Eco-friendly Chemicals Research Articles

Smart, Sustainable, and Ecofriendly Chemical Design of Fully Bio‐Based Thermally Stable Thermosets Based on Benzoxazine Chemistry

AbstractInvited for this month′s cover are the groups at the Department of Macromolecular Science and Engineering, from Case Western Reserve University (CWRU), and Design and Chemistry of Macromolecules Group, from Institute of Technology in Polymers and Nanotechnology (ITPN), directed by Prof. Dr. Hatsuo Ishida and Prof. Dr. Pablo Froimowicz, respectively. The image symbolizes how in the ever‐growing ′Universe of Benzoxazines′ there is always room for new discoveries. The Full Paper itself is available at 10.1002/cssc.201600577.

Cover Picture: Smart, Sustainable, and Ecofriendly Chemical Design of Fully Bio‐Based Thermally Stable Thermosets Based on Benzoxazine Chemistry (ChemSusChem 15/2016)

Cover Picture: Smart, Sustainable, and Ecofriendly Chemical Design of Fully Bio‐Based Thermally Stable Thermosets Based on Benzoxazine Chemistry (ChemSusChem 15/2016)

Smart, Sustainable, and Ecofriendly Chemical Design of Fully Bio‐Based Thermally Stable Thermosets Based on Benzoxazine Chemistry

A smart synthetic chemical design incorporating furfurylamine, a natural renewable amine, into a partially bio-based coumarin-containing benzoxazine is presented. The versatility of the synthetic approach is shown to be flexible and robust enough to be successful under more ecofriendly reaction conditions by replacing toluene with ethanol as the reaction solvent and even under solventless conditions. The chemical structure of this coumarin-furfurylamine-containing benzoxazine is characterized by FTIR, (1) H NMR spectroscopy and two-dimensional (1) H-(1) H nuclear Overhauser effect spectroscopy (2D (1) H-(1) H NOESY). The thermal properties of the resin toward polymerization are characterized by differential scanning calorimetry (DSC) and the thermal stability of the resulting polymers by thermogravimetric analysis (TGA). The results reveal that the furanic moiety induces a co-operative activating effect, thus lowering the polymerization temperature and also contributes to a better thermal stability of the resulting polymers. These results, in addition to those of natural renewable benzoxazine resins reviewed herein, highlight the positive and beneficial implication of designing novel bio-based polybenzoxazine and possibly other thermosets with desirable and competitive properties.

OPTIMASI PROSES PEMBUATAN BIODIESEL DARI ASAM LEMAK SAWIT DISTILAT (ALSD) DAN DIMETHYL CARBONATE (DMC) MENGGUNAKAN KATALIS NOVOZYM®435

Biodiesel production has rapidly grown over the last decades, and it has attracted much attention in the market as fuel that promising substitute for petroleum diesel, because its physical and chemical properties and energy content are similar to those of petroleum diesel. The main problem in producing biodiesel is its high cost which could be reduced by use of less expensive feedstock. Therefore, in this work biodiesel is synthesized by enzymatic esterification from low quality feedstock which is unrefined and much cheaper than the refined oil, such as palm fatty acid distillate (PFAD) with dialkyl carbonate using immobilized lipase (Novozym®435). Enzymatic process has certain advantages over the chemical process, as it is less energy intensive, allowing the esterification of glycerides with high free fatty acid contents (PFAD, 85-95% FFA) and no enzymatic activity loss. Methanol replaced by dialkyl carbonate, especially DMC due to esterification (methanolysis) is close to equilibrium reaction whereas using DMC the intermediate compound immediately decomposes to carbon dioxide and an alcohol, which have been investigated. Moreover, DMC are cheap, eco-friendly chemical, non-toxic properties and widely available. Factors affecting the reaction such as DMC to PFAD molar ratio, reaction temperature, reaction time and catalyst concentration were systematically analyzed by response surface methodology (RSM) with central composite design (CCD). The optimal condition is using 6:1 molar ratio of DMC to PFAD at 60 oC, for a reaction time 3h in the presence 10wt% of catalyst (based on oil weight). The results showed that synthesis of biodiesel through enzymatic esterification using PFAD suitable for biodiesel production.

