Achmad Chafidz

Effect of Date Palm Fiber Loadings on the Mechanical Properties of High Density Polyethylene/Date Palm Fiber Composites

The trend of using natural fibers as green filler in the fabrication of polymer composites is increasing. One of these natural fibers is date palm fiber (DPF). Date palm fiber is considered as agricultural waste in certain areas, such as Middle East countries. Therefore, the utilization of this fiber in the composites fabrication is an interesting topic of research. In the current study, composites were prepared by melt blending DPF with high density polyethylene (HDPE). Five different DPF loadings were studied (i.e. 0, 5, 10, 20, 30 wt%). The effect of the DPF loadings on the mechanical properties and water absorption behavior of the composites were investigated. The tensile test result showed that tensile strengths of all the composites samples were all higher than the neat HDPE with the maximum improvement was achieved at the DPF loading of 5 wt% (i.e. DFC-5), which was about 19.23 MPa (138% higher than the neat HDPE). Whereas, the flexural test result showed that the flexural strength of the composites slightly increased compared to that of the neat HDPE only until 5 wt% DPF loading (i.e. DFC-5). Afterward, the flexural strength of the DFC-10 was equal to that of the neat HDPE, and decreasing with further increase of DPF loadings. Additionally, the water absorption test result showed that the water absorption rate and uptake of water (at equilibrium) increased with the increase of DPF loading.

High Density Polyethylene/Date Palm Fiber Composites: Effect of Fiber Loadings on the Dynamic Mechanical Thermal Properties

The increasing environmental issues has resulted in the trend of the use of renewable or natural source (green) fillers in the polymer composites fabrication. Among these green fillers is called natural fibers or plant fibers. One particular plant fibers that became the topic of the present work is date palm fiber (DPF). In the present work, DPF at different loadings (i.e. 0, 5, 10, 20, 30 wt%) were incorporated (as fillers) in the high density polyethylene (HDPE) matrix to fabricate HDPE/DPF composites. Further, we have investigated the effect of DPF loadings on the dynamic mechanical thermal properties of the composites. The dynamic mechanical thermal analysis (DMTA) results exhibited that the storage modulus of the composites increased with increasing DPF loadings. Additionally, all the storage modulus values of the composites were higher than the neat HDPE in all temperature ranges. For example, at temperature of 60°C, the storage modulus enhancement of the composites as compared to the neat HDPE were about 26, 76, 134, and 225% for 5, 10, 20, 30 wt% of DPF loadings, respectively. Additionally, the relationship between the DPF loadings (wt%) and temperature (°C) on the storage modulus of the HDPE/DPF composites was modeled using a logarithmic equation. Based on the data plotting between the experimental data and modeled data, the logarithmic equation was found to be fitted with the experimental data satisfactory.

Enhancing Mechanical Properties of Polyvinyl Alcohol Fiber Reinforced High Density Polyethylene Composites

In this work, high density polyethylene (HDPE)/polyvinyl alcohol (PVA) fiber composites have been fabricated via melt compounding by employing a twin-screw extruder. The resulted composites samples of four different PVA loadings (i.e. 0, 5, 10, 20 wt%) were then characterized via tensile test to investigate the effect of PVA loadings on their mechanical properties (i.e. modulus elasticity, tensile strength, toughness, and strain at break). Additionally, the surface morphologies of the composites (i.e. cryo-fractured and tensile fractured samples) were also studied by using a scanning electron microscopy (SEM). The SEM micrographs on the cryo-fractured sample showed that PVA fibers were perfectly embedded and well blended in HDPE matrix. Whereas, the SEM images of tensile-fractured samples showed that there was a fibrillation effect on the neat HDPE, while in the composites sample, there was an evident of broken fibers. Additionally, from the tensile test results, the modulus elasticity of the composites has increased by approximately 16, 39, and 81% (as compared to the neat HDPE) for PVAC-5, PVAC-10, and PVAC-20, respectively. Whereas, the toughness and strain at break of the composites have decreased.

Date Palm Fiber Reinforced High Density Polyethylene Composites: Effect of Fiber Loadings on the Melt Rheological Behavior

In the recent years, the trend of using renewable source (green) fillers in the composites fabrication is increasing. One of these green fillers is natural fibers, which referred to the plant fibers, such as date palm fiber (DPF). In the present work, high-density polyethylene (HDPE)/DPF composites have been prepared. Four different DPF loadings were used (i.e. 0, 5, 10, 20 wt%) to prepare the composites. The effect of DPF loadings on the melt rheological behavior of the HDPE/DPF composites were studied. The melt rheological test results showed that both of storage modulus (Gʹ) and loss modulus (Gʺ) increased with the increase of DPF loadings. Additionally, the Han plot showed an upward shift from neat HDPE (i.e. DFC-0) to DFC-20, which indicated that the melt rheological properties changed with the increase of DPF loadings. The complex viscosity |h*| of the composites samples also increased with the increase of DPF loadings. The increased was more significant at higher DPF loadings (i.e. DFC-20). Meanwhile, the Carreau-Yasuda model was found to be well fitted with the experimental data.

