sludge, is composed of microbial cells, organic woody materials, and ash. In this work, the use of this waste biosolid as renewable and cost-cutting filler in the composite industry is proposed. Moreover, the effect of enzymatic treatment of the waste biosolid on the final properties of the manufactured biocomposite is studied. The high protein content of the secondary sludge (35 ± 5%) and the surface thermodynamics measured by Inverse Gas chromatography (IGC) led us to choose Nylon 11 as the main polymeric matrix. The biocomposites samples produced by compounding and injection molding of different mixtures of dried secondary sludge and Nylon were tested. The results of mechanical strength tests showed that a 10% sludge content does not lead to any significant deterioration of either tensile or flexural strengths. Therefore, it is concluded that the secondary sludge may be used as filler to reduce the cost while maintaining the mechanical properties of Nylon. Enzymatic modification of the waste biosolid to advance its application from cheapening filler to reinforcing filler has also been proposed in this work. Lipase and laccase utilized for the modification of the sludge in order to reduce the hydrophobicity and increase the molecular weight, respectively. Lipase application did not lead to any significant changes in either tensile or flexural strengths. This is attributed to the rather low content of lipids in the sludge. On the other hand, enzymatic modification of the sludge by laccase which increases the molecular weight of the existing lignins, resulted in significant improvement of the flexural strength of the manufactured biocomposite.

Durant ces dernières décennies, de nombreuses actions de recherche au niveau international se sont intéressées aux biomatériaux présentant d'une part des caractéristiques équivalentes voire parfois supérieures à celle des produits d'origine fossile et d'autre part le caractère renouvelable des ressources est un atout environnemental. De plus, le problème des sédiments marins et fluviaux est un problème mondial. La gestion des sédiments de dragage constitue ainsi une préoccupation générale en raison des quantités produites et de leur nuisance potentielle. Dans ce travail, une étude expérimentale est menée sur la valorisation des sédiments marins à des pourcentages variant de 0% à 20% comme une charge minérale dans une matrice agrosourcée et d'apprécier leur influence sur les propriétés physicomécaniques, thermiques ainsi que sur la durabilité des composites élaborés HESM (hémoglobine/ sédiments Marins). Les résultats montrent que le module en compression, en flexion, en traction et la résistance à la compression ont été améliorés lors de l'ajout des sédiments marins, par contre la résistance à la traction et la résistance à la flexion ont été diminuées par rapport au matériau de référence. L'étude microstructurelle a permis de justifier l'effet de l'ajout des sédiments dans la matrice sur les propriétés mécaniques. Quant à la caractérisation thermique des biocomposites, les résultats montrent l'amélioration de la stabilité thermique des composites par rapport au polymère pur. Concernant la durabilité, l'ajout des sédiments marins n’a presque pas influencé les propriétés de durabilité et que le matériau chargé ou non ne doit pas être exposé aux intempéries sans protection. La modélisation par éléments finis du comportement mécanique en compression a donné des résultats satisfaisants permettant de valoriser ce nouveau biocomposite comme un revêtement de sol / In recent decades, many research activities at the international level have focused on biomaterials with one hand equivalent characteristics and sometimes even higher than that of fossil products and secondly renewability of resources is an asset environmental. In addition, the problem of marine and river sediments is a global problem. Dredged sediment management is thus a general concern because of the quantities produced and their potential nuisance. In this work, an experimental study is conducted on the development of marine sediments to percentages ranging from 0% to 20% as a mineral filler in an agro-sourced matrix and appreciate their influence on the physical-mechanical, thermal and Sustainability elaborate composite HESM (hemoglobin / Marine sediments). The results show that the compressive modulus, flexural, tensile and compressive strength were improved when the addition of marine sediments by against the tensile strength and the flexural strength were decreased compared the reference material. The microstructural study to justify the effect of the addition of sediments in the matrix on the mechanical properties. As for the thermal characterization of biocomposites, the results show the improvement in the thermal stability of the composite relative to the pure polymer. Regarding sustainability, the addition of marine sediments has not almost influenced the durability properties and the charged material or not should not be exposed to the elements without protection. The finite element modeling of the mechanical behavior in compression has yielded satisfactory results to develop this new biocomposite as a floor covering

