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Increasing concern for the environment has led researchers to pay more attention to the fabrication of polymer biocomposites for many different applications. Polymer biocomposites have generally been fabricated utilizing synthetic or natural polymers with natural fillers. Recently, ionic liquids have been used for the pretreatment of natural fillers prior to the fabrication of polymer biocomposites. In this mini-review, four types of ionic liquids used for the pretreatment of natural filler are classified, specifically chloride-, diethyl phosphate-, acetate-, and bistriflimide-based ionic liquids. In addition, the pretreatment processes of natural fillers with ionic liquids are described in this review. Furthermore, the influence of ionic liquid pretreatment on the physicomechanical properties of polymer biocomposites is succinctly reviewed. Besides, the information presented in this review contributes to a clearer understanding of the process of ionic liquid pretreatment and the vital physicomechanical properties of polymer biocomposites. In summary, most ionic liquid pretreatments can improve almost all physicomechanical properties of polymer biocomposites.

An increase in the environmental consciousness at present has enhanced the awareness of researchers in utilizing biodegradable materials for the production of environmentally friendly products. Currently, biodegradable polymers, for example, polylactic acid, polybutylene succinate, polycaprolactone, etc., can be utilized as matrices to produce green composites. Meanwhile, natural fibers have been used as fillers for green composites as they are biodegradable and renewable. In this brief review, the physicochemical properties of selected biodegradable polymer, specifically polybutylene succinate, are demonstrated. Moreover, examples of natural fibers that are usually used to produce green composites are also shown. Additionally, practical methods employed for the preparation of green composites were exposed. The tensile properties of green composites, such as the tensile strength, tensile modulus, and elongation at break at different loadings of natural fibers, are also briefly reviewed. The information obtained in this review provides detailed differences in the preparation methods of green composites. In addition, this brief review supplies a clearer comprehension of the tensile properties of green composites for the usage of semistructural and packaging applications.

In this prelude study, the high-density polyethylene/kenaf core fiber (HDPE/KCF) biocomposites without and containing hydrophobic ionic liquid, namely 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([Emim][NTf2]), were prepared via melt mixing process. The process was carried out by using an internal mixer at 150°C with a rotor speed of 60 rpm. The prepared biocomposites were molded into sheets through compression molding technique at the same temperature. The molded biocomposites were cut into dumbbell and rectangular shapes for tensile and impact tests, respectively. The tensile and impact properties of the biocomposites were determined by using universal testing and impactor machines, correspondingly. The tensile test results indicated that the biocomposites containing [Emim][NTf2] had low tensile stress and tensile modulus. Nevertheless, the biocomposites possessed high tensile extension and impact strength compared to the biocomposite without [Emim][NTf2]. This study deduced that the presence of the hydrophobic ionic liquid like [Emim][NTf2] significantly influenced the tensile and impact properties of the HDPE/KCF biocomposites.

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, the biocomposite 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.

An improvement of ecological conscience currently has increased the consciousness of researchers in reducing the processing time and cost of solvent for the dissolution of cellulose. Latterly, ionic liquids have been employed to process cellulose as they are recyclable and nonvolatile. Besides that, biopolymers such as chitosan, chitin, starch, protein, and cellulose acetate can also be processed by using ionic liquids for diverse applications. In this short review, examples of imidazolium-based ionic liquids that are commonly used for the dissolution of cellulose are implied. Furthermore, examples of organic liquids that are utilized as co-solvents for ionic liquids were revealed. In addition, examples of imidazolium-based ionic liquid/co-solvent mixtures utilized in the dissolution of cellulose and other biopolymers are also demonstrated. The properties and applications of cellulose and its blends regenerated from different types of cellulose/imidazolium-based ionic liquid/co-solvent solutions are also shortly reviewed. The information acquired from this review gives a better understanding of the changes in the properties of regenerated cellulose and regenerated cellulose blends. In addition, this short review serves as a model basis for the creation of novel applications of regenerated cellulose and regenerated cellulose blends by utilizing imidazolium-based ionic liquid/co-solvent mixtures.

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.