Poly(Vinyl Alcohol) Fiber Reinforced High Density Poly(Ethylene) Composites: Dynamic Mechanical Thermal Analysis

In the present work, high density polyethylene (HDPE)/poly (vinyl alcohol) (PVA) fiber composites with four different PVA fiber loadings (i.e. 0, 5, 10, 20 wt%) have been prepared via melt compounding method using a twin-screw extruder. The composites were characterized for their morphology by using a scanning electron microscopy (SEM). Whereas, the dynamic mechanical thermal analysis (DMTA) was carried out by using an oscillatory rheometer. The DMTA test was carried out under torsion mode using temperature sweep test on rectangular composites samples. The DMTA results showed that the storage modulus (G¢) of the composites were higher than that of the neat HDPE and increased with increasing PVA fiber loadings. This indicated that there was a considerable stiffness enhancement of the composites. For example, at temperature of 60°C, the increases of stiffness (i.e. storage modulus) of the composites were approximately 3, 31, and 54% for PVAC-5, 10, and 20, respectively. Whereas, at higher temperature (i.e. 120°C), the increases were about 4, 50, and 98% for PVAC-5, 10, and 20, respectively. These results indicated that even at higher temperatures, the enhancement of storage modulus of the composites was still high.

Poly(Vinyl Alcohol) Fiber Reinforced High Density Poly(Ethylene) Composites: Melting and Crystallization Behavior

In the present study, high density poly(ethylene) (HDPE)/poly(vinyl alcohol) (PVA) fiber composites were prepared via melt blending technique using a co-rotating twin screw extruder (TSE). The effect of four different PVA fiber concentrations (i.e. 0, 5, 10, 20 wt%) on the melt and crystallization behavior of the HDPE/PVA fiber composites were investigated. The surface morphology of the composites was analyzed by a scanning electron microscopy (SEM). Whereas, the melt and crystallization behavior of the composites were analyzed by a differential scanning calorimetry (DSC). The SEM analysis on the cryo-fractured surface of the HDPE/PVA fiber composites exhibited that the PVA fibers were well blended/distributed in the HDPE matrix. Additionally, the DSC test results showed that the addition of PVA fiber in the HDPE matrix did not significantly change the melting peak temperature (Tm) of the composites. Furthermore, a slight decrease of the crystallization peak temperature (Tc) can be observed when the PVA fiber was incorporated in the HDPE matrix, which indicated a weak nucleation ability of the PVA fibers in the HDPE crystallization process. The same trend was also observed for the crystallinity index (Xc). The crystallinity index of the composites decreased with increasing PVA fiber loadings.

Calcium Carbonate Reinforced Polypropylene Nanocomposites: Effect of Nano-Filler Loadings on the Melt Rheological Properties

In recent years, polymer-based nanocomposites have been investigated by many researchers due to their enhanced properties. Different types of nanomaterials have been used to produce polymer nanocomposites. One of them is nano-CaCO3. In the present work, nano-CaCO3 material reinforced polypropylene (PP) nanocomposites have been fabricated by melt compounding the PP pellets and nano-CaCO3 masterbatch. The effect of four different loadings of nano-CaCO3 (0, 5, 10, 15 wt%) on the melt rheological properties of the nanocomposites has been investigated. The morphology of the nanocomposites was analyzed by a Field Emission Scanning Electron Microscopy (FESEM) to study the dispersion state and distribution of nanoCaCO3 particles in PP matrix. Whereas, the melt rheological behavior of the nanocomposites was analyzed by an oscillatory rheometer. The FESEM micrographs showed that the nano-CaCO3 particles were well dispersed and distributed in the PP matrix. Additionally, the melt rheological analysis results showed that the complex viscosity of all nanocomposites samples were higher than that of neat PP and increased with increasing nano-CaCO3 loadings. Furthermore, the complex viscosity data from the rheological test has been fitted by Carreau-Yasuda equation and it was found to be well fitted.

Non-Isothermal Crystallization and Viscoelastic Behavior of Polypropylene/Nanoclay Composites Fabricated from Masterbatch by Using a Mini Extruder

Polypropylene(PP)/nanoclay composites samples have been fabricated by melt compounding the PP pellets with nanoclay masterbatch (i.e. 50 wt% of nanoclay) using a mini extruder. The effect of three loadings of nanoclay (i.e. 5, 10, and 15 wt%) on the morphology, non-isothermal crystallization, and viscoelastic behavior of the PP/nanoclay composites were investigated. All the nanocomposites samples were characterized by using Scanning Electron Microscope (SEM), Differential Scanning Calorimetry (DSC), and an oscillatory rheometer. The SEM results showed that the distribution of nanoclay in the PP was relatively good at all level of loadings. The DSC analysis results showed that the nanoclay has dramatically enhanced the crystallization temperature, from 117°C (for neat PP) to 127-129°C (for nanocomposites). Additionally, the frequency sweep test results exhibited that the presence of nanoclay increased the viscoelastic behavior of the PP matrix.