Tetramethylthiuram Research Articles

Dendrimer stabilized nanoalloys for inkjet printing of surface-enhanced Raman scattering substrates

Research on paper substrates prepared by inkjet deposition of metal nanoparticles for sensing applications has become a hot topic in recent years; however, the design of such substrates based on the deposition of alloy nanoparticles remains less explored. Herein, we report for the first time the inkjet printing of dendrimer-stabilized colloidal metal nanoalloys for the preparation of paper substrates for surface-enhanced Raman scattering (SERS) spectroscopy. To this end, nanoassemblies containing variable molar ratios of Au:Ag were prepared in the presence of poly(amidoamine) dendrimer (PAMAM), resulting in plasmonic properties that depend on the chemical composition of the final materials. The dendrimer-stabilized Au:Ag:PAMAM colloids exhibit high colloidal stability, making them suitable for the preparation of inks for long-term use in inkjet printing of paper substrates. Moreover, the pre-treatment of paper with a polystyrene (PS) aqueous emulsion resulted in hydrophobic substrates with improved SERS sensitivity, as illustrated in the analytical detection of tetramethylthiuram disulfide (thiram pesticide) dissolved in aqueous solutions. We suggest that the interactions established between the two polymers (PAMAM and PS) in an interface region over the cellulosic fibres, resulted in more exposed metallic surfaces for the adsorption of the analyte molecules. The resulting hydrophobic substrates show long-term plasmonic stability with high SERS signal retention for at least ninety days.

Development of high melt strength polypropylene and its application in thermoplastic elastomeric composition

High melt strength polypropylene (HMS-PP) with a long-chain branched structure is a modified form of polypropylene (PP) which has basic properties of regular PP but with superior melt drawability. This paper reports on the development of gel-free HMS-PP from a linear isotactic PP through the introduction of long-chain branching on its backbone via a reactive extrusion process, using dicetyl-peroxydicarbonate (PODIC) alone or in combination with a coagent. The melt strength and the mechanical properties such as impact and flexural strength of PP showed improvements with the modification with PODIC. 5000 ppm by weight of PODIC was found to provide the best balance of properties. The efficacies of zinc diethyldithiocarbamate (ZDC) and tetramethyl thiuram disulphide (TMTD) as coagents in combination with PODIC to augment properties of HMS-PP further were explored. TMTD offered slightly enhanced performance benefits as compared to ZDC at an optimized concentration of 100 ppm by weight. The application potential of HMS-PP in thermoplastic elastomeric blends of HMS-PP with ethylene-propylene-diene monomer (EPDM) rubber at a fixed ratio of 35/65 by weight was also investigated. Structure-property correlations were established between the extent of long-chain branching in the modified PP and the properties of the resultant thermoplastic elastomeric composition.

Synergistic activities of binary accelerators in presence of magnesium oxide as a cure activator in the vulcanization of natural rubber

We describe the synergistic activities of binary vulcanizing accelerators in presence of magnesium oxide as cure activator in the vulcanization of natural rubber. Thiuram type tetramethyl thiuram disulfide (TMTD) and thiocarbamate type zinc dimethyl dithiocarbamate (ZDMC) accelerators in combination with dibenzothiazyl disulfide (MBTS) were investigated for the vulcanization of rubber. The cure, mechanical, and thermal properties of rubber vulcanizates were studied with magnesium oxide-based cure activator. Notable synergism in the delta torque, cross-link density, and mechanical properties was found when using binary accelerators with magnesium oxide. The zinc-containing thiocarbamate accelerator, ZDMC, showed better synergistic activity in presence of magnesium oxide than the non-zinc-based thiuram accelerator, TMTD. To find out the possibility of making a zinc-oxide-free natural rubber compound, a control compound was prepared with 5 phr of zinc oxide as a cure activator with the best evaluated binary accelerators system with magnesium oxide (3:6 millimolar ratio of ZDMC to MBTS). We also compared the curing and mechanical properties of carbon black-reinforced rubber with zinc oxide and magnesium oxide separately with this binary accelerators system. The results indicated that a completely zinc-oxide-free natural rubber compound was possible with comparable values in the mechanical properties, thermal properties and a higher rate of vulcanization.

Enhancing the Activity of Silver Nanowire Membranes by Electrochemical Cyclic Voltammetry as Highly Sensitive Flexible SERS Substrate for On-Site Analysis.