QC 20120315

Orthopaedic reconstruction often involves the surgical introduction of structural implants that provide for rigid fixation, skeletal stabilization, and bone integration. The high stresses incurred by these implanted devices have historically limited material choices to metallic and select polymeric formulations. While mechanical requirements are achieved, these non-degradable materials do not participate actively in the remodeling of the skeleton and present the possibility of long-term failure or rejection. This is particularly relevant in cervical fusion, an orthopaedic procedure to treat damaged, degenerative or diseased intervertebral discs. A significant improvement on the available synthetic bone replacement/regeneration options for implants to treat these conditions in the cervical spine may be achieved with the development of primarily mineral biocomposites comprised of a bioactive ceramic matrix reinforced with a biodegradable polymer. Such a biocomposite may be engineered to possess the clinically required mechanical properties of a particular application, while maintaining the ability to be remodeled completely by the body. A biocomposite of Si-doped calcium phosphate (Si-CaP) and poly(ε-caprolactone) (PCL) was developed for application as such a synthetic bone material for potential use as a fusion device in the cervical spine. In this thesis, a method by which high mineral content Si-CaP/PCL biocomposites with interpenetrating matrices of mineral and polymer phases may be prepared will be demonstrated, in addition to the effects of the various preparation parameters on the biocomposite density, porosity and mechanical properties. This new technique by which dense, primarily ceramic Si-CaP/PCL biocomposites were prepared, allowed for the incorporation of mineral contents ranging between 45-97vol%. Polymer infiltration, accomplished solely by passive capillary uptake over several days, was found to be capable of fully infiltrating the microporosity of the sintered calcium phosphate ceramic. After infiltration, these biocomposite materials demonstrated an increase in compressive strength, flexural strength and Young’s modulus with increasing ceramic content and met design targets for use as a cervical fusion prosthesis. The biocomposite was amenable to shaping and drilling and was found to maintain its strength after 30 days immersion in Earle’s Balanced Salt. / Thesis (Ph.D, Mechanical and Materials Engineering) -- Queen's University, 2009-11-24 16:18:16.461

Dans cette étude, les matériaux composites poly 3-hydroxybutyrate-co-4-hydroxybutyrate (P34HB) / fibres de bambou et polybutylène succinate (PBS) / fibres de bambou ont été préparés en utilisant le mélangeur interne et le moulage par compression. Les propriétés thermo-mécaniques de P34HB et de PBS ont été caractérisées. Les fibres de bambou ont été modifiées par des traitements chimiques. Les propriétés mécaniques telles que la résistance à la traction, la résistance à la flexion, le module d’élasticité et les propriétés thermiques ont été étudiées. Pour les deux types de composites (P34HB et PBS), le module est significativement amélioré, cependant, la résistance du composite est légèrement diminuée. L'allongement à la rupture est plus faible que celui des polymères purs, ce qui indiquerait une bonne adhérence entre la matrice et les fibres. L'étude révèle que l'adhésion est améliorée avec les fibres modifiées avec le silane et l'acide acétique, ce qui entraîne une augmentation des propriétés mécaniques du matériau, par rapport à celles des composites renforcés avec des fibres non traitées. En outre, le taux de 20% de fibres est considéré comme la bonne composition de fibres pour garantir de bonnes propriétés thermo-mécaniques et une absorption d'eau faible.En étudiant ces matériaux composites, nous visons à produire des matériaux respectueux de l'environnement. De plus, l’abondance des fibres de bambou permettra de réduire le coût de la matière première. Ce travail porte principalement sur la modification des fibres de bambou afin d'améliorer les propriétés globales des composites et sur la comparaison de ces propriétés par rapport à celles des fibres non traitées. Pour atteindre une meilleure adhérence matrice-fibre, un agent de couplage et/ou compatibilisant peuvent être étudiés et utilisés dans une future étude. / In this study, poly 3,4 hydroxy butyrate (P34HB)/bamboo fibers and polybutylene succinate (PBS)/bamboo fibers composites were prepared by internal mixer and compression molding. P34HB and PBS were characterized with mechanical and thermal methods while bamboo fibers were modified with chemical treatments. Mechanical properties such as tensile strength, flexural strength, modulus and thermal properties were investigated. For both 2 kinds of composites (from P34HB and PBS), it was found that the modulus was significantly improved, however, the strength of the composite was slightly decreased and the elongation at break was a lower than the neat polymer suggesting that the adhesion between matrix and reinforcement should be improved more. The study reveals that modifying the fibers with both silane and acetic acid would improve the adhesion, resulting to the better mechanical properties of the material, compared with composites reinforced with untreated fiber or fiber treated with other methods. Also, 20 % of fiber content is regarded as the good composition of fiber to guarantee the good mechanical, water absorption and thermal properties.By taking advantage of P34HB, PBS and bamboo fibers, we aim to produce the material which is environmental friendly. Moreover, the abundant bamboo fibers can be used and these bamboo fibers will reduce the cost of the material. Within this work, we focus on the modification of bamboo fibers to reach our goal of improving the overall properties of the composites, compared with composites reinforced with untreated fibers. To achieve the better adhesion between fibers and matrix, coupling agent and compatibilizer may be used and studied in our future study.

