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The overall goal of this investigation was to elucidate specific structure-property relationships in perfluorosulfonate ionomers (PFSIs)-related materials. The project can be broken into two primary foci. First, we explored the current state of understanding related to morphology-property relationships in PFSIs with specific attention to the nano-scale organization of the ionic and crystalline domains. Specifically, the effect of uniaxial orientation on the structure and transport properties of Nafion® membranes was examined. Small angle X-ray scattering (SAXS) experiments on dry membranes that were uniaxially elongated showed a strong anisotropic morphology which was shown to persist over the swelling process without a significant relaxation. Herman's order parameters for the ionomer peak were strongly influenced by uniaxial deformation, which supports the presence of cylindrical rather than spherical morphology for ionic domains. Comparison of the water diffusion coefficients between unoriented and oriented samples revealed that uniaxial deformation of Nafion® membranes essentially enhances transport ability in one direction (i.e., the parallel to draw direction) and suppresses in the other two directions (i.e., two orthogonal directions relative to the stretching direction). Based on 1-dimensional analyses of oriented SAXS patterns at the azimuthal angle 90o, three recent models (lamellar model, semicrystalline rod-like model and fringed-micelle model) for the morphology of PFSIs were critically evaluated. The loss of meridional scattering, different orientation behavior of the crystalline and ionic domains, and inherent chain stiffness precludes the possibility of a chain-folded lamellar morphology. While the inter-aggregate dimensions remain constant at high draw ratios, the inter-crystalline spacings decrease significantly. Coupled with the distinctly different orientation behavior, these observations preclude the existence of crystallites solely within rod-like aggregates. While the worm-like ionic channel model was able to explain the behavior of SAXS and wide angle X-ray scattering (WAXS) relatively well, this model also had limitations such as (1) crystalline domains directly linked to the ionic domain (and thus a lack of amorphous domains) and (2) a presence of only a single ionic channel between two neighboring crystallites. Second, electroactive materials, specifically ionic polymer-metal composites (IPMCs) that undergo bending motions with the stimulus of a relatively weak electric field were fabricated. To understand the role of the nanoscale morphology of the membrane matrix in affecting the actuation behavior of IPMC systems, we evaluated actuation performance of IPMCs subjected to uniaxial orientation. The PFSI nanostructure altered by uniaxial orientation mimicked the fibrillar structure of biological muscle tissue and yielded a new anisotropic actuation response. It was evident that IPMCs cut from films oriented perpendicular to the draw direction yielded displacement values that were significantly greater than that of unoriented IPMCs. In contrast, IPMCs cut from films oriented parallel to the draw direction appeared to resist bending and yield displacement values that were much less than that of the unoriented IPMC. This anisotropic actuation behavior was attributed to the contribution of the nanoscale morphology to the bulk bending modulus. Overall, this study clearly demonstrated, for the first time, the importance of the nanoscale morphology in affecting/controlling the actuation behavior in IPMC systems. / Ph. D.