Bamboo is an abundant natural resource in Asia and one of the high potential fibers used to reinforce polymer composites. This article presents a comparative study on the physicochemical and thermal properties of bamboo fiber (BF) from Gigantochloa scortechinii for untreated BF, steam explosion (SE) treatment BF, and steam explosion followed by alkali (SE-alkali) treatment BF. The physicochemical and thermal properties of BF were determined using energy dispersive X-ray (EDX) spectroscopy and thermogravimetric analysis (TGA), while scanning electron microscopy (SEM) was used to examine the surfaces morphologies. A Fourier transform infrared (FTIR) spectroscopy was utilized to detect the presence of functional groups. TGA results showed that SE BF was significantly more thermally stable than the untreated BF and SE-alkali treatment BF. Major changes in chemical composition and surface morphology of the bamboo fibers indicated that hemicellulose and lignin were removed by SE-alkali treatment. In conclusion, the BF surface is physically and chemically modified by the SE-alkali treatment.

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.

This study aims to investigate the effect of AgNPs on the mechanical, thermal and antimicrobial activity of kenaf/HDPE composites. AgNP material was prepared at different contents, from 0, 2, 4, 6, 8 to 10 wt%, by an internal mixer and hot compression at a temperature of 150 °C. Mechanical (tensile, modulus and elongation at break), thermal (TGA and DSC) and antimicrobial tests were performed to analyze behavior and inhibitory effects. The obtained results indicate that the effect of AgNP content displays improved tensile and modulus properties, as well as thermal and antimicrobial properties. The highest tensile stress is 5.07 MPa and was obtained at 10wt, TGA showed 10 wt% and had improved thermal stability and DSC showed improved stability with increased AgNP content. The findings of this study show the potential of incorporating AgNP concentrations as a secondary substitute to improve the performance in terms of mechanical, thermal and antimicrobial properties without treatment. The addition of AgNP content in polymer composite can be used as a secondary filler to improve the properties.

Polybutylene succinate (PBS)/rice starch (RS) blends were prepared via the hot-melt extrusion technique through the usage of a twin-screw extruder without and containing ionic liquid-based surfactants (ILbS). Two types of ILbS were used, specifically, 1-dodecyl-3-methylimidazolium trifluoromethanesulfonate, [C12mim][OTf] and 1-dodecyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [C12mim][NTf2] were mixed into the PBS/RS blends at the different contents (0–8 wt.%). The tensile and flexural results showed that the blends containing ILbS have a high tensile extension and tensile energy compared to the blend without ILbS. The blends containing ILbS also have a high flexural extension compared with the blend without ILbS. The blends containing [C12mim][NTf2] have a significant improvement in the tensile energy (up to 239%) and flexural extension (up to 17%) in comparison with the blends containing [C12mim][OTf]. The FTIR spectra demonstrated that the presence of ILbS in the blends generated the intermolecular interactions (ion-dipole force and hydrophobic-hydrophobic interaction) between PBS and RS. The DSC results exhibited that the melting points of the prepared blends are decreased with the addition of ILbS. However, the TGA results showed that the thermal decomposition of the blends containing ILbS are higher than the blend without ILbS. The values of decomposition temperature were 387.4 °C, 381.8 °C, and 378.6 °C of PBS/RS-[C12mim][NTf2], PBS/RS-[C12mim][OTf], and PBS/RS, respectively. In conclusion, the ILbS could significantly improve the physicochemical properties of the PBS/RS blends by acting as a compatibilizer.

This investigation aims to study the mechanical properties of the bamboo particle (BP) (Gigantochloa scortechinii) reinforced with semirigid Polyvinyl Chloride (PVC) composites before and after the steam explosion (SE)-alkali treatment. Mechanical properties, namely, tensile, flexural and impact strengths, were determined using universal tensile and impact testing machines according to ASTM standard. The tensile and flexural strengths of the composites were improved after SE-alkali treatment. Results indicated that the tensile and flexural strengths of the composites increased and reached the optimum values of 17.42 and 11.86 MPa, respectively for SE-alkali treatment BP reinforced semirigid PVC with 40 wt% particle content. The impact strength of SE-alkali-treated composites was unimproved due to less dense and rigid particle.

