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PP composites notched Izod impact strength variations as a function of treated and untreated kaolin concentration.
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The effects of kaolin content and treatments on the thermal and mechanical properties and on the degradation of polypropylene were examined using mechanical tests, differential scanning calorimetry (DSC), and thermogravimetry (TGA). The weak interactions filler/matrix have been reinforced using a modification with urea then with an ammonium salt an...
Citations
... It has been reported that the addition of kaolinite particles alone in HDPE favors a restriction in the mobility of the crystallizable chains, leading to limited lamellar growth along the crystalline side, which leads to a smaller phase crystalline and reduced crystallinity. 53 In contrast, the composite reinforced only with short fibers showed a higher rate of crystallinity, which could be explained by the fact that the fibers provide points of nucleation that accelerate the degree of crystallinity and tend to make the structure crystalline more compact. 54 Overall, the hybrids exhibited high crystallinity, high crystallization temperature, and negligible melting temperature, which well correlated with tensile properties particularly tensile strength and high Young's modulus. ...
This study developed sustainable, cost-effective hybrid composites using high-density polyethylene (HDPE) reinforced with kaolinite particles (KP) and alfa short fibers (ASF) in varying volume fractions (15/0, 10/5, 7.5/7.5, 5/10, 0/15). Injection-molded composites were analyzed for mechanical, thermal, and rheological properties, revealing significant improvements in Young’s modulus (up to 61.60%) with KP and ASF additions. Hybrid composites (7.5:7.5 and 10:5) showed superior elasticity, while the 5:10 formulation achieved the highest storage modulus of 1874 MPa, outperforming pure HDPE (1035 MPa). Thermal analysis indicated stable KP-rich composites and progressive crystallization disruption with increasing filler content. To align experimental and theoretical results, the Young’s modulus for KP and ASF was estimated at 5000 MPa and 8500 MPa, respectively. The optimal 7.5:7.5 hybrid offered balanced mechanical and thermal performance with enhanced elasticity and reduced energy consumption during processing, demonstrating the potential of these hybrids as renewable, sustainable materials for automotive, construction, and sports applications.
... Furthermore, the band observed at 1637 cm -1 is characteristic of the vibration of the H-O-H bond of water adsorbed on the surface of the ore. The intense band detected between 1400 and 800 cm -1 and centered around 1046 cm -1 is attributed to the vibration of the Si-O bond of the Si-O-Si group, while the one located at 797 cm -1 corresponds to the vibrations of deformation of the Si-O bond of the Si-O-Al group[42][43]. FTIR spectra of entreated perlite and perlite treated by silane ...
In this work, it was proposed to replace the conventional reinforcement of the unsaturated polyester resin by a mineral, from a siliceous volcanic rock of volcanic nature, perlite. UPR/perlite composites with different proportions of phase components (from 1% to 5% of powder mass part). We used unsaturated polyester resin (UPR) as well as the hardener cobalt octoate and treated and untreated perlite of different dimensions (greater than 60µm, and less than 60µm). The composites were prepared by the contact molding process. The composite plates are hardened for 24 hours at room temperature then placed in an oven for 15 hours at 50°C to undergo post-curing. The composites obtained were subjected to different characterization techniques, namely rheological tests (dynamic mechanical analysis (DMA)), thermal tests (differential calorimetric analysis (DSC)) and Thermogravimetric analysis (ATG) and structural characterization by Fourier transform infrared (FTIR). The DMA measurements showed that the UPR/perlite composites with untreated filler presented conservation modules higher than that of the resin without perlite for the rates of 3% and 4%, while for the composites with treated filler, that at 3% of perlite shown the highest modulus along the glassy zone. Also, the glass transition temperature of the UPR resin was not affected by the addition of perlite. The decrease in intensity at mid-height of the tan δ peaks allowed deducing the existence of a fairly strong UPR/perlite interface. DSC thermograms showed that the exothermic peak is shifted to higher temperatures, due to a delay in the curing reaction caused by the presence of the perlite particles. This study concluded that the perlite enhances the properties of composites.