Submitted in fulfillment of the requirements for the degree of Doctor of Technology: Chemistry, Durban University of Technology, Durban, South Africa, 2015. / This thesis forms part of the Council for Scientific and Industrial Research, Forestry and Forest Products Research Centre (CSIR-FFP) biorefinery project which aims at developing and implementing novel industrial processes production of cellulose textile fibres. The focus of this study is to investigate the dissolution of South African Eucalyptus raw (unbleached) and final (bleached) dissolving pulp and saw dust wood in an ionic liquid (IL) 1-ethyl-3-methylimidazolium acetate [Emim][OAc] and the co-solvents [dimethylsulfoxide (DMSO)] or [dimethylformamide (DMF)] mixtures, to obtain regenerated cellulose by the further addition of water and acetone. The IL/co-solvent mixtures were able to dissolve the raw and final pulp samples at 120 ˚C for 6 hours whereas the sawdust wood dissolved in 10 hours. The IL/DMF mixture gave higher cellulose recoveries of 41.88 % for the raw pulp, 49.89 % for the final pulp sample and 32.50 % for sawdust wood while the IL/DMSO mixture gave a recovery of 15.25 % for the raw pulp sample, 36.25 % for the final pulp sample and 17.83 % for the sawdust wood sample. The regenerated cellulose materials were characterized by Fourier Transformer Infrared Spectroscopy (FTIR), Nuclear Magnetic Resonance (NMR), Scanning Electron Microscopy (SEM), Thermo gravimetric Analysis (TGA) and Powder X-Ray Diffraction (pXRD), and compared with a standard microcrystalline of cellulose. It was observed that the FTIR and NMR spectra of the regenerated cellulose and MCC were similar which then indicates that no chemical reaction occurred during the dissolution and regeneration process of cellulose. SEM and X-ray diffraction (XRD) patterns of the results showed that after dissolution the cellulose I (native form), the crystalline structure was completely converted into cellulose II (amorphous) structure, and this was due to the removal of lignin and decrease in cellulose crystallinity. TGA results showed that the regenerated cellulose samples have higher char yields compared to the MCC which is due to the IL remaining in the regenerated cellulose. It was also observed that the addition of the co-solvents decreased the viscosity of the IL mixture, facilitating dissolution of the cellulose that led to additional swelling and reduction of the recalcitrant nature of the cellulose crystalline structure and intermolecular interactions. This led to increased accessibility and dissolution of the cellulose. The findings in this study have the potential to bring ILs closer to applications for biomass technology in particular for an economically viable dissolution method for biomass because ILs have a benefit of being easily separated from the anti-solvent, which provides a simple solution for IL recycle ability and re-use. The novel aspect of this study is: . This is the first study in the South African context to examine the influence of the lignin on the dissolution and regeneration of Eucalyptus sawdust wood and dissolving pulp. / D

Polymer-based piezoelectric and triboelectric generators form the basis of well-known energy harvesting methods that are capable of transforming ambient vibrational energy into electrical energy via electrical polarization changes in a material and contact electrification, respectively. However, the low energy conversion efficiency and limited thermal stability of polymeric materials hinder practical application. While nanostructured polymers and polymer-based nanocomposites have been widely studied to overcome these limitations, the performance improvement has not been satisfactory due to limitations pertaining to long-standing problems associated with polymeric materials; such as low crystallinity of nanostructured polymers, and in the case of nanocomposites, poor dispersion and distribution of nanoparticles in the polymer matrix. In this thesis, novel functional polymeric nanomaterials, for stable and physically robust energy harvesting applications, are proposed by developing advanced nanofabrication methods. The focus is on ferroelectric polymeric nanomaterials, as this class of materials is particularly well-suited for both piezoelectric and triboelectric energy harvesting. The thesis is broadly divided into two parts. The first part focuses on Nylon-11 nanowires grown by a template-wetting method. Nylon-11 was chosen due to its reasonably good ferroelectric properties and high thermal stability, relative to more commonly studied ferroelectric polymers such as polyvinylidene fluoride (PVDF) and polyvinylidene