In this research, low-cost thermoplastic such as low-density polyethylene (LDPE) was used as a matrix for preparation of the biocomposites . On the other hand, kenaf core fibre (KCF) has been chosen as natural filler due to its availability and renewability. The hydrophobic (talc) and hydrophilic (calcium carbonate) minerals with different loading (0 to 15 wt%) were utilised as secondary fillers. The biocomposites were prepared via melt mixing technique. The processing, tensile and impact properties of the prepared biocomposites were recorded, measured and compared. From the processing recorder results, it was found that the stabilization torque of the LDPE/KCF biocomposites containing talc is lower than calcium carbonate. For the tensile test results, it can be observed that the tensile strength and tensile modulus of the biocomposites incorporated with talc are greater than calcium carbonate. On top of that, the biocomposites containing talc have low impact strength compared to calcium carbonate. It could be concluded that the LDPE/KCF biocomposites with the incorporation of hydrophobic mineral possessed stiff character, whereas the incorporation of hydrophilic mineral provided tough behaviour to the biocomposites.

Poly(vinylidene fluoride) (PVDF) is a versatile thermoplastic fluoropolymer with intriguing characteristics, which is receiving considerable attention from researchers in many areas. Recently, PVDF and its copolymer, such as poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) have been blended with ionic liquids to produce blend and composite materials for target applications. In this succinct review, two types of ionic liquids that are utilized for the preparation of PVDF and PVDF-HFP blends and composites, namely, hydrophilic and hydrophobic imidazolium-based ionic liquids, are reviewed. In addition, the effect of the ionic liquids on the physicochemical properties of the PVDF and PVDF-HFP blends and composites, is described as well. On top of that, a multitude of applications of the blends and composites are also succinctly reviewed. This review may give inspirations to the polymer blend and composite researchers in diversifying the applications of thermoplastic fluoropolymers through the utilization of ionic liquids.

A wide variety of quaternary ammonium compounds (QACs) have escalated the attraction of researchers to explore the application of QACs. The compounds have frequently been synthesized through alkylation or quaternization of tertiary amines with alkyl halides. Recently, QACs have been applied to compatibilize polymer blends and polymer composites in improving their thermo-mechanical properties. This concise review concentrates on the application of two types of QACs as compatibilizers for polymer blends and polymer composites. The types of QACs that were effectively applied in the blends and composites are quaternary ammonium surfactants (QASs) and quaternary ammonium ionic liquids (QAILs). They have been chosen for the discussion because of their unique chemical structure which can interact with the polymer blend and composite components. The influence of QASs and QAILs on the thermo-mechanical properties of the polymer blends and polymer composites is also described. This review could be helpful for the polymer blend and polymer composite researchers and induce more novel ideas in this research area.

Ionic liquids can typically be synthesized via protonation, alkylation, metathesis, or neutralization reactions. The many types of ionic liquids have increased their attractiveness to researchers for employment in various areas, including in polymer composites. Recently, ionic liquids have been employed to modify nanofillers for the fabrication of polymer nanocomposites with improved physicochemical properties. In this succinct review, four types of imidazolium-based ionic liquids that are employed as modifiers—specifically alkylimidazolium halide, alkylimidazolium hexafluorophosphate, alkylimidazolium tetrafluoroborate, and alkylimidazolium bistriflimide—are reviewed. Additionally, three types of ionic liquid-modified nanofiller/polymer nanocomposites—namely ionic liquid-nanofiller/thermoplastic nanocomposites, ionic liquid-nanofiller/elastomer nanocomposites, and ionic liquid-nanofiller/thermoset nanocomposites—are described as well. The effect of imidazolium-based ionic liquids on the thermo-mechanico-chemical properties of the polymer nanocomposites is also succinctly reviewed. This review can serve as an initial guide for polymer composite researchers in modifying nanofillers by means of ionic liquids for improving the performance of polymer nanocomposites.

