The effects of NCO/OH ratio on propylene oxide‐modified oil palm empty fruit bunch‐based polyurethane composites

In this study, the effects of NCO/OH ratio on polyurethane composites prepared from propylene oxide‐modified oil palm empty fruit bunch (EFB‐PO) properties were studied. From the results obtained, the diffusion of solvents in the composites produced was classified as Fickian type. The molecular weight between crosslink points and degree of crosslinking were affected as the NCO/OH was increased. This phenomenon was attributed to the interaction between excess NCO and accessible OH groups from EFB‐PO to form a three‐dimensional network. From the mechanical testing results, it was found that the NCO/OH ratio had a significant effect on tensile and flexural test. However, no significant influence was observed on impact strength of the composites produced. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Thermal and mechanical properties of injection moulded heat-treated oil palm empty fruit bunch fibre-reinforced high-density polyethylene composites

ABSTRACT

Oil palm empty fruit bunch (OPEFB) was heat treated at 180°C using a vacuum oven for one hour, extruded and compounded with high-density polyethylene at 10%, 20% and 30% weight fraction. The composites then were injection moulded into dumb-bell shaped specimens. The effect of composition and heat treatment on the thermal properties of composites were investigated using Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC). The tensile and flexural properties were also tested using an Instron Universal Testing Machine. TGA shows an increase in the degradation peak temperature of the heat-treated composites. DSC revealed an increasing trend in the degree of crystallinity (X_c) of the matrix as the heat-treated empty fruit bunch was used as a filler. An increment in the tensile modulus and tensile strain were observed for the treated fibre composites. In addition, the tensile strength value was increased for treated fibre composites with lower fibre loading.     

The Effect of Glycol Type,Glycol Mixture,and Isocyanate/Glycol Ratio on Flexural Properties of Oil Palm Empty Fruit Bunch-Polyurethane Composites

Abstract

Oil palm empty fruit bunch (EFB)-polyurethane (PU) composites were produced. The effects of the isocyanate (NCO)/glycol (OH) ratio, glycol type, and mixtures (polyethylene glycol PEG 400 (M _w 400) and polypropylene glycol PPG 400 (M _w 400)) on the flexural properties were investigated. The NCO/OH ratio had a significant effect on the flexural properties of the EFB-PU composites. Composites made with PEG 200 exhibited higher flexural properties than with PEG 400 and PPG 400. The flexural properties were also found to be influenced by the PPG 400/PEG 400 ratio.     

Oil Palm Empty Fruit Bunch‐Polyurethane Composites: The Effect of Isocyanate/Glycol Ratio,Glycol Type,and Glycol Mixture on Impact Strength,Dimensional Stability,and Thermal Properties

Abstract

In this study, polyurethane (PU) composites have been produced with oil palm empty fruit bunch (EFB) and polyethylene glycol (PEG), molecular weight (MW) of 200 (PEG200), 400 (PEG400), and polypropylene glycol (PPG) with MW of 400 (PPG400) used as polyols. The effect of isocyanate (NCO)/hydroxyl (OH) ratio and PPG400/PEG400 ratio on the impact strength, dimensional stability (immersion test), and thermal behavior were investigated. The study revealed that as the NCO/OH ratio was increased, the impact strength increased, and the absorption and swelling of the composites either in water or dimethylformamide (DMF) decreased. The decrease in the onset and peak temperatures, and the increase in the enthalpy as the NCO/OH ratio was increased from 0.8 to 1.1 were attributed to the disruption of crystalline region due to the occurrence of cross‐linking. As for NCO/OH ratio of 1.1 onward, the increase in onset and peak temperatures were due to the increase in the degree of cross‐linking. On the other hand, the decrease in the enthalpy was due to the formation of allophanates. Thermal behavior of the composites made from the glycol mixture was predominantly influenced by the PPG400.     