fluoride-trifluoroethylene (P(VDF-TrFE)). However, limitations in thin-film fabrication of Nylon-11 have led to poor control over crystallinity, and thus investigation of this material for practical applications had been mostly discontinued, and its energy harvesting potential never fully realised. The work in this thesis shows that these problems can be overcome by adopting nanoporous template-wetting as a versatile tool to grow Nylon-11 nanowires with controlled crystallinity. Since the template-grown Nylon-11 nanowires exhibit a polarisation without any additional electrical poling process by exploiting the nanoconfinement effect, they have been directly incorporated into nano-piezoelectric generators, exhibiting high temperature stability and excellent fatigue performance. To further enhance the energy harvesting capability of Nylon-11 nanowires, a gas -flow assisted nano-template (GANT) infiltration method has been developed, whereby rapid crystallisation induced by gas-flow leads to the formation of the ferroelectric δʹ-phase. The well-defined crystallisation conditions resulting from the GANT method not only lead to self-polarization but also increases average crystallinity from 29 % to 38 %. δʹ-phase Nylon-11 nanowires introduced into a prototype triboelectric generator are shown to give rise to a six-fold increase in output power density as observed relative to the δʹ-phase film-based device. Interestingly, based on the accumulated understanding of the template-wetting method, Nylon-11, and energy harvesting devices, it was found that thermodynamically stable α-phase Nylon-11 nanowires are most suitable for triboelectric energy generators, but not piezoelectric generators. Notably, definitive dipole alignment of α-phase nanowires is shown to have been achieved for the first time via a novel thermally assisted nano-template infiltration (TANI) method, resulting in exceptionally strong and thermally stable spontaneous polarization, as confirmed by molecular structure simulations. The output power density of a triboelectric generator based on α-phase nanowires is shown to be enhanced by 328 % compared to a δʹ-phase nanowire-based device under the same mechanical excitation. The second part of the thesis presents recent progress on polymer-based multi-layered nanocomposites for energy harvesting applications. To solve the existing issues related to poor dispersion and distribution of nanoparticles in the polymer matrix, a dual aerosol-jet printing method has been developed and applied. As a result, outstanding dispersion and distribution. Furthermore, this method allows precise control of the various physical properties of interest, including the dielectric permittivity. The resulting nanocomposite contributes to an overall enhancement of the device capacitance, which also leads to high-performance triboelectric generators. This thesis therefore presents advances in novel functional polymeric nanomaterials for energy harvesting applications, with improved performance and thermal stability. It further offers insight regarding the long-standing issues in the field of Nylon-11, template-wetting, and polymer-based nanocomposites.

Ce travail s'inscrit dans le cadre d'un projet soutenu par la Région wallonne et a été réalisé en collaboration entre les unités de Chimie Organique et Médicinale (CHOM), de Chimie Structurale et des Mécanismes Réactionnels (CSTR), et de Chimie et Physique des Hauts Polymères (POLY). Il concerne la modification des propriétés du polypropylène (PP) isotactique par mise en œuvre réactive, et plus particulièrement le contrôle de sa cristallinité par l'action d'un composé bromé (N-bromosuccinimide) en présence d'un initiateur de radicaux libres à haute température (entre 180 et 260°C). L'objectif principal de cette étude est de parvenir à identifier et à contrôler les modifications induites au sein des produits, ce qui implique une compréhension fine des mécanismes chimiques intervenant lors de la mise en œuvre réactive du PP. Ces connaissances permettraient en outre de substituer la N-bromosuccinimide (qui génère des sous-produits toxiques et polluants) par un autre additif en vue d'une meilleure valorisation du procédé et des produits. La stratégie repose sur une double approche, basée d'une part sur une étude des divers paramètres qui influencent la réaction sur polymère, et d'autre part sur la synthèse d'un composé modèle du PP : le 2,4,6,8,10-pentaméthylundécane (PMU). Par extrusion réactive du polymère, nous avons obtenu des PP à cristallinité contrôlée (PPCC ; de semi-cristallin à amorphe), dont certains présentent un caractère élastomère marqué. Des études