Cost-effective and eco-friendly management of Oligonychus coffeae, Calacarus carinatus and Acaphylla theae on tea with a pyridazinone molecule fenpyroximate 5% EC

The hazardous environmental effect, non-selectivity with non-target toxicity and longer residual persistence of conventional synthetic pesticides leads to resistance development and secondary pest outbreak opened the new modern era of bio-rational eco-friendly chemicals having novel mode of action with higher bio-efficacy on insects and mites control as an approach of integrated pest management. Field bio-effectiveness of a METI acaricide fenpyroximate 5% EC along with traditional acaricides as foliar spray against tea red spider mite, purple mite and pink mite was undertaken at Sukna Tea Estate and Kamalpur Tea Estate, West Bengal respectively with a 20+ years old plantation (TV-29) during 2013–2014 and 2014–2015. The treatments at higher dosages (30 and 60 g a.i. ha−1) were superior over standard checks propargite 57% EC and fenazaquin 10% EC. Mean percent reduction of red spider mite, purple mite and pink mite was minimum in treatments with higher dosages with mean value ranging from 73.83%-81.17%, 83.87%-91.66% and 83.90%-90.15% respectively. The test chemistry was relatively safe to important predatory fauna like Cheilomenes sexmaculata and Amblyseius ovalis. Highest yield was obtained in case of higher dosages (637.9 and 648.3 kg made tea ha−1), but fenpyroximate 5% EC at 30 g a.i. ha−1 (600 ml ha−1) proved most economic with the cost: benefit ratio of 1: 18.22, in the management of different mite pests infesting tea.

Sodium Bicarbonate Pretreatment on Rice Straw for Bioethanol Production and Utilizing the Waste Water of this Process to Absorb CO2 in Biogas.

The concept of small scale biorefinery from lignocellulosic biomass demonstrated the efficiency of energy and environment through research works at a pilot plant of University of Technology, VNU-HCM. The concept focused on studying bioethanol production in which pretreatment is one of key steps to achieve the efficiency. The pretreatment using NaOH solution 1.0 wt % removed lignin effectively but it is not considered as an eco-friendly chemical. Therefore, this study aims to investigate the alkaline pretreatment using Sodium Bicarbonate (NaHCO3), which is argued to be more environment-friendly and quite cheap. A variety of different conditions were investigated to optimize the pretreatment, including concentration of Sodium Bicarbonate (2.0-8.0 wt%), rice straw content (2.5-10.0 wt%), reaction temperatures (from room temperature to 80oC) and soaking time (4h-32h). The optimized condition was also investigated in combination with ultrasound and stirrer. The results showed that sodium bicarbonate is of quite potential to be used in the rice straw pretreatment. In addition, the waste of water from pretreatment was utilized to absorb CO2 in Biogas which was obtained from Thai My Demonstration plant in Cu Chi District.

Effect of gamma irradiation and its convergent treatment for control of postharvest Botrytis cinerea of cut roses

Postharvest diseases cause considerable losses to harvested crops. Among them, gray mold (Botrytis cinerea) is a major problem of exporting to cut rose flowers into Korea. Irradiation treatment is an alternative to phytosanitary purposes and a useful nonchemical approach to the control of postharvest diseases. Gamma irradiation was evaluated for its in vitro and in vivo antifungal activity against B. cinerea on cut rose varieties, ‘Shooting Star’ and ‘Babe’. The irradiating dose required to reduce the population by 90%, D10, was 0.99 kGy. Gamma irradiation showed complete inhibition of spore germination and mycelial growth of B. cinerea, especially 4.0 kGy in vitro. Antifungal activity of gamma irradiation on rose B. cinerea is a dose-dependent manner. A significant phytotoxicity such as bent neck in cut rose quality was shown from gamma irradiation at over 0.4 kGy (p<0.05) in both varieties. Although there is no significant difference in both varieties for fresh weight, in the case of flower rate, ‘Babe’ shows more sensitivity than ‘Shooting Star’. In vivo assays demonstrated that established doses in in vitro, over 4 kGy, could completely inactive fungal pathogens, but such high doses can cause severe flowers damage. Thus, to eliminate negative impact on their quality, gamma irradiation was evaluated at lower doses in combination with an eco-friendly chemical, sodium dichloroisocyanurate (NaDCC) to examine the inhibition of B. cinerea. Intriguingly, only the combined treatment with 0.2 kGy of gamma irradiation and 70 ppm of NaDCC exhibited significant synergistic antifungal activity against blue mold decay in both varieties. Together, these results suggest that a synergistic effect of the combined treatment with gamma irradiation and NaDCC can be efficiently used to control the postharvest diseases in cut rose flowers, and will provide a promising technology for horticulture products for exportation.

In vitro and in vivo effect of eco-friendly chemicals on alternaria blight disease (Alternaria brassicae) and yield attributes in Indian mustard (Brassica juncea)