Modification of oil palm empty fruit bunches with maleic anhydride: The effect on the tensile and dimensional stability properties of empty fruit bunch/polypropylene composites

Oil palm empty fruit bunch (EFB)‐filled polypropylene (PP) composites were produced. The EFB filler was chemically modified with maleic anhydride (MAH). The effects of the filler size and chemical modification of EFBs on the tensile and dimensional stability properties of EFB–PP composites were studied. The composites with MAH‐treated EFBs showed higher tensile strengths than those with untreated EFBs. This was attributed to the enhanced compatibility between the MAH‐treated EFBs and PP matrix, as shown in a scanning electron microscopy study. Fourier transform infrared analysis showed evidence of C?C and C?O bonds from MAH at 1630 and 1730 cm^?1, respectively. The MAH‐treated PP composites showed lower water absorption and thickness swelling than those with untreated EFBs. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 827–835, 2003     

Preparation and Characterization of Poly(lactic acid)-Based Composites Reinforced with Poly Dimethyl Siloxane/Ultrasound-Treated Oil Palm Empty Fruit Bunch

Oil palm empty fruit bunch fiber and polylactic acid were used to produce composites by melting cast method. Fiber loading was considered up to 40 wt%. Oil palm empty fruit bunch fibers were treated using ultrasound and polydimethylsiloxane to improve the interfacial adhesion. The structure and surface properties of the fibers were analyzed by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and contact angle measurement. Moreover, Fourier transform infrared spectroscopy, tensile, flexural, X-ray diffraction, contact angle, differential scanning calorimetry, and thermogravimetric analysis were used to investigate composites’ properties. The analysis revealed that polydimethylsiloxane treatment composites show reduced wettability with increased crystallinity.     

Characterization and Properties of Treated Oil Palm Empty Fruit Bunch Regenerated Cellulose Biocomposite Films with Butyl Methacrylate Using Ionic Liquid

Regenerated cellulose biocomposite films from oil palm empty fruit bunch and microcrystalline cellulose were prepared using N,N-dimethylacetamide and lithium chloride. The effects of oil palm empty fruit bunch contents and butyl methacrylate on properties of regenerated cellulose biocomposite films were investigated. At 2?wt% of untreated oil palm empty fruit bunch content showed highest crystallinity index, tensile strength, modulus of elasticity, and thermal stability but lower elongation at break than other oil palm empty fruit bunch content. The treated regenerated cellulose biocomposite films with butyl methacrylate showed better tensile strength, modulus of elasticity, thermal stability, and crystallinity index while Fourier transform infrared spectroscopy study showed interaction between cellulose and butyl methacrylate.     

The Physical Properties of Oil Palm Empty Fruit Bunch (EFB) Composites Made from Various Thermoplastics

Abstract

Oil palm empty fruit bunch (EFB)-based composites were produced using different types of thermoplastic as matrices. The composites were produced by using an internal mixer. The mechanical and water absorption properties of composites were investigated. Overall, the incorporation of EFB into the polymer matrix has resulted in the reduction of flexural strength. The poor performance has been attributed to the poor filler-matrix interaction. Both flexural and tensile modulus of PE and PP composites have been improved upon the addition of fillers, however, both PS and PVC composites showed a decreasing trend. Tensile strength and elongation at break results for all composites have been reduced as the result of incorporation of filler. This has been attributed to the poor filler-matrix interaction or compatibility, size irregularity and also decreased ductile deformation. Water absorption and thickness swelling increased as the filler loading is increased. This has been attributed to the presence of hyrophillic hydroxyl groups of the filler.     

Thermodynamic study of polymer–solvent systems by reversed-flow gas chromatography

Reversed-flow gas chromatography, a new method for studying heterogeneous catalysis, diffusion, adsorption, evaporation, and other related phenomena, is now applied to the determination of activity of the solvent in a polymer–solvent system in the whole range of polymer concentration, as well as for the calculation of excess partial molar thermodynamic functions of mixing. The systems used were polystyrene in cyclohexane, polyvinylacetate in cyclohexanone and polyvinylpyrrolidone in methanol. In the first system, which was studied in detail, weight fraction activity coefficients (a₁/w₁) at several temperatures (333.8–348.1 K) and various polymer concentrations (0.020–0.131 g/g) were determined. From the latter parameters weight fraction activity coefficients at infinite dilution (a₁/w₁)^∞ were computed. Flory–Huggins interaction parameters x and solubility parameters δ₂ were also determined. Finally, the thermodynamic parameters found by the present method are compared with those determined by other techniques or calculated theoretically.     

