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Predicting the replication fidelity of injection molded solid polymer microneedles / Tim Evens in INTERNATIONAL POLYMER PROCESSING, Vol. 37, N° 3 (2022)  

[article]  inINTERNATIONAL POLYMER PROCESSING > Vol. 37, N° 3 (2022) . - p. 237-254 Titre : Predicting the replication fidelity of injection molded solid polymer microneedles Type de document : texte imprimé Auteurs : Tim Evens, Auteur ; Sylvie Castagne, Auteur ; David Seveno, Auteur ; Albert Van Bael, Auteur Année de publication : 2022 Article en page(s) : p. 237-254 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Matières plastiques -- Moulage par injection Micro-aiguilles Polycarbonates Polypropylène Prévision, Théorie de la Réplication (technologie) Simulation par ordinateur Index. décimale : 668.9 Polymères Résumé : Microneedles are sharp microscopic features, which can be used for drug or vaccine delivery in a minimally invasive way. Recently, we developed a method to produce polymer microneedles using laser ablated molds in an injection molding process. At this moment, extensive injection molding experiments are needed to investigate the replication fidelity. Accurate predictions of the injection molding process would eliminate these costly and time expensive experiments. In this study, we evaluated the replication fidelity of solid polymer microneedles using numerical simulations and compared the results to injection molding experiments. This study was performed for different sizes of microneedles, different thermoplastics (polypropylene and polycarbonate) and different mold materials (tool steel, copper alloy and aluminium alloy). Moreover, different processing conditions and different locations of the microneedles on the macroscopic part were considered. A good correlation with experimental findings was achieved by optimizing the heat transfer coefficient between the polymer and the mold, while using a multiscale mesh with a sufficient number of mesh elements. Optimal heat transfer coefficients between 10,000 and 55,000 W/m2 K were found for the different combinations of polymer and mold materials, which resulted in an accuracy of the simulated microneedle replication fidelity between 94.5 and 97.0%. Note de contenu : - MATERIALS AND METHODS : Thermoplastic polymers - Mold insert - Injection molding product - Injection molding experiments - INJECTION MOLDING SIMULATIONS SETTINGS : It can be assumed that the macroscopic flow - Simulation parameters in Moldex3D - Mesh convergence study using multi-scale meshing - Heat transfer coefficient - Replication fidelity in function of the location of the microfeatures - Replication fidelity in function of the injection molding parameter - Replication fidelity in function of the mold material - RESULTS AND DISCUSSION : Macroscopic flow - Mesh convergence study - Effect of the heat transfer coefficient - Replication fidelity in function of the location of the microfeatures - Replication fidelity in function of the injection molding parameters - Replication fidelity in function of the mold material - Table 1 : Main properties of the thermoplastics based on material datasheets and the Moldex3D 2020 material database - Table 2 : Thermal properties of the different mold materials based on material datasheets - Table 3 : Injection molding process parameters for the two thermoplastic materials - Table 4 : Default and adapted simulation parameters in Moldex3D - Table 5 : Adapted injection molding process parameters for the two thermoplastic materials - Table 6 : Heat transfer coefficients, corresponding to a minimal average absolute deviation between the simulated and experimentally determined replication fidelity, for the PP and PC in combination with the tool steel, the aluminium alloy and the copper alloy mold insert DOI : https://doi.org/10.1515/ipp-2021-4207 En ligne : https://drive.google.com/file/d/1oNumrisvhCE-7j_vpdYOWG6Ed6AmPXcr/view?usp=shari [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=37904 [article]

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An experimental study on the role of manufacturing parameters on the dry sliding wear performance of additively manufactured PETG / Berkay Ergene in INTERNATIONAL POLYMER PROCESSING, Vol. 37, N° 3 (2022)  