effectuées principalement par analyse thermique et par résonance magnétique nucléaire ont permis de corréler ces propriétés macroscopiques à une microstructure à stéréoblocs isotactiques/atactiques (épimérisation des carbones tertiaires du PP), combinée à la présence de branchements longs (recombinaison de macroradicaux). Par ailleurs, nous avons mis en évidence les différents paramètres susceptibles d'influencer la réaction d'épimérisation du PP. Bien que les informations découlant de ces études nous aient permis de proposer les principaux mécanismes qui entrent en jeu lors de la réaction, seule une étude sur composé modèle peut néanmoins donner accès aux méthodes d'analyses nécessaires à la confirmation de ces mécanismes. Nous avons par conséquent entrepris la synthèse d'un oligomère de propylène pour permettre cette étude sur composé modèle. La synthèse du PMU telle que rapportée dans la littérature s'est avérée plus difficile que prévu, principalement du fait d'un manque de reproductibilité au niveau de l'étape clé. Nous avons donc établi une voie de synthèse originale permettant l'obtention du PMU (mélange de stéréoisomères) avec un rendement global de 45% sur 7 étapes (à l'échelle de plusieurs grammes de produit). En outre, cette voie nous a donné accès au 6-hydroxyméthyl-2,4,8,10-tétraméthylundécane et au 6-p-toluènesulfonyloxyméthyl-2,4,8,10-tétraméthylundécane, pour lesquels des techniques chromatographiques ont permi une séparation des diastéréoisomères. La transposition de ces expériences à plus grande échelle permettra d'envisager l'obtention du (4R,6s,8S)-PMU, en vue de futures études mécanistiques relatives à l'épimérisation du PP de configuration initialement isotactique. / This work is part of a project supported by the Walloon Region, and it was performed in collaboration between the Chimie Organique et Médicinale (CHOM), Chimie Structurale et des Mécanismes Réactionnels (CSTR), and Chimie et Physique des Hauts Polymères (POLY) laboratories. Its object is the modification of the isotactic polypropylene (PP) properties by reactive processing, and more especially the control of PP crystallinity by means of a brominated additive (N-bromosuccinimide) in presence of a free radical initiator at high temperatures (between 180 and 260°C). The main objective of this study is to identify and to control the modifications induced in the products, which implies a fine understanding of the chemical mechanisms occuring during the PP reactive processing. This knowledge would allow us, subsequently, to substitute another additive for the N-bromosuccinimide (which yields toxic and polluting by-products), in order to achieve a better applicability of both the process and the products. The strategy relies on a double approach : on one side, on a study of the various parameters affecting the reaction on the polymer, and on the other side on the synthesis of a model compound of PP : 2,4,6,8,10-pentamethylundecane (PMU). By means of reactive extrusion of the polymer, we obtained controlled crystallinity PP's (from semi-crystalline to amorphous), including some with an elastomeric behaviour. Studies carried out mainly by thermal analysis and nuclear magnetic resonance allowed us to correlate these macroscopic properties to an isotactic/atactic stereoblock microstructure (epimerization of the PP tertiary carbons), combined with the presence of long chain branchings (recombination of macroradicals). Moreover, we highlighted the various parameters that are able to influence the yield of the epimerization reaction. Even if the informations arising from these studies allowed us to propose the main mechanisms involved in the PP modification, only a mechanistic study carried out on a model compound would give us access to the characterization methods required for the confirmation of these mechanisms. We undertook, subsequently, the synthesis of a propene oligomer. The PMU synthesis, as stated in the litterature, revealed itself more difficult than initially foreseen, mainly due to a lack of reproducibility concerning the key step. Therefore we established a new synthesis pathway for the PMU (as a mixture of stereoisomers) with a global yield of 45% over 7 steps (multigram scale). Moreover, this pathway gave us access to 6-hydroxymethyl-2,4,8,10-tetramethylundecane and 6-p-toluenesulfonyloxymethyl-2,4,8,10-tetramethylundecane, for which chromatographic techniques allowed a separation of the diastereoisomers. The transposition of these experiments on a larger scale would allow us to obtain the (4R,6s,8S)-PMU for future mechanistic studies relative to the epimerization reaction of initially isotactic PP.