... However, the improvement of properties at the rupture for PP/TK composites could be owed to the contribution of the grafted alkyl chain in a better interlocking between the kaolinite particles and the PP matrix which might enhance the adhesion at the interfacial zone to guarantee a more efficient stress transfer through the matrix via the kaolin solid particles. Correspondingly, Guessoum et al. [41] concluded that mineral fillers greatly influence the fracture behaviour of composite materials and noticed a significant decrease in deformation at break from 600% for neat PP to 60% and 27% for the composites with 5 phr of untreated and alkylammonium-treated kaolin, respectively. Figure 9 representing the variations in impact resistance of PP/UK and PP/TK composites display a marked decrease in the resilience of both composites after the incorporation of the clay. ...
To develop charge/matrix interactions and improve the rheological, mechanical, and morphological performances of the matrix polypropylene, PP/kaolinite composites were prepared using the melt intercalation method at 190 °C. The rheological and mechanical properties of polypropylene/kaolin composites have been evaluated at various concentrations of untreated and/or treated kaolin. It was shown that the melt flow index (MFI) varies visibly but slightly compared to that of the matrix with increasing kaolin content. Furthermore, when the kaolin loading is enhanced, the apparent shear viscosity ( η app ) of the composites increases compared to the matrix and decreases with the increase in the shear rate ( γ app ). Also, while the shear stress ( τ app ) is reduced, the flow curve shifts upwards with increasing the kaolin concentration. The systems obeyed the power-law model in shear stress-shear rate variations and were shear thinning as power-law index ( n ) values increased with kaolin content. Moreover, the mechanical properties of the obtained composites were significantly affected by the dispersion of the filler into the matrix and by the weak interactions at the interface PP/kaolinite. SEM micrographs show a poor dispersion of the nanoclay within the polypropylene matrix and the formation of agglomerates with different sizes.
... Several works [17][18][19][20][21][22] studied the effects of kaolinite functionalization on the properties of polymers based nanocomposites have been reported too. Guessoum et al. 23 noticed significant improvements in mechanical properties and thermal stability with a decrease of crystallization temperature of PP/modified kaolin composites. Alternatively, surface modification of kaolin with diethylene triaminepentaacetic acid (DTPA) efficiently improves the compatibility between PP and kaolin leading to a higher melt flow index, tensile, impact, and bending strength, respectively; this composite could completely meet the requirements of home appliances, automotive, machinery, construction, and other areas as recently reported by Yao et al. 24 Morphological examination showed also an indication for an eventually intercalation of PP/kaolin composite in presence of maleic anhydride (MA) and dicumyl peroxide (DCP) as estimated by Degassi et al. 25 In addition, calcined kaolin at 800°C presents better mechanical properties with low density polyethylene (LDPE)/kaolin composite. ...
... The band at 3668 cm À1 is indistinguishable indicating that KT is less order than KS. 23 In fact, the calcination causes the coordination change of the alumina atoms of the octahedral layer and kaolin is transformed into metakaolin, leading to the destruction of the kaolin network. 35 A decrease in the intensity of the characteristic hydroxyls bands is observed especially for silane-treated kaolin (KTTS) and to a lesser extent for KS treated with silane (KSTS). ...
... 42 This could be due to the fact that the silane interacted with the kaolinite hydroxyls groups present at the edges and/or on the surface of the clay particles and not with those situated in the interlayer space. 23,43 Gardolinski et al. 44 reported that the very low cation exchange capacity of kaolinite and a small low specific surface area resulting from the cohesion between the layers give a low adsorption capacity of the organic modifiers. After calcination of KS and KT at 600°C during 3 h, characteristic peaks for kaolinite (22 12,35 and 24,92) disappear due to the loss of bound water and the deterioration of its crystal structure thus creating additional surface defects. ...
The purpose of this study is to investigate the incorporation effect of kaolin clay on the mechanical and thermal properties of PP/kaolin composites. Its performance is studied as a function of powder content in the different particle size. To improve the dispersion of the mineral clay and the interfacial interactions between matrix and filler, maleic anhydride grafted polypropylene (PP-g-MA) was used as a compatibilizer. Also, the filler surface was modified with a silane-coupling agent (hexadecyltrimethoxysilane). The change of the kaolin structure into metakaolin by calcination was carried at 600°C. The results show that silane modified kaolin leads to a better dispersion and to a better mechanical and thermal properties. However, addition of untreated kaolin increases E− modulus of about 32 at 5% wt content. Elongation at break was also enhanced in the presence of calcined and silane modified kaolin as compared to untreated composites. Thermal stability was found to increase with 2.5% of compatibilizer in PP/kaolin composites.
