Search

In this prelude study, the gellan gum/kenaf core fiber (KCF) biocomposite films were fabricated with the addition of imidazolium-based ionic liquids such as 1-butyl-3-methylimidazolium chloride (Bmim Cl), 1,3-dimethylimidazolium methylsulphate (Dmim MeSO4), 1-ethyl-3-methylimidazolium acetate (Emim Ac), and 1-ethyl-3-methylimidazolium trifluoromethanesulfonate (Emim OTf). The fabrication of the biocomposite films was carried out by mixing KCF and the ionic liquids in an aqueous solution, followed by dissolution of gellan gum in the same solution at a temperature of 90°C. The mixed solution was gelled at room temperature, and the formed gel was dried in an oven at 40°C for 48 hours to obtain a freestanding biocomposite film. The fabricated films were characterized by using a universal testing machine to acquire tensile properties. The tensile test results indicated that the biocomposite film added with Emim Ac possesses a higher tensile extension at maximum (up to 24%) than the biocomposite film without ionic liquid (added with glycerol). In addition, thebiocomposite film added with Emim OTf has a higher tensile modulus at maximum (up to 758%) compared to the biocomposite film without ionic liquid. In conclusion, the tensile properties of the gellan gum/KCF biocomposite films can be improved with the addition of Emim-based ionic liquids with different counter anions.

The tensile strength and flexural strength are the most important mechanical properties as they provide the value of maximum tensile stress and flexural stress. The objective of this study is to analyze statistically the tensile strength and flexural strength data obtained from a universal testing machine. The tests were conducted upon a thermoplastic, specifically high-density polyethylene (HDPE), which was in- house molded by using an injection-molding machine. Three different persons have performed the tensile and flexural tests. Three other laboratories have also been involved in these tests. The relative standard deviation (RSD) values were calculated to express the precision and repeatability of the tests. Later, the standard score (z-score) values were also calculated to aid the comparison of the data. Finally, the single- factor analysis of variance (ANOVA) was employed to investigate statistically significant differences between the means of the tensile strength and flexural strength data of each person and laboratory. From the calculation, the RSD values of all three persons and laboratories were lower than 5%, indicating that the data were consistent. The z-score values of all three persons were within the range from -2 to 2,suggesting that the data were close to average. However, the z-score value for one of three laboratories was not within the range, demonstrating that the data was unusual. The P-values of all three persons were higher than 0.05 (except for flexural strength), implying that the difference between the means of the data was not statistically significant. Nevertheless, the P-values of all three laboratories were lower than 0.05, indicating that the difference between the means of the data was statistically significant.

In this preliminary study, kenaf core fiber (KCF) was utilized as a natural filler for the preparation of the gellan gum/KCF biocomposite films. The films were prepared by casting gellan gum solutions containing glycerol and KCF, followed by gelation and drying. The weight ratio of gellan gum and glycerol was fixed at 2:3, while the content of KCF varied from 6 to 15 wt.% relative to the weight of gellan gum. The tensile properties of the prepared films have been determined by using a universal testing machine. The tensile test results demonstrated that the tensile extension and tensile energy at break of the biocomposite films have significantly increased with the incorporation of KCF. Nevertheless, the tensile stress and tensile modulus at maximum load have drastically decreased with the increase of KCF content. This study implied that the incorporation of KCF had enhanced the ductility of the gellan gum/KCF biocomposite films and at the same time, reduced the stiffness of the films.

In this primary research, 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ionic liquid ([C2mim][OTf]) was added to the high-density polyethylene/kenaf core fiber (HDPE/KCF) biocomposites by using an internal mixer at 150°C, followed by compression molding at the same temperature. The [C2mim][OTf] contents were varied from 0 to 10wt.%. The tensile properties of the prepared biocomposites have been determined by using a universal testing machine. The tensile results of the HDPE/KCF biocomposites indicated that the tensile strength and tensile modulus have decreased with the addition of [C2mim][OTf]. However, the presence of [C2mim][OTf] has significantly increased the tensile extension at break of the biocomposites. This research concluded that the addition of [C2mim][OTf] at the lower content (≈ 10wt.%) could act as a plasticizer for improving the flexibility of HDPE/KCF biocomposites.

In this initial investigation, oil palm empty fruit bunch (OPEFB) biocomposites incorporated with nickel zinc ferrite (NZFO) were prepared via heat blending technique followed by a compression molding technique, the percentages of NZFO were varied from 2.5 to 12.5%. All microwave measurements were carried out by means of Vector Network Analyzer (VNA) in the frequency ranges between 8 and 12 GHz. The attenuation measurement software was developed to retrieve data from VNA through a Visual Engineering Environment platform. The simulated and measured results showed that the biocomposites with a higher percentage of NZFO would have higher values of reflection coefficient and lower values of the transmission coefficient. On the contrary, the biocomposites with a lower percentage of NZFO have lower values of reflection coefficient and higher values of the transmission coefficient. In conclusion, the percentage of NZFO has significantly influenced the values of microwaves reflection and transmission coefficients of the OPEFB biocomposites.

In this research, natural fibre such as kenaf core fibre (KCF) was used as filler for preparation of the biocomposites. Low-density polyethylene (LDPE) has been selected as a polymer matrix for preparation of the biocomposites due to its low production cost. Besides that, chitosan was used as secondary filler to investigate its effect on mechanical properties of the prepared biocomposites. Brabender internal mixer was used to composite the materials at temperature of 150°C. The process was taken about 15 minutes to complete the compositing. After that, the biocomposites were moulded into sheet with 1 mm thickness by using compression moulding machine at 150 °C for 2 minutes. Then, the samples were cut into dumbbell and rectangular shapes to perform tensile and impact tests, respectively. For tensile test, the machine used was Instron universal testing machine which done according to the ASTM D638-10, while for impact test, the machine utilised was Instron impact testing machine which conducted in accordance with the ASTM D256-10. The results of tensile stress,tensile modulus, tensile strain and impact strength were recorded and analysed at the end of the tests.

In this study, a thermoplastic such as polycarbonate (PC) has been characterized to determine its tensile strength and flexural strength properties. The width and thickness of the PC samples have been measured, and then their average dimensions and standard deviation values were calculated. The samples have been characterized by using a universal testing machine. The tensile strength values of the dumbbell-shaped PC samples were determined according to ASTM D638-10, whereas ASTM D790-10 was applied to ascertain the flexural strength values of the rectangular-shaped PC samples. Based on the obtained results, the average tensile strength value is 58.978±0.258 MPa, whilst the average flexural strength value is 97.437±0.240 MPa. From the measurement uncertainty, the calculated expanded uncertainty for the tensile strength is 0.467 MPa at a confidence level of 95%. On the other hand, the calculated expanded uncertainty for the flexural strength is 0.806 MPa at a confidence level of 95% as well. In summary, the values of expanded uncertainty for the PC samples were particularly influenced by the standard uncertainty values of the tested samples and the expanded uncertainty values of the equipment used.

Biocomposite products are combination between synthetic or natural polymers as matrices and natural fibers as fillers. The products can fully or partially degradable by biological means. The manufacturing biocomposite products can be done by using several techniques such as compression moulding, injection moulding, solution casting, and so forth. This paper discusses briefly the advantages of compression moulding and its procedures. The machines and tools that have usually been used for this technique were also demonstrated. In addition, the types of materials that utilized for manufacturing biocomposite samples were described. The biocomposite products that have been or will be in the market were also indicated. It can be concluded that the compression moulding technique is the best technique for manufacturing biocomposite products since it could mould large products and it also produces less waste compared with other techniques.