Dynamic (or 2D) FT-IR spectroscopy in combination withpolarized IR irradiation has been used in this work to studywood polymer orientation and interactions on theultrastructural level in wood fibers in the native state aswell as the effects of different pulping processes. The woodpolymer interactions were studied under both dry and humidconditions. The matrix of lignin and hemicelluloses located between thewell-ordered cellulose fibrils in the wood cell wall of sprucewas here shown to be more highly ordered than has earlier beenrevealed. It was confirmed that glucomannan is orientedparallel to the cellulose fibrils and is highly coupled to it.The lignin was also shown to have a main orientation in thestructure although this is probably not as strong as that ofglucomannan. The orientation of the lignin may derive from thefact that the polysaccharides act as templates during thelignification of the cell wall. This organization implies thatnot only the cellulose but also the lignin and thehemicelluloses have different mechanical properties in thelongitudinal and cross-fiber directions. The ability to gain molecular information on the stresstransfer in polymers with dynamic FT-IR spectroscopy made itpossible to verify experimentally earlier molecularcalculations on the stress transfer within the cellulose chain.It was also possible to show, on the molecular level, thedominant importance of the cellulose fibrils for the stresstransfer in the longitudinal direction of pulp fibers,including lignin-rich mechanical pulp fibers. The glucomannanof softwood fibers was also shown to participate in the stresstransfer in the fiber direction indicating a close associationwith the cellulose, whereas the xylan showed no dynamicresponse. Already under dry conditions, the lignin was shown tohave a more viscoelastic response than the polysaccharidesduring the loading of pulp fibers and it was thus able to moveindependently of the cellulose. The enhanced spectral resolution obtained with dynamic FT-IRspectroscopy made it possible to study the crystalstructure/chain order of cellulose in pulp fibers. Thepossibility of following changes in the relative cellulose Iallomorph composition of pulp fibers was demonstrated for somechemical pulps. Dynamic FT-IR experiments under humid conditions and ofelevated temperatures made it possible to study the softeningof the biopolymers in their native environment. This was alsodemonstrated for some different pulps, and this may be apromising tool for obtaining viscoelastic information on themolecular level in composite systems such as wood fibers. <b>Keywords:</b>cellulose, cooperation, crystallinity, dynamictest, glucomannan, hardwood, holocellulose, humidity, infraredspectroscopy, kraft pulp, lignin, mechanical pulp, orientation,polarised light, softwood, strain, sulphite pulp,viscoelasticity, xylan

Environmental concerns arising from the use of non-degradable plastics have resulted in search for suitable substitutes. The thesis deals with new nanostructured composites based on reinforcement of nanocellulose whiskers in "green" polymers such as xylan. Since the reinforcement filler and the matrix are both biobased and are thereby environmental friendly. Xylan incorporated with cellulose whiskers films provided with improved water and oxygen barrier properties. It appears that the high degree of crystallinity of cellulose whiskers, dense composite structure formed by the whiskers and rigidly hydrogen-bonded cellulose whiskers can cause cellulose whiskers to form integrated matrix which contribute to substantial benefit in the overall reduction of transmission rate. The spectral data obtained for the NCW/xylan nanocomposite films showed that the amount of xylan adsorbed to cellulose increases with the addition of NCW in the matrix. In addition, NMR T2 relaxation experiments studies were conducted to investigate the change in the nature of carbohydrate-water interactions as a result of NCW incorporation. These results facilitated an improved understanding of the mechanisms involved in the superior barrier and mechanical properties of xylan-whisker nanocomposite films. XRD studies show that when a xylan-whisker nanocomposite films is formed the mixing occurs on the atomic scale and NCW loading increases the matrix crystallinity.

This research is directed toward understanding the effect of nanoparticle attributes and polymer morphology on the properties of the nanocomposites with analogous nanoparticle chemistry. In order to develop this understanding, polymer nanocomposites containing calcium phosphate nanoparticles of different specific surface areas and shapes were fabricated and characterized through thermal and thermomechanical techniques. Nanoparticles were synthesized using reverse microemulsion technique. For nanocomposites with different surface area particles, the mobility of amorphous polymer chains was restricted significantly by the presence of particles with an interphase network morphology at higher loadings. Composites fabricated with different crystallinity matrices showed that the dispersion characteristics and reinforcement behavior of nanoparticles were governed by the amount of amorphous polymer fraction available. The study conducted on the effect of nanoparticle shape with near-spherical and nanofiber nanoparticles illustrated that the crystallization kinetics and the final microstructure of the composites was a function of shape of the nanoparticles. The results of this research indicate that nanoparticle geometry and matrix morphology are important parameters to be considered in designing and characterizing the structure-property relationship in polymer nanocomposites.