... This indicates that aluminium silicate dihydrate microparticles initiate the mobility of the molecular chains of PP by acting as a heterogeneous nucleation center through lowering the free energy barrier for crystallites formation as reported in the studies of Guessoum et al. (30) and Luyt et al. (31). As the crystallization speed of PP is faster than the extruding process, the introduced microparticles in PP increase the crystallization temperature, which contributes to the reduction of the warping effect. ...
... The rising of the surrounding temperature in the printing chamber through covering the 3D printer open spaces with thick fabrics and papers helps to prevent warpage and improve the strength of the fused deposited samples. The finding of others researchers (26,27,30) also confirms that higher printing chamber temperature leads to fewer occurrences of temperature fluctuation and slower cooldown of the printed samples, which results in less residual stresses and a lower degree of shrinkage. The mathematical model proposed by Wang et al. (32), similarly, approves that the higher temperature of printing chambers results in a reduced amount of warpage. ...
Polypropylene (PP) undergoes fast crystallization
and resulting in rigorous shrinkage when it is subjected
to high temperature likewise of the fused deposition
modeling (FDM) process. This research study focuses
on the investigation of the processing parameters and
factors that decrease the warpage of PP during the FDM
process. Aluminium silicate dihydrate (K) microparticles
of different ratios were melt blended with PP by a twinscrew
extruder, and filaments of about 1.7mm diameter
were extruded in a single screw extruder. Then, the
extruded filaments were used to fabricate the dumbbells
structure through the FDM process. The effects of optimizing
the fused deposition temperature, coating the
chamber with thick papers/fabrics, and coating a printer
bed with PP material were also investigated in this study.
Scanning and transmission electron microscopy, differential
scanning calorimetry, melt flow, and mechanical
properties testing instruments are used to analyze themicroparticles
dispersion, crystallization, flow, and mechanical
properties of resulting samples. Uniformly dispersed filler
and increased printing chamber temperature result in an
increase of crystallization temperature and improve the
dimensional accuracy of fused deposited specimens. The
fused deposited PP-K10 wt% composite showed an improvement
of up to 32% in tensile modulus compared to the
neat PP.
... Experimental results showed that the diameter and pore volume were expanded after modification, which was beneficial to improve adsorption capacity. Guessoum et al. [15] has modified the surface of kaolin by intercalation method using urea then with an ammonium salt and a surface treatment with a silane coupling agent. Then modified and unmodified kaolin were applied as inorganic fillers that are used to improve polypropylene (PP) properties. ...
... The new (2θ) reflections and the expansion of XRD patterns indicated that the intercalation of urea was able to deform hydrogen bonds of the hydroxyl group in the lattice structure of kaolin, and provide a new hydrogen bond structures from Amina group which expanded the basal spacing of intercalated kaolin and make the characteristic of kaolin more swellable [16]. It as described before [15], the basal spacing of the crystal lattice layer of kaolin has been increased by urea intercalation, this formation allowed to provide the expanded basal spacing for cation exchange in the interlayer of kaolin. Figure 1(c) shows the XRD pattern of modified kaolin with the intercalation and exfoliation process (KIE). ...
... Modified physical properties of kaolin for reinforcing filler in the construction industry have been successfully prepared by the intercalation method and combination of the intercalation-exfoliation method. The XRD analysis indicated that the basal spacing of kaolin expanded from 7.17 to 10.76 (KI) and 10 15.29 to 20.43 (KI) and 35.09 % (KIE), which implies successful intercalation of the urea in the interlayer of kaolin. The SEM analysis showed that kaolin has particle stacks that were slightly distantly spaced and few kaolin particles were transformed into smaller sizes after the modification process. ...