An increase of environmental awareness recently has increased the interest of researchers in using of biopolymer-based films. The films have been prepared extensively by utilizing starch, carboxymethyl cellulose, chitosan, protein, gelatin, carrageenan, alginate, pectin, guar gum and pullulan. They are typically modified with surface-active agents (surfactants) such as glycerol monostearate, sucrose ester, sodium stearoyl lactate, sodium dodecyl sulfate, ethyl lauroyl arginate HCl, Span 20 to 80, Tween-20 to 80 and soy lecithin for improving the functional properties of the films. In this brief review, two types of biopolymer-based films that prepared through casting method were categorized, specifically solution- and emulsion-based films. The four types of surfactants, namely non-ionic, anionic, cationic and amphoteric surfactants that are regularly used to modify biopolymer-based films are also described. The functional properties of the films modified with different types of surfactants are briefly reviewed. This study enhances the attraction of researchers in biopolymer-based films and the improvement of new concepts in this niche area.

Three types of surfactants, specifically cationic, anionic, and nonionic, at different weight percentages were added into high-density polyethylene/low-density polyethylene/cellulose (HDPE/LDPE/cellulose) biocomposites via melt mixing. The cationic and anionic surfactants which are hexadecyltrimethylammonium bromide (HTAB) and sodium stearate (SS), respectively, were added from 4 to 20 wt%, whereas the nonionic surfactant which is sorbitan monostearate (SM) was added from 1 to 5 wt%. The mechanical testing results exhibited that the addition of HTAB increased tensile strength and tensile modulus, while SS deteriorated mechanical properties, while SM increased impact strength and tensile extension of the biocomposites. Based on the mechanical properties results, optimum weight percentages of HTAB and SM were 12 wt% and 4 wt%, respectively. The scanning electron microscopic micrographs displayed that the amount of cellulose fillers pullout decreased with the addition of HTAB, followed by SM, but it increased with SS. Fourier transform infrared spectra, X-ray diffractometer patterns, thermogravimetric analysis results, and differential scanning calorimetry thermograms have confirmed the presence of physical interactions only with the addition of HTAB and SM. Based on the results, compatibilizing effect was found in HTAB, whereas SM has not showed compatibilizing effect but instead plasticizing effect. However, neither compatibilizing nor plasticizing effect was exhibited by SS.

In this preliminary investigation, dolomite was added to the low-density polyethylene/kenaf core fiber (LDPE/KCF) biocomposites by using an internal mixer at 150°C, followed by compression molding at the same temperature. The dolomite contents were varied from 0 to 18 wt.%. The processing and stabilization torques, the stock and stabilization temperatures, the tensile and impact strengths, and the thermal decomposition properties of the prepared biocomposites have been characterized and analyzed. The processing recorder results of the LDPE/KCF biocomposites indicated that the stabilization torques and stabilization temperatures have increased with the addition of dolomite. Mechanical testing results showed that the presence of dolomite has increased the tensile stress, tensile modulus, and impact strength of the LDPE/KCF biocomposites. Thermogravimetric analysis results displayed that the thermal decomposition properties of the biocomposites have also increased with the increase of the dolomite content. This research led to the conclusion that the addition of dolomite in lower amounts (

Alkaline treatment of the black rice husk ash (BRHA) was done by immersing BRHA in 8 % sodium hydroxide, NaOH, solution for 24 hours and then the treated BRHA (TBRHA) was neutralized, washed and dried in an oven. The TBRHA was subsequently compounded with the polypropylene (PP) by using single screw extruder machine, and followed by compression molding at 185 °C. The physical properties results showed that the density and the water absorption behavior of the TBRHA filled PP biocomposite (TBRHA-PP) are higher and lower, respectively, when compared with the untreated BRHA filled PP biocomposites (UBRHA-PP). The melt flow index value of the TBRHA-PP biocomposite is also higher in comparison with the UBRHA-PP biocomposites. The mechanical properties results exhibited that the tensile stress, tensile strain, flexural modulus and impact strength of the TBRHA-PP biocomposite are higher than of the UBRHA-PP biocomposites. However, the tensile modulus of the TBRHA-PP biocomposite is slightly lower as compared with the UBRHA-PP biocomposites. Therefore, it could be concluded that the alkaline treatment of the BRHA has improved some of the physico-mechanical properties of the BRHA filled PP biocomposites.