<p>Dynamic (or 2D) FT-IR spectroscopy in combination withpolarized IR irradiation has been used in this work to studywood polymer orientation and interactions on theultrastructural level in wood fibers in the native state aswell as the effects of different pulping processes. The woodpolymer interactions were studied under both dry and humidconditions.</p><p>The matrix of lignin and hemicelluloses located between thewell-ordered cellulose fibrils in the wood cell wall of sprucewas here shown to be more highly ordered than has earlier beenrevealed. It was confirmed that glucomannan is orientedparallel to the cellulose fibrils and is highly coupled to it.The lignin was also shown to have a main orientation in thestructure although this is probably not as strong as that ofglucomannan. The orientation of the lignin may derive from thefact that the polysaccharides act as templates during thelignification of the cell wall. This organization implies thatnot only the cellulose but also the lignin and thehemicelluloses have different mechanical properties in thelongitudinal and cross-fiber directions.</p><p>The ability to gain molecular information on the stresstransfer in polymers with dynamic FT-IR spectroscopy made itpossible to verify experimentally earlier molecularcalculations on the stress transfer within the cellulose chain.It was also possible to show, on the molecular level, thedominant importance of the cellulose fibrils for the stresstransfer in the longitudinal direction of pulp fibers,including lignin-rich mechanical pulp fibers. The glucomannanof softwood fibers was also shown to participate in the stresstransfer in the fiber direction indicating a close associationwith the cellulose, whereas the xylan showed no dynamicresponse. Already under dry conditions, the lignin was shown tohave a more viscoelastic response than the polysaccharidesduring the loading of pulp fibers and it was thus able to moveindependently of the cellulose.</p><p>The enhanced spectral resolution obtained with dynamic FT-IRspectroscopy made it possible to study the crystalstructure/chain order of cellulose in pulp fibers. Thepossibility of following changes in the relative cellulose Iallomorph composition of pulp fibers was demonstrated for somechemical pulps.</p><p>Dynamic FT-IR experiments under humid conditions and ofelevated temperatures made it possible to study the softeningof the biopolymers in their native environment. This was alsodemonstrated for some different pulps, and this may be apromising tool for obtaining viscoelastic information on themolecular level in composite systems such as wood fibers.</p><p><b>Keywords:</b>cellulose, cooperation, crystallinity, dynamictest, glucomannan, hardwood, holocellulose, humidity, infraredspectroscopy, kraft pulp, lignin, mechanical pulp, orientation,polarised light, softwood, strain, sulphite pulp,viscoelasticity, xylan</p>

Made available in DSpace on 2016-06-02T19:10:02Z (GMT). No. of bitstreams: 1 TeseCL.pdf: 10208729 bytes, checksum: c527b49760e4f73c81deddd8b9282627 (MD5) Previous issue date: 2004-08-12 / Universidade Federal de Minas Gerais / The influence of the injection molding parameters on the morphology and mechanical properties of poly(phenylene sulfide), PPS, and of a 80/20(%wt) blend of PPS/block copolymer styrene-ethylene-butylene-styrene ,SEBS, were evaluated. The injection molding conditions were defined through an experimental design. The lower and upper limits of each variable were set considering the material characteristics and the machine capacity. The software MOLDFLOW® was used to simulate the injection molding process, to define the cooling and holding times, to guarantee the part quality and to obtain the shear rate and bulk temperature profiles at the end of the filling step. For PPS, it was observed that the variables with highest influence on the gradient of crystallinity along the part thickness and on the mechanical properties were melt (Tinj) and mold (Tm) temperatures. For the PPS/SEBS blend, the flow rate (Q), mold temperature and holding pressure (Ph) were the variables with highest influence on the morphology. The aspect ratio of the SEBS particles, dispersed on the PPS matrix, was almost unaffected by the changes of the injection conditions; on the other hand, the mean particle size (caliper length