Enhancement of PVC/ENR blend properties by poly(methyl acrylate) grafted oil palm empty fruit bunch fiber

Effect of oil palm empty fruit bunch (OPEFB) fiber and poly(methyl acrylate) grafted OPEFB on several mechanical properties of poly(vinyl chloride)/epoxidized natural rubber (PVC/ENR) blends were studied. The composites were prepared by mixing the fiber and the PVC/ENR blends using HAKEE Rheomixer at the rotor speed of 50 rpm, mixing temperature 150°C, and mixing period of 20 min. The fiber loadings were varied from 0 to 30% and the effect of fiber content in the composites on their ultimate tensile strength (UTS), Young's modulus, elongation at break, flexural modulus, hardness, and impact strength were determined. An increasing trend was observed in the Young's modulus, flexural modulus, and hardness with the addition of grafted and ungrafted fiber to the PVC/ENR blends. However the impact strength, UTS, and elongation at break of the composites were found to decrease with the increase in fiber loading. An increase in elongation at break and UTS and decrease in the flexural and Young's modulus was observed with the addition of PMA‐g‐OPEFB fiber compared to ungrafted fiber. This observation indicates that grafting of PMA onto OPEFB impart some flexibility to the blend. The morphology of cryogenically fractured and tensile fracture surfaces of the composites, examined by a scanning electron microscope shows that the adhesion between the fiber and the matrix is improved upon grafting of the OPEFB fiber. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Swelling characteristics of NR/PU block copolymers and the effect of NCO/OH ratio on swelling behaviour

A series of (NR/PU) block copolymers (BCs) was prepared from toluene diisocyanate (TDI), 1,3-butane diol (1,3-BDO), and hydroxyl-terminated liquid natural rubber (HTNR), by solution polymerisation. The swelling characteristics of the BCs were investigated. Diffusion profile in various solvents and the sorption kinetics were studied. Arrhenius and thermodynamic parameters were evaluated from the diffusion data. Finally, the influence of NCO/OH ratio on the swelling behaviour was also studied. The equilibrium sorption value (Q_∞) decreased with increasing NCO/OH ratio for all the BCs. The samples have higher uptake of solvents with solubility parameter within a small range centred about 9 (cal/cm³)^1/2. Highly polar and non-polar solvents show minimum uptake. It was observed that polarity factor predominates in the solvent transport through the present block copolymer systems. The sorption behavior is also found to vary with the NCO/OH ratio employed in the preparation of polyurethane (PU) oligomers.     

Effects of moisture and other contaminants in friction composites

The role of water and other contaminants like salt water, iso-octane, and ethylene glycol on neat resin, composites, and friction materials have been investigated. The maximum solvent uptake and the diffusion coefficient of the solvent in these systems were determined and the experimental data was fitted to a Fickian model. The nature of the diffusion process was determined in each case and deviations from Fickian behavior were accounted for. For the neat resin and the composites, the diffusion coefficients of the liquids were of the order of 10^?10 cm²/s. After exposure to these contaminants, mechanical properties of all the systems were determined and a general degradation in properties was found. The flexural strength and fracture toughness showed reduction in values while the flexural modulus was not affected.     

Palm‐based bio‐composites hybridized with kaolinite

This study described the mechanical and thermal properties of hybrid bio‐composites from oil palm empty fruit bunch (EFB) fibers and kaolinite. The polyurethane (PU) used as matrix is formed by reacting palm kernel oil (PKO)‐based polyester with crude isocyanate. The blending ratio of PU to EFB fibers was fixed at 35 : 65 and kaolinite was added at 0, 5, 10, 15, and 20% (by weight). The occurrence of chemical interactions between the hydroxyl terminals in both fillers and the PU system was determined via FTIR spectroscopy. Hybrid bio‐composites showed improved stiffness, strength, and better water resistance with the addition of kaolinite to an extent. At 15% of kaolinite loading, maximum flexural and impact strengths were observed. The interaction between kaolinite with PU matrix and EFB fibers enhanced the mechanical properties of the bio‐composites, which was justified from the FTIR spectrum. However, over‐packing of kaolinite was observed at 20% kaolinite loading, which ruptured the cellular walls and degraded strength of the bio‐composites. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Adsorption kinetics of cadmium ions onto powdered corn cobs