[article]  inINTERNATIONAL POLYMER PROCESSING > Vol. 37, N° 3 (2022) . - p. 255-270 Titre : An experimental study on the role of manufacturing parameters on the dry sliding wear performance of additively manufactured PETG Type de document : texte imprimé Auteurs : Berkay Ergene, Auteur ; Cagin Bolat, Auteur Année de publication : 2022 Article en page(s) : p. 255-270 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Frottements (mécanique) Impression tridimensionnelle Matériaux -- Epaisseur Mesure Polyéthylène téréphtalate glycol Taux de remplissage (technologie) Tribologie (technologie) Usure (mécanique) Index. décimale : 668.9 Polymères Résumé : Additive manufacturing (AM) is a versatile and promising method for rapid prototyping and advanced design applications. Owing to its unique potential for fast production rates, and capacity of creating complex shapes, the number of researches on AM techniques have increased day by day in the technical literature. In this work, contrary to common literature efforts focused on mechanical properties, friction and wear behaviors of additively manufactured PETG samples were analyzed experimentally. As a methodology, fused filament fabrication (FFF) was selected. In order to explore the influence of manufacturing factors on wear properties, layer thickness (0.1, 0.2, and 0.3 mm), infill rate (40, 60, 80, and 100%), and building direction (vertical and horizontal) were changed. Before the friction tests, dimensional accuracy, hardness, and surface roughness measurements were conducted to interpret better the wear results. In addition, macroscopic and microscopic inspections were performed to determine the correct reason behind the deformation. From the data collected during the tests, there was a positive interaction between volume loss and layer thickness. Besides, there was no direct interaction between infill rate/building direction and coefficient of friction. In comparison with vertically built samples, horizontally built samples were subjected to more plastic deformation, and their worn surfaces were severely damaged. Note de contenu : - MATERIAL AND METHODOLOGY : Filament material and manufacturing - Dimensional accuracy measurements - Hardness measurements - Surface roughness measurements - Wear test procedure - RESULTS AND DISCUSSION : Dimensional accuracy - Hardness - Surface roughness - Tribological properties - Wear mechanisms - Table 1 : Material properties of PETG filament - Table 2 : 3D printing process parameters - Table 3 : The average accuracy percentage obtained from dimensional measurements of cylindrical sample DOI : https://doi.org/10.1515/ipp-2021-0015 En ligne : https://drive.google.com/file/d/12N5Uiq-s3wa6d0OOg1JqCYh_QpvMA-b5/view?usp=shari [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=37905 [article]

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Effect of expansion temperature on the properties of expanded graphite and modified linear low density polyethylene / Xiuyan Pang in INTERNATIONAL POLYMER PROCESSING, Vol. 37, N° 3 (2022)  

[article]  inINTERNATIONAL POLYMER PROCESSING > Vol. 37, N° 3 (2022) . - p. 271-286 Titre : Effect of expansion temperature on the properties of expanded graphite and modified linear low density polyethylene Type de document : texte imprimé Auteurs : Xiuyan Pang, Auteur ; Wenyu Zhang, Auteur ; Yafang Meng, Auteur ; Meifang Ma, Auteur ; Jianzhong Xu, Auteur Année de publication : 2022 Article en page(s) : p. 271-286 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Caractérisation Combustion Composites -- Propriétés mécaniques Formulation (Génie chimique) Graphite Ignifugeants Composé chimique utilisé pour réduire l'inflammabilité. Il peut être incorporé au produit durant sa fabrication ou appliqué ultérieurement à sa surface. Matières plastiques -- Additifs Mesure Polyéthylène basse densité linéaire Thermocinétique Index. décimale : 668.9 Polymères Résumé : To study the influence of expansion temperature on the properties of expanded graphite (EBG), EBG300, EBG600, and EBG900 were prepared by heating expandable graphite (EG) at 300, 600, and 900 °C, respectively. Furthermore, the influence of these EBGs on the combustion performance and physical-mechanical properties of linear low density polyethylene (LLDPE) were investigated. The expansion volumes of EBG300, EBG600, and EBG900 increase with the rise of temperature, and a four-stage ordered structure of “graphite worm” gradually forms. The thermal stability increases gradually for EBG300, EBG600, and EBG900. On the contrary, the thermal conductivity decreases in sequence. However, the incorporation of EBG900 promotes the formation of a continuous network structure and makes the modified LLDPE to present the best heat transmission. The addition of 30 wt% of these EBGs significantly improves LLDPE’s flame retardancy and high-temperature thermal stability. The total heat release, the peak value of heat release rate, and the fire growth index of 70LLDPE/30EBG300 reduce by 69, 91, and 87% respectively, while the effective fire performance index improves seven times. The addition of these additives reduces the tensile strength and elongation at break, the larger the EBG size, the more obvious the effect. Note de contenu : - EXPERIMENTAL : Raw materials - Sample preparation - Measurements and characterization - RESULTS AND DISCUSSION : Influence of expansion temperature on EBG properties - Influence of EG, EBG300, EBG600, and EBG900 on LLDPE properties - Table 1 : Formulation of the modified LLDPE composites - Table 2 : Thermal conductivity of EG, EBG300, EBG600, and EBG900 - Table 3 : Density and thermal conductivity of the LLDPE composites - Table 4 : LOI, UL-94 level, EFF, and SE - Table 5 : CCT results for the LLDPE composites - Table 6 : TG/DTG data for the LLDPE composites DOI : https://doi.org/10.1515/ipp-2022-0003 En ligne : https://drive.google.com/file/d/1N7jAae7A2BdgIJsnfodxCA9GoerFh_GO/view?usp=shari [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=37906 [article]