along the major axis) and the value of the dispersion function represented qualitatively well the morphological variations observed for the blend. The artificial neural networks, built with experimental data and trained with the group cross validation method (GCV), predicted with good precision the morphology and the mechanical properties, starting from the injection molding processing conditions, as well as the mechanical properties starting from the morphological aspects. / A influência das variáveis de processamento da moldagem por injeção na morfologia e nas propriedades mecânicas foi avaliada para o poli(sulfeto de p-fenileno), PPS, e para a blenda de PPS com o copolímero em bloco de estireno-etileno-butileno-estireno, SEBS, na concentração em massa 80/20 (PPS/SEBS). A definição das condições de injeção foi feita através de planejamento de experimentos. Os limites inferiores e superiores de cada variável foram definidos levando em consideração as características do material e a capacidade da máquina injetora. O programa computacional MOLDFLOW® foi utilizado para a simulação do processo de injeção para a definição dos tempos de resfriamento e de empacotamento, para garantia da qualidade do moldado e para a obtenção dos perfis de taxa de cisalhamento e de temperatura da massa ao final da etapa de preenchimento. Foi verificado que, no caso do PPS, as variáveis de maior influência no gradiente de cristalinidade ao longo da espessura da peça e nas propriedades mecânicas foram as temperaturas da massa polimérica fundida (Tinj) e do molde (Tm). No caso da blenda PPS/SEBS, a velocidade de injeção ou vazão (Q), a temperatura do molde e a pressão de empacotamento (Ph) foram as variáveis de maior influência na morfologia. A razão de aspecto das partículas de SEBS, dispersas na matriz de PPS, praticamente não foi alterada com a variação das condições de injeção, ao contrário do tamanho médio de partícula e do valor da função dispersão, que pôde representar qualitativamente bem as alterações morfológicas observadas na blenda. As redes neurais construídas a partir dos dados experimentais e treinadas com o método de validação cruzada em grupo (VCG) puderam predizer com boa precisão a morfologia e as propriedades mecânicas do moldado a partir das condições de processamento, bem como as propriedades mecânicas a partir da morfologia. Palavras-chave: morfologia, cristalinidade, blenda, propriedades mecânicas, moldagem por injeção, A influência das variáveis de processamento da moldagem por injeção na morfologia e nas propriedades mecânicas foi avaliada para o poli(sulfeto de p-fenileno), PPS, e para a blenda de PPS com o copolímero em bloco de estireno-etileno-butileno-estireno, SEBS, na concentração em massa 80/20 (PPS/SEBS). A definição das condições de injeção foi feita através de planejamento de experimentos. Os limites inferiores e superiores de cada variável foram definidos levando em consideração as características do material e a capacidade da máquina injetora. O programa computacional MOLDFLOW® foi utilizado para a simulação do processo de injeção para a definição dos tempos de resfriamento e de empacotamento, para garantia da qualidade do moldado e para a obtenção dos perfis de taxa de cisalhamento e de temperatura da massa ao final da etapa de preenchimento. Foi verificado que, no caso do PPS, as variáveis de maior influência no gradiente de cristalinidade ao longo da espessura da peça e nas propriedades mecânicas foram as temperaturas da massa polimérica fundida (Tinj) e do molde (Tm). No caso da blenda PPS/SEBS, a velocidade de injeção ou vazão (Q), a temperatura do molde e a pressão de empacotamento (Ph) foram as variáveis de maior influência na morfologia. A razão de aspecto das partículas de SEBS, dispersas na matriz de PPS, praticamente não foi alterada com a variação das condições de injeção, ao contrário do tamanho médio de partícula e do valor da função dispersão, que pôde representar qualitativamente bem as alterações morfológicas observadas na blenda. As redes neurais construídas a partir dos dados experimentais e treinadas com o método de validação cruzada em grupo (VCG) puderam predizer com boa precisão a morfologia e as propriedades mecânicas do moldado a partir das condições de processamento, bem como as propriedades mecânicas a partir da morfologia.