The intercalation method and combination of the intercalation-exfoliation method were applied to modify kaolin. The intercalation process was prepared using urea 60 % as an intercalated agent and the exfoliation process was carried out by ultrasonication. The samples were characterized by X-ray diffraction (XRD), X-Ray Fluorescence (XRF), scanning electron microscope (SEM), and particle size analysis (PSA). Experimental results showed that the physical properties of kaolin significantly improved after modification. This was indicated by the increasing interlayer spacing of modified kaolin, which was confirmed by SEM and XRD analysis. Based on XRF analysis, the loss on ignition value increased after kaolin modification, suggesting that the urea had successfully intercalated into the kaolin interlayer. Kaolin modification with intercalation method produced the most significant physical properties improvement, which increased surface area from 2508.607 to 27297.990 cm2/g and decreased particle size average from 41.535 to 13.836 μm and had surface area close to illite clay.
... Experimental results showed that the diameter and pore volume were expanded after modification, which was beneficial to improve adsorption capacity. Guessoum et al. [15] has modified the surface of kaolin by intercalation method using urea then with an ammonium salt and a surface treatment with a silane coupling agent. Then modified and unmodified kaolin were applied as inorganic fillers that are used to improve polypropylene (PP) properties. ...
... The new (2θ) reflections and the expansion of XRD patterns indicated that the intercalation of urea was able to deform hydrogen bonds of the hydroxyl group in the lattice structure of kaolin, and provide a new hydrogen bond structures from Amina group which expanded the basal spacing of intercalated kaolin and make the characteristic of kaolin more swellable [16]. It as described before [15], the basal spacing of the crystal lattice layer of kaolin has been increased by urea intercalation, this formation allowed to provide the expanded basal spacing for cation exchange in the interlayer of kaolin. Figure 1(c) shows the XRD pattern of modified kaolin with the intercalation and exfoliation process (KIE). ...
... Modified physical properties of kaolin for reinforcing filler in the construction industry have been successfully prepared by the intercalation method and combination of the intercalation-exfoliation method. The XRD analysis indicated that the basal spacing of kaolin expanded from 7.17 to 10.76 (KI) and 10 15.29 to 20.43 (KI) and 35.09 % (KIE), which implies successful intercalation of the urea in the interlayer of kaolin. The SEM analysis showed that kaolin has particle stacks that were slightly distantly spaced and few kaolin particles were transformed into smaller sizes after the modification process. ...
The intercalation method and combination of the intercalation-exfoliation method were applied to modify kaolin. The intercalation process was prepared using urea 60 % as an intercalated agent and the exfoliation process was carried out by ultrasonication. The samples were characterized by X-ray diffraction (XRD), X-Ray Fluorescence (XRF), scanning electron microscope (SEM), and particle size analysis (PSA). Experimental results showed that the physical properties of kaolin significantly improved after modification. This was indicated by the increasing interlayer spacing of modified kaolin, which was confirmed by SEM and XRD analysis. Based on XRF analysis, the loss on ignition value increased after kaolin modification, suggesting that the urea had successfully intercalated into the kaolin interlayer. Kaolin modification with intercalation method produced the most significant physical properties improvement, which increased surface area from 2508.607 to 27297.990 cm ² /g and decreased particle size average from 41.535 to 13.836 µm and had surface area close to illite clay.
... Ce matériau issu de la terre crue, souvent critiqué pour sa sensibilité à l'eau et son manque de durabilité, présente dans sa forme actuelle de nombreux avantages pour la construction de logements durables, confortables et économiques [5]. A cet effet, des recherches précédentes sur ces matériaux se sont intéressées au développement de composites à renfort, synthétique [6], organique [7] ou minéral [8]. Mais récemment, avec le développement du renfort naturel, une nouvelle voie dans le secteur de la recherche sur les polymères s'est avérée prometteuse [9]. ...