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Thermal, morphological, rheological and deformation under mechanical loading analyses of recycled polyethylene terephthalates / Kivanc Bakir in INTERNATIONAL POLYMER PROCESSING, Vol. 37, N° 3 (2022)  

[article]  inINTERNATIONAL POLYMER PROCESSING > Vol. 37, N° 3 (2022) . - p. 287-302 Titre : Thermal, morphological, rheological and deformation under mechanical loading analyses of recycled polyethylene terephthalates Type de document : texte imprimé Auteurs : Kivanc Bakir, Auteur ; Deniz Aydemir, Auteur ; Timucin Bardak, Auteur ; Murat Emre Kartal, Auteur Année de publication : 2022 Article en page(s) : p. 287-302 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Analyse thermique Déformations (mécanique) Eléments finis, Méthode des Imagerie numérique Matières plastiques -- Propriétés thermiques Matières plastiques -- Recyclage Morphologie (matériaux) Polyéthylène téréphtalate Rhéologie Index. décimale : 668.4 Plastiques, vinyles Résumé : This study aims at determining the mechanical deformation behavior of recycled poly (ethylene terephthalate) (r-PET) with digital image correlation (DIC) and finite element method (FEM), and to investigate the morphological, thermal, and rheological properties of r-PETs. Waste bottles were collected in trash bins and granulated with a cutter. Neat PET (n-PET) was also was used to determine accurately the changes in the properties of r-PET. PET test samples were obtained by injection molding at 260, 265, 270, and 275 °C. DIC and FEM were conducted to detect the deformation behavior of the PETs under mechanical loading. The data showed that the behavior of n-PETs and r-PETs were similar, and the stress distribution was found to densify in various areas for both PETs. The mechanical properties generally increased with increasing processing temperature, the best mechanical properties being obtained for thPETs processed at 275 °C. Scanning electron microscopy (SEM) analysis showed that the morphology of all the PETs were similar. Thermal stability was also found to be similar. The rheological moduli of n-PET processed at 260 °C were the highest, while processing r-PET at 275 °C improved its rheological properties. Note de contenu : - MATERIALS AND METHODS : Materials - Preparation of PET test samples - Methods - RESULTS AND DISCUSSION : Mechanical properties of the PETs and the deformation analysis with DIC and FEM under mechanical testing - Morphological analysis - Thermal properties - Rheological properties - Table 1 : TGA Data for n-PET and r-PET processed at different temperatures DOI : https://doi.org/10.1515/ipp-2021-4165 En ligne : https://drive.google.com/file/d/13qTzJI31__flej8f48rzLT0zepAVN-Da/view?usp=shari [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=37907 [article]

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Mung bean protein films incorporated with cumin essential oil : development and characterization / Majid Mojoodi in INTERNATIONAL POLYMER PROCESSING, Vol. 37, N° 3 (2022)  