The present investigation was done to evaluate the effect of different concentrations of five eco-friendly chemicals in vitro and in vivo, on the management of alternaria blight and yield attributes in Indian mustard (Brassica juncea cv. Varuna). Out of five eco-friendly chemicals, K2SO4 1000 ppm (64.28%) followed by ZnSO4 1000 ppm (63.88%) showed maximum inhibition of mycelial growth in comparison to check. 0.5% concentration of KCl (57.06%) followed by CaSO4 (59.50%) and K2SO4 (62.20%) showed significantly maximum effect on spore germination in comparison to check (74.60%). Spore intensity significantly increased by all the treatments except CaSO4 at 0.5% (40.18%) followed by K2SO4 at 0.5% (29.86%) and ZnSO4 0.75% (5.11% reduction) in comparison to check. The significantly minimum disease index on leaf over check was found by foliar spray of CaSO4 at 0.5%(23.58%) followed by CaSO4 at 1.5% (24.00%) and Na2B4O7.10H2O at 1.5% (24.08%). Na2B4O7.10H2O at 0.75% showed significantly lowest disease index (23.91%) on pod followed by K2SO4 at 1.5% (25.75%) and KCl at 1.5% (26.00%) in comparison to check. CaSO4 at 1.0% showed maximum number of primary branches (7.00), number of secondary branches (13.00) and total yield/ha (1917.30 kg/ha) in comparison to check. The results obtained from the present study suggested that K2SO4 showed maximum in vitro effect on Alternaria brassicae and CaSO4 and Na2B4O7.10H2O are providing maximum reduction of disease and increase in seed yield/ha that leads to efficient alternaria blight disease management strategies in field condition. These eco-friendly chemicals can protect the crops from alternaria blight diseases and increase the production and productivity of the Indian mustard crop.

セルロースナノファイバーを主体とした生物分解性・環境適合性石油開発用ケミカルの開発

セルロースナノファイバーを主体とした生物分解性・環境適合性石油開発用ケミカルの開発

Nitrification and denitrification characteristics in a sequencing batch reactor treating tannery wastewater

Long-term evaluation of a SBR fed with tannery wastewater (SBRtww) was carried out to study the periods of satisfactory and unsatisfactory performance in the nitrification and denitrification properties. Another SBR fed with synthetic nitrogen medium simulating tannery wastewater (SBRsww) was used to assess separately the end points of nitritation and nitratation by online monitoring of pH and DO. Flex point in the DO and pH profiles of the SBRsww cycle corresponding to the end point of nitritation was well observed, whereas the end point of nitratation was vaguely detected. The end point of nitritation suggested that the aeration phase can be reduced considerably and denitrification via nitrite can be facilitated to minimize oxygen requirements and reduce operational costs. During the long-term operation of SBRtww, stable and unstable phases of nitrification were observed. A maximum nitrification rate of 14.1 mg/L h was obtained during the stable phase of the reactor. Inhibiting substances in tannery wastewater was found to be the possible reason for the instability in nitrification. Denitrification property, however, was not much affected as that of nitrification. The maximum denitrification rate observed was 10.7 mg/L h. Nitrogen removal in an aerobic SBR through simultaneous nitrification-–denitrification could be a good option for tannery wastewater. SBR is a viable option for tannery wastewater compared to the conventional aerobic systems provided pollution control measures are conducted at the source level through the use of eco-friendly chemicals and cleaner processing methods to avoid nitrification inhibiting compounds in the effluent.

Copper recovery and gold enrichment from waste printed circuit boards by mediated electrochemical oxidation

The present study aims to develop an eco-friendly chemical–electrochemical process for the simultaneous recovery of copper and separation of a gold rich residue from waste printed circuit boards (WPCBs). The process was carried out by employing two different types of reactors coupled in series: a leaching reactor with a perforated rotating drum, for the dissolution of base metals and a divided electrochemical reactor for the regeneration of the leaching solution with the parallel electrowinning of copper. The process performances were evaluated on the basis of the dissolution efficiency, current efficiency and specific energy consumptions. Finally a process scale up was realized taking into consideration the optimal values of the operating parameters. The laboratory scale leaching plant allowed the recovery of a high purity copper deposit (99.04wt.%) at a current efficiency of 63.84% and specific energy consumption of 1.75kWh/kg cooper. The gold concentration in the remained solid residue was 25 times higher than the gold concentration in the initial WPCB samples.

Substantivity and Extraction of Eco - friendly Floral Dyes: Better Waste Management

This study attempts to provide an eco-friendly substitute for synthetic dyes from an unconventional but natural source. Colours obtained from nature have been part of our life for centuries. Today craftsmen in various parts of the world also use natural dyes in a limited way mainly because they are eco-friendly, non-toxic and have attractive shades. Though these dyes have been used for ages, there is limited scientific documentation on them. It is found that most flowers (especially corolla) contain colouring matters (e.g. anthocyanine and flavone) which may be in a free form or in combination with sugar (i.e. glycosidic). Most of the colouring matters present in flowers are soluble in hot water and is eco-friendly in nature. Thus, it can be applied to suitable substrates like textile fibres and paper. Natural dyes can be obtained from various plant parts, namely leaves, roots, bark, seeds, fruits and flowers. Synthetic dyes during manufacture and after use cause water pollution. Some synthetic dyes are very harmful and hazardous to health. Thus, in order to get an alternative source, substantivity of colouring matters obtained from flowers was tested on different natural fibres. Improvement of shades was achieved with fair to very good results using different eco-friendly chemicals. The results obtained show that natural dyes are almost as good as synthetic dyes.

