Effects of milling methods on tensile properties of polypropylene / oil palm mesocarp fibre biocomposite

The objective of this study was to evaluate the effects of milling methods on tensile properties of polypropylene (PP) / oil palm mesocarp fibre (OPMF) biocomposites. Two types of mills were used; Wiley mill (WM) and disc mill (DM). Ground OPMF from each milling process was examined for its particle size distribution and aspect ratio by sieve and microscopic analyses, respectively. Results showed that DM-OPMF had smaller diameter fibre with uniform particle size compared to the WM-OPMF. Surface morphology study by SEM showed that DM-OPMF had rougher surface compared to WM-OPMF. Furthermore, it was found that PP/DM-OPMF biocomposite had higher tensile strength compared to PP/WM-OPMF, with almost two-fold. Thus, it is suggested that small diameter and uniform size fibre may improve stress transfer and surface contact between the fibre and polymer matrix and cause welldispersion of filler throughout the polymer resulted in better tensile strength of PP/DM-OPMF compared to PP/WM-OPMF biocomposite. Overall, it can be concluded that disc milling could serve as a simple and effective grinding method for improving the tensile properties of biocomposite

Superheated steam treatment of oil palm mesocarp fiber improved the properties of fiber-polypropylene biocomposite

The effect of fiber surface modification by superheated steam (SHS) treatment and fiber content (30 to 50 wt.%) was evaluated relative to the mechanical, morphology, thermal, and water absorption properties of oil palm mesocarp fiber (OPMF)/polypropylene (PP) biocomposites. SHS treatment of OPMF was conducted between 190 and 230 C for 1 h, then the SHS-treated fiber was subjected to melt-blending with PP for biocomposite production. The biocomposite prepared from SHS-OPMF treated at 210 C with 30 wt.% fiber loading resulted in SHS-OPMF/PP biocomposites with a tensile strength of 20.5 MPa, 25% higher than untreated-OPMF/PP biocomposites. A significant reduction of water absorption by 31% and an improved thermal stability by 8% at T5%degradation were also recorded. Scanning electron microscopy images of fractured SHS-OPMF/PP biocomposites exhibited less fiber pull-out, indicating that SHS treatment improved interfacial adhesion between fiber and PP. The results demonstrated SHS treatment is an effective surface modification method for biocomposite production

Dammarane-Type Triterpenoids from The Stembark of Aglaia argentea (Meliaceae)

Two dammarane-type triterpenoids, 20S,24S-epoxy-3α,25-dihydroxydammarane (1) and 3α-acetyl-20S,24S-epoxy-3α,25-dihydroxydammarane (2), have been isolated from the stembark of Aglaia argentea. The chemical structure of compounds (1 and 2) were identified by spectroscopic evidences including UV, IR, 1D-NMR, 2D-NMR and MS as well as by comparing with previously reported spectral data. Those compounds were isolated from this plant for first time. Compounds (1 and 2) showed cytotoxic activity against P-388 murine leukemia cells with IC50 values of 23.96 and 8.14 mM, respectively.DOI:http://dx.doi.org/10.15408/jkv.v4i1.706

The effect of fiber milling on mechanical properties of polypropylene reinforced oil palm mesocarp fiber biocomposite

Oil palm mesocarp fiber (OPMF) is biomass residue abundantly available at palm oil mill. Being a lignocellulose, it can be used as reinforce material in biocomposite. In this study, the effect of OPMF milling on the mechanical properties of polypropylene (PP)/OPMF biocomposite was studied. Two types of mills were used, i.e. Wiley mill (WM) and disc mill (DM). Ground OPMF from each milling process was examined for its surface morphology, particle size distribution and aspect ratio by microscopic analyses. Ground OPMF was later sieved and fiber with particle size less than 150 μm was separated and mixed with PP using Thermo Haake mixer at 20 and 50 % (w/w) of fiber loading. Results showed that PP/DM-OPMF biocomposite had higher tensile strength compared to PP/WM-OPMF, with almost two-fold. From the SEM and light microscopic analysis, it can be observed that DM-OPMF had smaller diameter of fiber with almost uniform size of particles. Small diameter and uniform size of fiber may improve stress transfer between the fiber and polymer matrix, improve surface contact between polymer matrix and fiber and cause the well-dispersion of filler throughout the polymer. This explains the better tensile strength of PP/DM-OPMF compared to PP/WM-OPMF biocomposite. Overall, it can be concluded that disc milling could serve as a simple and effective grinding method which is able to improve the mechanical properties of biocomposite

Cytotoxic Triterpenoids from the Stembark of <i>Aglaia argentea</i> (Meliaceae)

Four dammarane-type triterpenoid compounds, dammar-24-en-3a-ol (1), 3-epi-cabraleahydroxy lactone (2), (E)-25-hydroperoxydammar-23-en-3b,20-diol (3), and dammar-24-en-3β,20-diol (4), were isolated from the methanolic extract of the stembark of Aglaia argentea. Compounds 1-4 were isolated for first time from this plant. The structure of isolated compounds were elucidated by spectroscopic methods including one and two-dimensional NMR as well as mass spectrometric analysis. Compounds, 1-4, along with a known synthetic analog, 20-hydroxy-dammar-24-en-3-on (5), were evaluated their cytotoxic activity against P-388 murine leukemia cells in vitro. The IC50 values of compounds, 1-5 were 9.09 ± 0.10, 68.53 ± 0.08, 5.89 ± 0.08, 22.40 ± 0.11, and 11.53 ± 0.08 µg/mL, respectively. Among the dammarane-type triterpenoids, compounds 1, 3, 4 and 5 having opened side chain showed the stronger activity, wheres compound 2 with cyclic side chain showed weak or no activity. In addition, compound 3 showed strongest activity, indicate that hydroperoxy group at side chain increase cytotoxic activity

Oil palm biomass powder and method for producing the same, and biomass composite molded article and method for producing the same

Provided are oil palm biomass powder preferable as a homogeneous industrial fiber material, and a composite shaped article with excellent mechanical properties, which comprises the oil palm biomass powder.The oil palm biomass powder has no peak in the temperature range of 180°C to 320°C but has a peak in the temperature range of 300°C to 400°C in a differential thermogravimetric curve, and 50% by mass or more of the oil palm biomass powder is in the major axis range of 1°C to 500°C. The biomass composite shaped article is produced by molding a composition comprising biomass powder and a thermoplastic resin or a thermo setting resin prepolymer at a mass ratio of 5:95 to 80:20