[article]  inINTERNATIONAL POLYMER PROCESSING > Vol. 37, N° 3 (2022) . - p. 303-315 Titre : Mung bean protein films incorporated with cumin essential oil : development and characterization Type de document : texte imprimé Auteurs : Majid Mojoodi, Auteur ; Moloud Nourani, Auteur Année de publication : 2022 Article en page(s) : p. 303-315 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Aliments -- Conservation Aliments -- Emballages Antioxydants Biodégradation Couches minces -- Propriétés physiques Couches minces -- Propriétés thermiques Cumin et constituants Huiles essentielles Matériaux -- Biodégradation Protéines végétales Index. décimale : 668.4 Plastiques, vinyles Résumé : Biodegradable films based on mung bean protein (1, 3 and 5%) incorporated with cumin essential oil (EO) (0, 0.25 and 0.5 ml/g protein) were developed. Adding cumin oil and increasing the protein content enhanced the thickness, tensile strength and yellowness. Films incorporated with EO exhibited less water vapor permeability and water solubility, as compared to the control films. A higher antioxidant activity was also obtained by increasing the EO and protein ratios. Films with higher levels of protein displayed lower thermal stability with a lower degradation temperature, as suggested by thermo-gravimetric analyses. In addition, the incorporation of EO reduced thermal stability, as confirmed by the higher weight loss and lower degradation temperature. Furthermore, mung bean protein films containing 0.5 ml cumin oil/g protein had suitable physical characteristics, antioxidant activities, water barrier properties and thermal stability; thus, they can be used as appropriate biodegradable packaging materials for food preservation. Note de contenu : - MATERIALS AND METHODS : Materials - Protein extraction - Film preparation - Characterization of the films - Statistical analysis - RESULTS AND DISCUSSION : Color properties - Thickness, water solubility and WVP - Antioxidant activity and total phenolic content - Mechanical properties - Microstructure - Thermo-gravimetric analysis (TGA) - Table 1: Color parameters of mung bean protein-cumin essential oil films (mean ± standard deviation) - Table 2 : Physical properties of mung bean protein-cumin essential oil films (mean ± standard deviation - Table 3 : Antioxidant properties of mung bean protein-cumin essential oil films at different EO/P (mean ± standard deviation) (for each row the average values of antioxidant properties at protein concentrations of 1, 3 and 5% has been presented - Table 4 : Antioxidant properties of mung bean protein-cumin essential oil films at different protein concentrations (mean ± standard deviation) (for each row the average values of antioxidant properties at EO/P of 0, 0.25 and 0.5 ml/g has been presented) DOI : https://doi.org/10.1515/ipp-2021-4213 En ligne : https://drive.google.com/file/d/1ofLBG68p1nSscvTEdgbE5J-OdClH-umr/view?usp=shari [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=37908 [article]

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Influence of ammonium octamolybdate on flame retardancy and smoke suppression of PVC matrix flame retardant composites / Jianlin Xu in INTERNATIONAL POLYMER PROCESSING, Vol. 37, N° 3 (2022)  

[article]  inINTERNATIONAL POLYMER PROCESSING > Vol. 37, N° 3 (2022) . - p. 316-328 Titre : Influence of ammonium octamolybdate on flame retardancy and smoke suppression of PVC matrix flame retardant composites Type de document : texte imprimé Auteurs : Jianlin Xu, Auteur ; Chengsi Li, Auteur ; Shibo Ren, Auteur ; Lei Niu, Auteur ; Qingwen Bai, Auteur ; Xiang Li, Auteur Année de publication : 2022 Article en page(s) : p. 316-328 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Anti-fumée Caractérisation Chlorure de polyvinyle Ignifugeants Composé chimique utilisé pour réduire l'inflammabilité. Il peut être incorporé au produit durant sa fabrication ou appliqué ultérieurement à sa surface. Matières plastiques -- Additifs Nanoparticules Octamolybdate d'ammonium Oxydes d'antimoine Le trioxyde d’antimoine, également appelé trioxyde de diantimoine ou oxyde d’antimoine(III), est un composé inorganique de formule Sb2O3. Il s’agit d’un oxyde d'antimoine se présentant au laboratoire sous la forme d’une poudre blanche, sa forme minérale étant la sénarmontite (cristaux cubiques incolores) ou la valentinite (cristaux orthorhombiques blancs). La sénarmontite, stable à température ordinaire, se transforme à 570 °C en valentinite, métastable en dessous de cette température. - Écotoxicologie : En 2022, alors que les mécanismes de toxicité aquatique du Sb sont encore très mal compris, celle de la toxicité moléculaire du Sb(III) l'est plus encore, mais fait l'objet de quelques étude - Utilisations : Il est utilisé comme agent de synergie avec des composés halogénés pour l'ignifugation5 des polymères et textiles ; opacifiant pour verres, céramiques et émaux ; pigment pour peintures et catalyseur chimique. Index. décimale : 668.4 Plastiques, vinyles Résumé : In order to improve the flame retardancy and smoke suppression of polyvinyl chloride (PVC), ammonium octamolybdate (AOM)/nano-antimony trioxide (nano-Sb2O3)/dioctyl Phthalate (DOP)/PVC composites were prepared by high energy ball milling and melt blending methods using AOM as the smoke suppressant. The effects of AOM on the flame retardancy and smoke suppression of the PVC composites were studied by means of vertical burning tests (UL-94), limiting oxygen index (LOI), thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and cone calorimetry (CCT). The results showed that the flame retardancy of PVC composites containing AOM was improved, namely the UL-94 grade of the composites reached the V-0 grade and the LOI increased from 22.3% to 30.6%, whilst the heat release rate (HRR), total heat release (THR), smoke production rate (SPR), total smoke production (TSR) and smoke factor (SF) decreased significantly. In addition, AOM could promote the dehydrochlorination reaction of the PVC composites at lower temperature, resulting in more compact and continuous char residues. Therefore, AOM is an effective smoke suppressant and has a good synergistic flame retardant effect with nano-Sb2O3 in flame retardant PVC matrix composites. Note de contenu : - EXPERIMENTAL : Materials - Samples preparation - Characterization - RESULTS AND DISCUSSION : Vertical burning properties (UL-94) and limiting oxygen index (LOI) - Thermogravimetric analysis (TGA) - Morphology of the char residue - Cone calorimeter test - Table 1 : Compositions of experimental samples (mass fraction, wt %) - Table 2 : LOI and UL-94 test result of pure PVC and its composites - Table 3 : Parameter of TGA of pure PVC and its composites - Table 4 : Cone calorimeter results of pure PVC and its composites DOI : https://doi.org/10.1515/ipp-2022-0007 En ligne : https://drive.google.com/file/d/1hqidh4_4IS7Nhp8MEZbweMNePLFgtbEp/view?usp=shari [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=37909 [article]