Advances in QSPR/QSTR models of ionic liquids for the design of greener solvents of the future

In order to protect the life of all creatures living in the environment, the toxicity arising from various hazardous chemicals must be controlled. This imposes a serious responsibility on different chemical, pharmaceutical, and other biological industries to produce less harmful chemicals. Among various international initiatives on harmful aspects of chemicals, the 'Green Chemistry' ideology appears to be one of the most highlighted concepts that focus on the use of eco-friendly chemicals. Ionic liquids are a comparatively new addition to the huge garrison of chemical compounds released from the industry. Extensive research on ionic liquids in the past decade has shown them to be highly useful chemicals with a good degree of thermal and chemical stability, appreciable task specificity and minimal environmental release resulting in a notion of 'green chemical'. However, studies have also shown that ionic liquids are not intrinsically non-toxic agents and can pose severe degree of toxicity as well as the risk of bioaccumulation depending upon their structural components. Moreover, ionic liquids possess issues of waste generation during synthesis as well as separation problems. Predictive quantitative structure-activity relationship (QSAR) models constitute a rational opportunity to explore the structural attributes of ionic liquids towards various physicochemical and toxicological endpoints and thereby leading to the design of environmentally more benevolent analogues with higher process selectivity. Such studies on ionic liquids have been less extensive compared to other industrial chemicals. The present review attempts to summarize different QSAR studies performed on these chemicals and also highlights the safety, health and environmental issues along with the application specificity on the dogma of 'green chemistry'.

Repeated microwave-assisted exfoliation of expandable graphite for the preparation of large scale and high quality multi-layer graphene

The increasing demand for graphene's industrial application requires a new route for its mass production with high quality. Here, we report a facile, green, highly efficient and cost effective method for preparing a large amount of high quality graphene flakes, which is by the repeated microwave assisted exfoliation of expandable graphite (EG). The successful exfoliation of graphite is realized through the intercalation and decomposition of eco-friendly chemicals with the assistance of a microwave source. The chemical morphology and electrocatalytic performance analyses reveal that the graphene flakes are of high quality with little degradation.

A Search for Ecofriendly Detergent/Dispersant Additives for Vegetable‐Oil Based Lubricants

AbstractCarbonaceous deposits in automotive engines are the major problems associated with oil aging. Efficient detergents and dispersants have been used for several decades to solve this problem particularly in petroleum oils. But future lubricants and new engine hardware require development of new nontoxic detergent/dispersant additive technologies. Environmental concerns limit the formulation of the future lubricants. It requires not only the base oil to be ecofriendly but the additives also. In the present work, some of the potential ecofriendly chemical's molecules were identified. Specific detergents applications along with effects of chemical modifications were evaluated by Blotters Spot and Panel Coker Tests. Among the studied compounds, the PIB (polyisobutylene) succinimides are showing promising results at lower temperature, while at higher temperature piperazine derivatives citrate and oleate have the best potential to be develop as ecofriendly detergent/dispersant additives.

Synthesis of graphene nano-sheets using eco-friendly chemicals and microwave radiation

A novel approach to synthesize graphene nano-sheets by combining chemical treatment and microwave radiation is demonstrated using eco-friendly chemicals. Microwave radiation was used to produce strong expansion of the graphite worm in the thickness direction. The graphene nano-sheets obtained in this study were characterized by morphology images, nanoprofilometry, Raman and X-ray photoelectron spectroscopy. Besides being eco-friendly, the proposed method has also the attractive advantage of being rapidly able to produce a lot of graphene nano-sheets.

Effect of guar‐gum treatment on mechanical properties of vinylester resin matrix composites reinforced with jute yarns

AbstractThe focus of this work was to use an inexpensive and easily available water‐soluble natural resin like guar gum as a surface treating agent for jute yarns and to study their effect on the mechanical properties of the treated jute yarn reinforced vinylester resin matrix composites. Jute yarns were treated with 0.1, 0.2, and 0.3% guar gum solution at room temperature for 30 min. The composites were fabricated with the untreated and treated yarns and the vinylester resin having 36 wt % fiber loading. Maximum improvement was observed in the 0.2% guar‐gum treated, jute yarn reinforced composites. The flexural modulus and flexural strength improved by 23.85 and 7.7%, respectively, for the 0.2% treated composites. The fracture behavior of the composites differed considerably, depending on the concentration of guar gum that was used. The experimental results gave a positive indication that simple ecofriendly chemicals like guar gum can be used effectively as surface treating agents of jute yarns for enhancement of the mechanical properties of the jute composites and can be a success from the technocommercial point of view. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 557–563, 2005