Environmental pollution caused by the presence of toxic materials such as cadmium is becoming global problem and concern. This paper presents a report on kinetics of Cd²⁺ removal from aqueous solutions through adsorption using powdered corn cobs (PCC). Corn cobs were collected from a selected location, washed to remove sand, air dried, ground and sieved into different particle sizes. The selected properties of PCC were determined using acid digestion method. Adsorption capacities through kinetics of Cd²⁺ removal from synthetic solutions, typical raw water and domestic‐institutional wastewater were studied. Effects of pH, PCC particle size, initial concentration of Cd²⁺ and temperature on adsorption capacities were monitored through pseudo first‐ and second‐order models, Elovich and intraparticle diffusion models to present adsorption rate parameters. The study revealed that PCC contained 86.89% volatile solids, had 4.56% acid solubility, 0.52 water solubility and 2.33% ash content. PCC removed Cd²⁺ from aqueous solutions (synthetic, raw water, and wastewater). The relationship between time and concentration of Cd²⁺ remaining in the solution followed exponential functions with squared correlation coefficient ranging from 0.9928 to 0.9993, 0.8701 to 0.9284, and 0.8514 to 0.9290 for synthetic solution, raw water, and typical domestic‐institutional wastewater, respectively. Mechanism of cadmium adsorption onto PCC was in two separate stages linear portions in the first parts, while the final parts are curves indicating intraparticle diffusion. It was concluded that PCC is an effective adsorbent for Cd²⁺ removal. The estimated production cost was 0.068 USD as against 0.50, 2.12, and 3.12 USD for producing adsorbents from empty fruit bunches; pencom shell and sugar cane based activated carbons, respectively.     

Properties of nylon-6-based composite reinforced with coconut shell particles and empty fruit bunch fibres

Novel natural fibre composites of nylon-6 reinforced with coconut shell (CS) particles and empty fruit bunch (EFB) fibres have been investigated. Fillers were alkali treated before melt compounding with nylon-6. Mechanical, thermal and rheological properties of composites were measured. Tensile modulus was found to improve with both fillers up to 16% for nylon-6/CS composite and 10% for nylon-6/EFB composite, whereas a moderate increase in tensile strength was observed only with CS composites. Differences in the strengthening mechanisms were explained by the morphology of the two fillers, empty fruit bunch fibres having a weaker cellular internal structure. Observation of composite morphology using SEM showed that both fillers were highly compatible with nylon-6 due to its hydrophilic nature. Both fillers were found to cause a slight drop in crystallinity of the nylon matrix and to lower melt viscosity at typical injection moulding strain rates. Moisture absorption increased with addition of both fillers.     

Oil Palm Empty Fruit Bunch ‐ Polypropylene Composites ‐ The Effect of Modified Alcell Lignin as a Compatibilizer on Tensile Properties

Abstract

ALCELL lignin has been employed as compatibilizer in the empty fruit bunch (EFB)-polypropylene (PP) composites. The lignin has been chemically modified with toluene diisocyanate (TDI) to various weight loadings. The effect of lignin as compatibilizer on the tensile properties has been studied. The results show that the TDI-modified lignin is able to impart greater compatibility between EFB and PP. This is reflected in the greater tensile properties shown by the composites with TDI-modified lignin than the ones with the unmodified lignin.     

Polymer/carbon nanotube composites for liquid sensing: Selectivity against different solvents

An electrically conductive polymer composite (CPC) based on polycarbonate filled with 1.5 wt.% carbon nanotubes (CNTs) was investigated regarding its solvent selectivity when used as a sensor material for liquid detection. Based on the electrical response characteristics of the CPC when immersed in different solvents, “good” and “bad” solvents out of 59 test liquids were detected and the Hansen solubility parameters of the CPC were calculated using the “Hansen software” to be δ_D = 18.4 ± 0.2 MPa^0.5, δ_P = 10.9 ± 0.8 MPa^0.5, and δ_H = 4.1 ± 0.5 MPa^0.5.Based on the CPC's and solvents' Hansen solubility parameters the affinity between CPC and solvent represented by the distance in Hansen space was determined. As a second parameter the molar volume of the solvent molecules was used to describe the selectivity of the CPC by means of a quarter circle like area clearly separating “good” and “bad” solvents in a so-called solvent map.Whereas the Hansen solubility parameters are based on thermodynamics, the influence of the solvents' molar volume on the CPC's selectivity can be explained by diffusion processes. When increasing the molar volume of solvents having a similar chemical structure, a limiting value of the molar volume was found above which no solvent diffusion into the CPC was observed.Using this large number of solvents it could be clearly shown that the electrical response kinetics upon immersion into “good” solvents cannot be correlated with the Hansen solubility parameters of the CPC or their difference between CPC and solvent but is determined by the diffusion kinetics, which is governed by the solvents molecule size.     