L’objectif de ce travail de thèse est la formalisation des relations entre la structure et les propriétés de transfert de matière (sorption, diffusion, perméabilité) dans des matériaux biocomposites pour l’emballage alimentaire. Pour cela, la thèse se focalise sur deux questions scientifiques majeures : (i) comment évaluer les propriétés de transfert de vapeur d’eau et de gaz dans des particules végétales de taille micrométrique et (ii) comment formaliser l’influence de l’interphase sur les propriétés de transfert de matière en utilisant des approches expérimentales et de modélisation. Pour cela, a système composite modèle a été utilisé : un biocomposite polypropylène (PP) / particules de cellulose micrométrique produit par extrusion. La première partie de ces travaux est axée sur le développement d’une méthodologie fiable pour caractériser les propriétés de transfert dans des particules de taille micrométrique. Une nouvelle méthode ad hoc couplant microbalance à quartz et cellule d’absorption a été développée et comparée aux méthodes gravimétriques classiques telles que la DVS. La caractérisation fine de la taille / distribution en taille des particules est une étape essentielle pour garantir la fiabilité de l’estimation des paramètres de diffusion. Le deuxième objectif s’appuie sur une caractérisation quantitative fine de la structure 3D des matériaux composites (micro-tomographie X). En finalité, ces travaux de thèse permettent d’aller plus loin dans le développement de modèles prédictifs des relations entre structure et propriétés de transfert de matière, ce qui est l’étape nécessaire pour développer des matériaux biocomposites basés sur une approche d’ingénierie inverse. / The objective of this thesis is to formalize the relationships between the structure and mass transfer properties (sorption, diffusion, permeability) in biocomposites for food packaging. It raises two main scientific questions: (i) how to evaluate the mass transfer properties in micrometric size vegetal particles and (ii) how to formalize the impact of the interphase on mass transfer properties by using experimental and modeling approaches. For this purpose, a model system has been considered, i.e. a biocomposite polypropylene (PP)/ micrometric cellulose particles, produced by melt extrusion. The first part of this work focuses on the development of reliable methodologies to characterize mass transfer properties in micrometer size particles. A new method based on the use of a quartz crystal microbalance coupled to an absorption system has been developed and critically compared to classical methods such as DVS. The accurate characterization of the particle morphology distribution is a key point for estimating diffusivity parameters. The second objective is dedicated to the quantitative characterization of the 3D microstructure using X-ray micro-tomography. Structural parameters are used in biphasic and triphasic (consideration of the interphase) models of mass transfer. This thesis brings new knowledge in the modeling of structure / mass transfer properties relations in biocomposites, which is the necessary step for developing biocomposites based on a reverse engineering approach.

As the plastics sector moves towards sustainable growth and development, natural fibres start to play an important role as constituents in composite materials in several industries including automotives. However, drawbacks such as fibre-matrix incompatibility and poor fibre dispersion still exist. In this thesis, Kraft pulp fibre (KF)-Polylactic Acid (PLA) composites were prepared using thermal compounding and aqueous blending to study fibre-matrix interactions. Fibre surfaces were also modified to improve fibre dispersion and water absorption properties. A biorefinery lignin was added to PLA and high density polyethylene (HDPE) as a biofiller and potential interface modifier. Aqueous blended composites showed better mechanical and dynamic mechanical performance than the thermally compounded materials. The fibre surface modification improved dispersion and material properties at higher fibre content. Furthermore, the addition of lignin to polymers resulted in improved mechanical properties in both PLA and HDPE; however, lignin failed to improve interface bonding between KF and PLA.

As the plastics sector moves towards sustainable growth and development, natural fibres start to play an important role as constituents in composite materials in several industries including automotives. However, drawbacks such as fibre-matrix incompatibility and poor fibre dispersion still exist. In this thesis, Kraft pulp fibre (KF)-Polylactic Acid (PLA) composites were prepared using thermal compounding and aqueous blending to study fibre-matrix interactions. Fibre surfaces were also modified to improve fibre dispersion and water absorption properties. A biorefinery lignin was added to PLA and high density polyethylene (HDPE) as a biofiller and potential interface modifier. Aqueous blended composites showed better mechanical and dynamic mechanical performance than the thermally compounded materials. The fibre surface modification improved dispersion and material properties at higher fibre content. Furthermore, the addition of lignin to polymers resulted in improved mechanical properties in both PLA and HDPE; however, lignin failed to improve interface bonding between KF and PLA.