Preparation of Methyl Acrylate-Grafted Oil Palm Empty Fruit Bunch Fiber and its Application as a Filler in Poly(Vinyl Chloride)/Epoxidised Natural Rubber Composites

Graft copolymerization of methyl acrylate (MA) onto OPEFB fiber has been successfully carried out using hydrogen peroxide and ferrous ammonium sulfate as initiators in an aqueous medium. The effects of reaction temperature, reaction period and amount of monomer and initiators on the percentage of grafting were investigated. The results show that the percentage of grafting depends on reaction period and temperature as weil as concentration of monomers and initiators. The maximum percentage of grafting was obtained when the reaction was carried out using 33.36 mmol of MA, 6.00 mmol of H202a nd 0.191 mmol of ~ efo~r 21+0 minutes at 75OC. The presence of the functional group in the grafted polymers was characterized by FTIR spectroscopy. Scanning electron microscopy was used to study the surface morphology. Thermogravimetric analysis indicated that the grafted OPEFB is thermally stable than the virgin OPEFB. Effect of oil palm empty fruit bunch (OPEFB) fiber and poly(methy1 acrylate) grafted OPEFB Gn several mechanical properties of poly(viny1 ch1oride)lepoxidized natural rubber (PVCENR) 50150 and 70130 blends were also studied. The composites were prepared by mixing the fiber and the PVCJENR blend using HAKEE Rheomixer at the rotor speed of 50 rpm, mixing temperature 150°C and mixing period of 20 minutes. The fiber loadings were varied from 0 to 30% and the effect of fiber content in the composites on their tensile strength (Ts), Young's Modulus, Modulus at 100% (Mloo), elongation at break (Eb), flexural modulus, hardness and impact strength were determined. An increasing trend was observed in the tensile strength, Young's Modulus, flexural modulus, impact and hardness with the addition of grafted and ungrafted fiber to the PVCIENR blend. A higher elongation at break and tensile strength and decrease in the flexural and Young's modulus observed with the addition of PMA-g-OPEFB fiber compared to ungrafied fiber. This observation indicates that grafting of PMA onto OPEFB impart some flexibility to the blend. Scanning electron microscope confirms that the increase in properties is caused by improved fiber-matrix adhesion. There was less inclination for the fibers to pull out of the matrix. Furthermore the thermal analysis by Dynamic Mechanical Analysis (DMA) indicated shifting in the Tg of the PVCJENR composites with the addition of the OPEFB fiber. Thermogravemetric analysis (TGA) did not show any significant changes in the thermal stability. FTIR spectrums for the grafted and ungrafted fiber composites were almost identical. Effect of electron beam radiation on the tensile properties of the PVCJENR composites with 10% of fiber loading was studied. Electron beam irradiation and addition of crosslinking agent cause enhancement in tensile strength, Young's Modulus, Modulus at 100% (Mloo)a nd gel content, with a concurrent reduction in the elongation at break (Eb) of the PVCIENR composit

Preparation And Characterization Of Chitosan-Enr50 Biocomposites And Their Potential Application As Slow-Release Biodegradable Matrices For Cu(Ii) And 2-Naphthol In Aqueous Media

Over the years incorporation of chitosan in the matrices of elastomers has been of interest to researchers. However, solubility of chitosan in acidic aqueous media in contrast with epoxidized natural rubber which is not soluble has been a limitation. This has prompted us to investigate and hereby report our findings on the preparation, characterization, and the properties of three types of biocomposites containing chitosan (CTS) and epoxidized natural rubber (ENR) prepared via different methods. The first type, CTS-g-ENR, was obtained via acid-induced reaction of ENR50 with CTS in the presence of AlCl3.6H2O. Moreover, the NMR spectral analysis revealed that the epoxy content of CTS-g-ENR-P1 is 22.36%, suggesting that the grafting of CTS onto the backbone of the ENR had occurred. This revelation is affirmed by the presence of the characteristic absorption bands of CTS and ENR and the appearance of new bands at 1219, 902, and 733 cm-1 in the infrared spectrum of CTS-g-ENR-P1. The Tg of CTS-g-ENR-P2 is determined to be 2.88 °C which is significantly higher than that of ENR50 (-27.2 °C). The thermal stability of CTS-g-ENR is found to be higher compared to that of CTS, but lower than the one for ENR50. SEM micrographs of CTS-g-ENR-P1 show a smooth topographical texture with no phased-out entity, confirming that CTS has been successfully grafted onto the backbone of the ENR

Characterization of Oil Palm Empty Fruit Bunch (OPEFB) Fiber Reinforced PVC/ENR Blend

Previous studies on the blends of poly(vinyl chloride), PVC and epoxidized natural rubber, ENR revealed that the two polymers are miscible at all compositional ranges. In this work, the effect of oil palm empty fruit bunch(OPEFB) fiber and poly(methyl acrylate) grafted OPEFB on the thermal and structural properties of PVC/ENR blends were investigated. The composites were prepared by mixing the fiber and the PVC/ENR blend using HAAKE Rheomixer at the rotor speed of 50 rpm, mixing temperature 1508C and mixing period of 20 min.Studies on dynamic mechanical analysis (DMA) indicate that the Tg of the PVC/ENR composites shifts to higher temperature with the addition of the OPEFB fiber. Thermogravimetric analysis (TGA) does not show any significant changes in the thermal stability of the composites. However, Fourier Transform Infra Red (FTIR) spectrometry did not reveal the exact nature of interaction involved in the composites

Preparation and Characterization of Eco-Friendly Spent Coffee/ENR50 Biocomposite in Comparison to Carbon Black