In this research, eutectic-based ionic liquid specifically choline chloride/glycerol was prepared at a 1:2 mole ratio. The choline chloride/glycerol was added with the different content of surfactant (hexadecyltrimethylammonium bromide). The choline chloride/glycerol-hexadecyltrimethylammonium bromide was introduced into high-density polyethylene/agar biocomposites through melt mixing. The mechanical testing results indicated that the impact strength and tensile extension of the biocomposites increased with the introduction of the choline chloride/glycerol-hexadecyltrimethylammonium bromide. The scanning electron microscope, differential scanning calorimetry and thermal gravimetric analysis results exhibited that significant decrease in the number of agar fillers pull-out, melting point and thermal decomposition temperatures of the biocomposites are also due to the choline chloride/glycerol-hexadecyltrimethylammonium bromide. The Fourier transform infrared spectra and X-ray diffractometer patterns of the biocomposites introduced with the choline chloride/glycerol-hexadecyltrimethylammonium bromide demonstrate the presence of physical interactions, which contributes to the increase of compatibility between both high-density polyethylene and agar. In conclusion, high-density polyethylene/agar biocomposites could be compatibilized with eutectic-based ionic liquid containing surfactant, choline chloride/glycerol-hexadecyltrimethylammonium bromide., Comment: 14 pages, 9 figures, 4 tables, Journal of Reinforced Plastics and Composites

This study aims to examine the ability of magnetic Қ-carrageenan beads as an adsorbent in solid phase extraction towards chromium ions from aqueous solution. In this study, Қ-carrageenan magnetic gel-beads were obtained via interphase technique. The beads were kept in 0.3 M KCl to maintain gel strength. Physicochemical of the resulting materials were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and magnetometer. FTIR results have confirmed the presence of functional groups such as sulphate esters groups. The diameter of carrageenan beads was about ~764 μm where SEM micrographs showed the spherical formed shape of carrageenan beads and a rough surface with pores. The saturation magnetization value, M c , of carrageenan beads in this study was 18.78 EMU/g. The magnetic function of carrageenan beads is to facilitate bead collection and to get the Cr6+ ion that adsorbed onto the beads. The adsorption of chromium ions by magnetic carrageenan beads are through an ion exchange mechanism and formation of metal-ligand complex. Optimal timing for adsorption of chromium ions was at 60th minute. The optimal operation conditions can be achieved on pH value~1 and concentration of 100 ppm. Langmuir adsorption isotherm curve for Cr6+ is similar to Langmuir adsorption isotherm types III (unfavorable).

Nylon-6 is widely used as engineering plastic because it is easy to process, high tensile properties, resistant to chemical and abrasion. However, poor impact strength at low temperature makes it limitedly used in some applications. Nylon-6/liquid natural rubber (LNR) blends were prepared via emulsion dispersion with composition of 100nylon-6/0LNR, 95nylon-6/5LNR, 90nylon-6/10LNR, 85nylon-6/15LNR, 80nylon-6/20LNR and 75nylon-6/25LNR. Nylon-6 was dissolved in a 2,2,2-trifluoroethanol and chloroform mixture (1:1 TFE/CHCl3) and emulsified with hexadecyltrimethylammonium bromide (HTAB). LNR was dispersed into the nylon-6 emulsion to form homogeneous nylon-6/LNR emulsions and the emulsions were de-emulsified with methanol, filtered and dried. High impact behaviour was achieved at 85nylon-6/15LNR composition. DSC thermogram indicated a single glass transition temperature, T g and SEM images showed no phase separation between blend components implying homogeneous blends were obtained.