Thermal and biodegradation properties of poly(lactic acid)/fertilizer/oil palm fibers blends biocomposites

Poly(lactic acid) (PLA) and NPK fertilizer with empty fruit bunch (EFB) fibers were blends to produced bioplastic fertlizer (BpF) composites for slow release fertilizer. Thermal properties of BpF composites were investigated by thermogavimteric analysis (TGA), differential scanning calorimetry (DSC), and morphological and degradation properties were anlayzed by scanning electron microscopy (SEM), soil burial test, respectively. TGA themogram display that neat PLA, PLA/NPK, and BpF composites degradate at different temperatures. DSC curves of PLA and other composites exhibited same glass transition temperature (T_g) value indicating that both major blend components are miscible. The T_g, crystallization temperature (T_c), melting temperature (T_m) values also decreased with increased amount of fertilizer and fibers. The T_m of BpF composites did not change with an increase in fertilizer content because thermal stability of PLA and PLA/NPK composites was not affected. Soil burial and fungal degradation test of PLA, PLA/NPK, and BpF composites were also carried out. Soil burial studies indicated that BpF composites display better biodegradation as compared with neat NPK. Fungal degradation study indicated that fungi exposure times of BpF composites show higher value of degradation as compared with PLA/NPK. We attribute that developed BpF composites will help oil palm plantation industry to use it as slow release fertilizer. POLYM. COMPOS. 36:576–583, 2015. © 2014 Society of Plastics Engineers     

Enzymatic Synthesis of Biodegradable Polyesters using Succinic Acid Monomer Derived from Cellulose of Oil Palm Empty Fruit Bunch

Oil palm empty fruit bunch fiber (OPEFB) is a lignocellulosic waste from palm oil mills. It is a potential source of glucose and xylose that can be used as raw materials for the production of valuable compounds such as succinic acid. The present study aims at producing biodegradable polyesters from OPEFB-derived monomer using enzymatic polymerization. Cellulose was extracted from OPEFB by using organosolv method. Enzymatic hydrolysis of cellulose was carried out using Celluclast and Novozyme 188 at 40?°C, with agitation rate of 145?rpm. Amount of enzyme and cellulose as well as reaction time were varied. The highest glucose concentration produced was 167.4?g/L. Succinic acid was produced when glucose was subjected to fermentation using Actinobacillus succinogenes with the highest concentration of 23.50?g/L. Biodegradable polyesters were produced when succinic acid together with 1,4-butanediol, glycerol and ethylene glycol, respectively, were subjected to Lipase (Candida Antartica CALB). Molecular weight obtained for poly(butylene succinate), poly(glycerol succinate), and poly(ethylene succinate) were 5.90?×?10⁴, 6.20?×?10⁴, and 4.53?×?10⁴ g/mol, respectively. The greatest extent of biodegradability of polyester found was 78.65?±?0.65%.     

Use of solvent free-volume parameters from 13c relaxation to study polymer/solvent diffusion behavior

Variable temperature ¹³C nuclear magnetic resonance (NMR) spinlattice (T₁) relaxation studies were carried out using pure ethylbenzene, tetrahydrofuran, and methanol samples. Single correlation times, determined from an isotropic rotational diffusion model, were correlated successfully using the free-volume equation. The solvent free-volume parameters estimated in this study were comparable with those determined from viscosity measurements. The solvent free-volume parameters estimated in this study were then used to correlate and predict diffusion behavior of polymer/solvent systems. The results were comparable with those using the parameters from viscometry when the Vrentas–Duda free-volume diffusion model was used.