La latérite est la matière première la plus employée pour la confection des matériaux de construction en terre à travers différents procédés de stabilisation. Ces matériaux présentent de meilleures caractéristiques par incorporation avec des fibres végétales. L'objectif de cette étude est d'analyser le comportement mécanique et physique des BTC stabilisés à différentes teneurs de fibres de coco et de le comparer aux BTC stabilisés à 8 % de ciment. Pour se faire, un échantillon de sol prélevé dans la région de l'Ouest Cameroun a été analysé et corrigé avec du sable alluvionnaire, puis des échantillons de matériaux composites à différentes teneurs de fibres de coco (0 %, 0,2 %, 0,5 %, 0,8 % et 1 %) et ceux stabilisés à 8 % de ciment ont été élaborés. Ces différents échantillons ont été caractérisés à travers différents essais. Il en ressort que les blocs stabilisés à 0,5 % et à 0,8 % de fibres de coco présentent de meilleurs caractéristiques mécaniques, respectivement 6,88 MPa en compression et 1,17 MPa en traction par flexion en trois points mais sont très vénérable à de l'eau. Par contre, les blocs stabilisées à 8 % de ciment présentent des valeurs moyennes de 4,78 MPa en compression et 0,33 MPa en traction par flexion en trois points et sont moins sensible à de l'eau. Ainsi, les propriétés mécaniques des BTC s'améliorent avec l'incorporation avec les fibres de coco et sont optimales pour une teneur de 5 à 8 %, mais elles augmentent la porosité du matériau ce qui accroît sa sensibilité à l'eau contrairement au BTC stabilisée au ciment. Abstract Characterization of blocks produced by the addition of coconut fibers, laterite and cement-based construction materials Laterite is the most used raw material for the manufacture of earth building materials through different stabilization processes. These materials present better characteristics with the incorporation of vegetable fibers. The objective of this study is to analyze the mechanical and physical behavior of Compressed Earth Ludovic Ivan NTOM NKOTTO et al. Blocks (CEB) stabilized with different contents of coconut fiber and to compare it with CEB stabilized with 8 % of cement. To do so, a soil sample taken in the West Region of Cameroon was analyzed and corrected with alluvial sand, then samples of composite materials with different contents of coconut fiber (at 0 %, 0,2 %, 0,5 %, 0,8 % and 1 %) and those stabilized with 8 % of cement were elaborated. The various samples were characterized through different tests. The results show that the blocks stabilized with 0,5 % and 0,8 % of coconut fibers present better mechanical characteristics, respectively of 6,88 MPa in compression and 1,17 MPa in three-point bending tension but are very vulnerable to water. On the other hand, 8 % cement-stabilized blocks have average values of 4,78 MPa in compression and 0,33 MPa in three-point bending tension and are less sensitive to water. Thus, the mechanical properties of CEB improve with incorporation of coconut fibers and are optimal for a 5-8 % content, but they increase the porosity of the material which increases its sensitivity to water unlike cement-stabilized CEB.
... Mixing of two or more different polymers is now considered as an economical way to the development of new polymers [1]. Low-density polyethylene (LDPE) has good mechanical properties, withstand high temperatures, easy to handle so they have wide applications in the industry [2]. PP also has some characteristics such as high stiffness, low plasticity, but these characteristics making the PP structure are easily destroyed, so the PP applications are also limited [3]. ...
... MPa) due to the large concentration of fillers in a given region which affects the crystallization. However, if there is more filler content in the polymer matrix will lead to the formation of the micro-filler and uneven kaolin particle size, and induces the difficulty of achieving a filling of filler in the PP/LDPE composite matrix forming holes [2]. This result influences the stress concentration at the boundary of the particle/ matrix and leads to a decreasing in particle/ matrix interactions. ...
... The reason for this behaviour is believed to be the strong influence of the kaolinite on the chain dynamics. Fillers usually act as nucleation centers [17]. ...
Polypropylene (PP) is the most widely used semi-crystalline thermoplastic polymers due to its good thermal and mechanical properties, high dimensional stability and excellent process ability. In this research three types of different molecular weight PP named HP500 (HP), Atofina HG265FB (ATO) and Borealis PPH7089 (B) were used for production of nanocomposites at different kaolinite contents. Nanocomposites sample preparation starts by drying kaolinite and thorough mixing with PP and compounding at different formulations between 0 up to 30 wt% of kaolinite for two batches of processing; for spinning of fibers and filaments for 3D printing. Melt flow and crystallisation temperature of HP compounded formulations shows an increase with kaolinite content while Melt Flow Index for ATO PP decreased with increase of kaolinite content. Increase of crystallisation temperature implies kaolinite acts as a nucleating agent.