This study investigates the impact of spent coffee biochar (Biochar) compared to carbon black (CB) as a partial replacement for carbon black in epoxidized natural rubber (ENR). Particle size and elemental analysis were used to characterize the biochar and CB. Cure characteristics, tensile, thermal, and morphological properties on the effect of biochar and CB as filler were studied. It was found that incorporating 10 phr of spent coffee biochar could improve the composites’ tensile properties and thermal performance compared to carbon black. However, the addition of biochar significantly affects the maximum torque compared to CB and delays the vulcanization time. SEM study shows that biochar has a strong effect on the morphology of composite films. The FTIR graph reveals no substantial difference between compounds with biochar and CB. According to the thermal calorimetric study, the thermal stability of ENR-Biochar is higher than that of ENR-CB. Additionally, these findings suggest that the utilization of spent coffee as a sustainable biochar could be further explored, but little has been done in epoxidized natural rubber (ENR)

Secondary Metabolites Profiling of Acinetobacter baumannii Associated with Chili (Capsicum annuum L.) Leaves and Concentration Dependent Antioxidant and Prooxidant Properties

Secondary bioactive compounds of endophytes are inevitable biomolecules of therapeutical importance. In the present study, secondary metabolites profiling of an endophytic bacterial strain, Acinetobacter baumannii, were explored using GC-MS study. Presence of antioxidant substances and antioxidant properties in chloroform (CHL), diethyl ether (DEE), and ethyl acetate (EA) crude extracts of the endophytic bacteria were studied. Total phenolic content (TPC), total flavonoid content (TFC), total antioxidant capacity (TAC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, and ferrous ion chelating assay were evaluated. A total of 74 compounds were identified from the GC-MS analysis of the EA extract representing mostly alkane compounds followed by phenols, carboxylic acids, aromatic heterocyclic compounds, ketones, aromatic esters, aromatic benzenes, and alkenes. Among the two phenolic compounds, namely, phenol, 2,4-bis(1,1-dimethylethyl)- and phenol, 3,5-bis(1,1-dimethylethyl)-, the former was found in abundance (11.56%) while the latter was found in smaller quantity (0.14%). Moreover, the endophytic bacteria was found to possess a number of metal ions including Fe(II) and Cu(II) as 1307.13 ± 2.35 ppb and 42.38 ± 0.352 ppb, respectively. The extracts exhibited concentration dependent antioxidant and prooxidant properties at high and low concentrations, respectively. The presence of phenolic compounds and metal ions was believed to play an important role in the antioxidant and prooxidant potentials of the extracts. Further studies are suggested for exploring the untapped resource of endophytic bacteria for the development of novel therapeutic agents

Silver Nanoparticles Synthesized by Using the Endophytic Bacterium <i>Pantoea ananatis</i> are Promising Antimicrobial Agents against Multidrug Resistant Bacteria

Antibiotic resistance is one of the most important global problems currently confronting the world. Different biomedical applications of silver nanoparticles (AgNPs) have indicated them to be promising antimicrobial agents. In the present study, extracellular extract of an endophytic bacterium, Pantoea ananatis, was used for synthesis of AgNPs. The synthesized AgNPs were characterized by UV&#8315;Vis spectroscopy, FTIR, transmission electron microscopy (TEM), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX), and Zeta potential. The antimicrobial potential of the AgNPs against pathogenic Staphylococcus aureus subsp. aureus (ATCC 11632), Bacillus cereus (ATCC 10876), Escherichia coli (ATCC 10536), Pseudomonas aeruginosa (ATCC 10145) and Candida albicans (ATCC 10231), and multidrug resistant (MDR) Streptococcus pneumoniae (ATCC 700677), Enterococcus faecium (ATCC 700221) Staphylococcus aureus (ATCC 33592) Escherichia coli (NCTC 13351) was investigated. The synthesized spherical-shaped AgNPs with a size range of 8.06 nm to 91.32 nm exhibited significant antimicrobial activity at 6 &#956;g/disc concentration against Bacillus cereus (ATCC 10876) and Candida albicans (ATCC 10231) which were found to be resistant to conventional antibiotics. The synthesized AgNPs showed promising antibacterial efficiency at 10 &#181;g/disc concentration against the MDR strains. The present study suggests that AgNPs synthesized by using the endophytic bacterium P. ananatis are promising antimicrobial agent

Viscoelastic Properties and Thermal Stability of Nanohydroxyapatite Reinforced Poly-Lactic Acid for Load Bearing Applications

We studied the reinforcing effects of treated and untreated nanohydroxyapatite (NHA) on poly-lactic acid (PLA). The NHA surface was treated with three different types of chemicals; 3-aminopropyl triethoxysilane (APTES), sodium n-dodecyl sulfate (SDS) and polyethylenimine (PEI). The nanocomposite samples were prepared using melt mixing techniques by blending 5 wt% untreated NHA and 5 wt% surface-treated NHA (mNHA). Based on the FESEM images, the interfacial adhesion between the mNHA filler and PLA matrix was improved upon surface treatment in the order of mNHA (APTES) &gt; mNHA (SDS) &gt; mNHA (PEI). As a result, the PLA-5wt%mNHA (APTES) nanocomposite showed increased viscoelastic properties such as storage modulus, damping parameter, and creep permanent deformation compared to pure PLA. Similarly, PLA-5wt%mNHA (APTES) thermal properties improved, attaining higher Tc and Tm than pure PLA, reflecting the enhanced nucleating effect of the mNHA (APTES) filler