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Influence of surface modification on thermal, adhesive properties and impact behavior of TPU films for laminated glass / Chenxing Zhang in INTERNATIONAL POLYMER PROCESSING, Vol. 37, N° 3 (2022)  

[article]  inINTERNATIONAL POLYMER PROCESSING > Vol. 37, N° 3 (2022) . - p. 329-337 Titre : Influence of surface modification on thermal, adhesive properties and impact behavior of TPU films for laminated glass Type de document : texte imprimé Auteurs : Chenxing Zhang, Auteur ; Hongwu Wu, Auteur ; Liangfeng Xu, Auteur ; Mingyuan Ren, Auteur Année de publication : 2022 Article en page(s) : p. 329-337 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Adhésion Caractérisation Essais d'adhésion Essais de résilience Essais dynamiques Films adhésifs Films plastiques Films plastiques -- Propriétés mécaniques Polyuréthanes Stabilité thermique Traîtements de surface Verre -- Revêtements Index. décimale : 668.4 Plastiques, vinyles Résumé : The poor adhesion of TPU films limits their extensive application in lightweight laminated glass (LLG). A simple and effective method is reported in this paper to obtain modified TPU films by silane coupling agent (SCA) treatment. The polar groups (such as urethane groups, carboxyl groups, etc.) on the surface of TPU films reacted chemically with the reactive groups of SCA. Meanwhile, hydrogen bonds were formed between the silicon hydroxyl groups generated by the hydrolysis of SCA. Therefore, the adhesivity and thermal stability of TPU films were improved. Moreover, the surface of TPU films became rough after modification, hence the interfacial bonding area between TPU film and glass increased, which furthered the bonding effect of TPU film with glass plate. Compared with unmodified TPU films, the tensile shear bond strength (TSBS) of modified TPU films increased by nearly 28%, and the initial decomposition temperature increased from 277 °C to a maximum of 295.3 °C. The impact resistance of LLG was significantly improved due to the improvement of the adhesivity of TPU film. Note de contenu : - EXPERIMENTAL : Materials and instruments - Preparation of TPU film - Surface modification of TPU film - Adhesion test and sample preparation - Impact test and sample preparation - Characterization of modified TPU film - RESULTS AND DISCUSSION : FT-IR analysis - Thermogravimetric analysis - SEM microstructure of TPU film - Adhesive properties of TPU film - Impact properties of LLG - Table 1 : Surface modified TPU film samples. A1, A2 and A3 represent hydrolysis time of 2h, 4h and 6h, respectively. B1, B2 and B3 represent ultrasonic treatment time of 2 min, 4min and 6min, respectively - Table 2 : Different decomposition temperature of modified TPU film DOI : https://doi.org/10.1515/ipp-2022-0001 En ligne : https://drive.google.com/file/d/159a_u_N73b5qCKhSShmLt4x1sqZ-mc3k/view?usp=shari [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=37910 [article]

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