Agarose films were formed with the addition of 30 to 70 wt% choline chloride/urea eutectic-based ionic liquid (ChCl/Urea). The ChCl/Urea was prepared through complexation at a 1:2 mole ratio. The films were prepared by dissolving ChCl/Urea in distilled water followed by dispersion of the agarose at 95 °C. The solution was gelled at room temperature, and the formed gel was dried in an oven overnight at 70 °C. Mechanical testing indicated that the agarose film containing 60 wt% ChCl/Urea had higher tensile extension and tensile strain at break compared to the pristine agarose film. The addition of ChCl/Urea also reduced the glass transition temperature (Tg) of agarose films. Cross-section SEM images of the agarose films showed that surface roughness disappeared with the incorporation of ChCl/Urea. FTIR spectra confirmed the presence of intermolecular hydrogen bonding between agarose and ChCl/Urea. XRD patterns demonstrated that an amorphous phase was obtained when ChCl/Urea was added. Agarose films containing more ChCl/Urea exhibited higher transparency, as measured by a UV-Vis spectrometer. In summary, the physicochemical properties of agarose films were evidently affected by the incorporation of the ChCl/Urea as a plasticizing agent.

In this study, we are interested in the eutectic processing of chloride compounds, and decided to focus on ammonium based compounds that can provide sufficient insight in the fundamental chemistry. 14 types ammonium based chloride compounds namely ammonium chloride, methanaminium chloride, dimethylammonium chloride, trimethylammonium chloride, tetramethylammonium chloride, dodecyltrimethylammonium chloride, hexadecyltrimethylammonium chloride, carboxytrimethylmethanaminium chloride, phenyltrimethylammonium chloride, benzyltrimethylammonium chloride, (vinylbenzyl)trimethylammonium chloride, 2-acetoxytrimethylethanaminium chloride, (2-acetoxypropyl)trimethylammonium chloride and 2-(benzoyloxy)trimethylethanaminium chloride were used in this study. This research led to a hypothesis that the ammonium based chloride compounds could be react with the urea by complexing the hydrogen groups that are hydrogen bond donor giving eutectic mixtures. However, functional groups have plays an important role to influence thermal properties of those eutectic mixtures. This is regarded to be a motivating finding that will be important to most future research work involving complexation reaction for the production of eutectic mixtures.

In this study, lignin was isolated from rubber wood by means of ionic liquid (1,3-dimethylimidazolium methylsulfate). The optimum parameters to isolate lignin were investigated which include the concentrations of ionic liquid (0.1, 0.2, 0.3, 0.4, 0.5 moles), isolation durations (30, 60, 90, 120, 150 minutes), and isolation temperatures (25, 40, 60, 80, 100°C). The optimum parameters for lignin isolation are 0.5 moles concentration, 120 minutes and 100oC. Lignin could be isolated from rubber wood up to 13.03wt.% by ionic liquid however, in comparison with acid and alkaline isolation, they give better yields than ionic liquid which 22.15wt.% and 18.56wt.% of lignin, respectively. Lignin preliminary structures isolated by ionic liquid have been confirmed based on Fourier transform infrared (FTIR) results. From these results, isolated lignin by ionic liquid provides lignin without other related isolative. Apart from that, ionic liquid also could be recycled up to three times compared to acid and alkaline isolation methods.

This study aims to examine the ability of magnetic K-carrageenan beads as an adsorbent in solid phase extraction towards chromium ions from aqueous solution. In this study, K-carrageenan magnetic gel-beads were obtained via interphase technique. The beads were kept in 0.3 M KCl to maintain gel strength. Physicochemical of the resulting materials were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and magnetometer. FTIR results have confirmed the presence of functional groups such as sulphate esters groups. The diameter of carrageenan beads was about ~764 µm where SEM micrographs showed the spherical formed shape of carrageenan beads and a rough surface with pores. The saturation magnetization value, M, of carrageenan beads in this study was 18.78 EMU/g. The magnetic function of carrageenan beads is to facilitate bead collection and to get the Cr6+ ion that adsorbed onto the beads. The adsorption of chromium ions by magnetic carrageenan beads are through an ion exchange mechanism and formation of metal-ligand complex. Optimal timing for adsorption of chromium ions was at 60th minute. The optimal operation conditions can be achieved on pH value~1 and concentration of 100 ppm. Langmuir adsorption isotherm curve for Cr6+ is similar to Langmuir adsorption isotherm types III (unfavorable).