The development of high-quality flexible surface-enhanced Raman spectroscopy (SERS) substrates is crucial for developing rapid SERS analysis in situ. Silver nanowire membranes as novel flexible substrates could benefit from the high collection efficiency of analytes by wrapping complex surfaces or wiping the surfaces of samples. However, their low SERS performance impedes further applications of silver nanowire membranes in analyte detection. Herein, we report an ultra-high-sensitivity silver nanowire membrane synthesized by a simple and time-saving cyclic voltammetry (CV) method. After CV treatment, a part of the silver nanowires on the silver nanowire membrane turned into small nanoparticles and nanorods. This nanostructure’s reconstitution increased the analytical enhancement factor of silver nanowire membranes by 14.4 times. Scanning and transmission electron microscopy, UV-vis spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy were employed to investigate the transformation in the membrane nanostructure. The CV-treated substrates exhibited high surface-enhanced Raman activity and good temporal stability. The limits of detection (LODs) for p-aminothiophenol, crystal violet, tetramethylthiuram disulfide, sodium perchlorate, malachite green, fluoranthene, and potassium nitrate are 3.7 × 10−12 M, 5.1 × 10−11 M, 5.4 × 10−11 M, 6.3 × 10−9 M, 0.00693 ng, 0.0810 ng, and 0.0273 ng on this substrate, respectively. Additionally, the developed substrate is feasible for the detection of crystal violet in real samples. These results certify that CV-treated substrates possess broad application prospects in on-site SERS analysis.

English

Tetramethyl thiuram disulfide (thiram) is an important dithiocarbamate bactericide; it has been widely used for the control of various diseases in fruits, vegetables, seeds and food grains. However, it also causes environmental pollution problems and poses a threat to human health to a certain extent. Thiram induces tibial dyschondroplasia (TD) by causing oxidative stress and antioxidants imbalance in tibial growth plate in poultry. TD is a skeletal abnormality in fastgrowing poultry birds. It has been considered an economically important disease in poultry that affects poultry industry by carcass loss at meat processing plant due to decrease in disease resistance, production performance, and carcass quality and induces breast cysts and osteomyelitis worldwide. Oxidative stress is developed due to the imbalance of free radical oxygen, which disrupts the equilibrium state of oxidant and antioxidant tending to oxidation. This review is based on the current research, mainly to explore the relationship and mechanism between tibial dyschondroplasia and oxidative stress induced by thiram, which provides a new theoretical foundation for the further research of the related mechanism.

Effect of Wool Fiber on Structural and Mechanical Properties of Styrene-Butadiene Rubber Copolymer

In this work, a blend of styrene-butadiene rubber (SBR) filled with wool fiber (WF) was successfully prepared through compression molding using tetramethyl thiuram disulfide (TMTD) as a catalyst. The WF mixing to SBR with the proportion varying from 25 to 150 phr concerning the total weight of SBR. The effect of adding WF on the mechanical properties was examined. Also, the morphology and chemical structure properties were examined by used a scanning microscope (SEM) and Fourier infrared (FTIR), respectively. The results showed that the tensile strength and the elongation at the breaking stage are gradually reduced with the adding of WF. This may be due to WF are blended with the rubber randomly. The SEM images of WF/SBR blends showed some voids in the SBR matrix and weak adhesion between WF and SBR interface. The FTIR results revealed that the reaction of WF with the SBR matrix occurred to confirm the WF grafting SBR.

Potential Eco-friendly Application of Sugarcane Bagasse Ash in the Rubber Industry

Inorganic fillers (mainly obtained from residue recycling/reuse operations) have been widely used as an alternative reinforcement in polymer composites to replace commercial silica. In this study, we analyze the interaction between Sugarcane Bagasse Ash (SCBA) and natural rubber using Bis[3-(triethoxysilyl)propyl] Tetrasulfide (TESPT) as the silane coupling agent and Tetramethylthiuram Disulfide (TMTD) as the curing alternative system. Based on the results, we were able to validate their influence on the physical properties of the obtained composites. In particular, the coupling agent used in this study led to an improved interaction between SCBA and the polymer matrix, which was corroborated by the resulting mechanical response (stress–strain tests) and DMA (tensile strength) characterizations. Therefore, these findings encourage further research to explore a process at the industrial level to reuse SCBA waste and, thus, contribute to the protection of the environment.

Cross-Linked Density Determination of Natural Rubber Compounds by Different Analytical Techniques

This paper investigated the formation of crosslinks in natural rubber compounds in the vulcanization systems: conventional (CV), semi-efficient (SEV), and efficient (EV), processed with three types of accelerators: MBTS (dibenzothiazole disulfide), TMTD (tetramethylthiuram disulfide) and CBS (n-cyclohexyl 2-benzothiazole sulfenamide). The cross-linked densities were determined by organic solvent swelling, dynamic mechanical analysis (DMA), stress vs strain, and low-field nuclear magnetic resonance, the latter being the reference technique for comparison with the other results. It was found that the choice of accelerator type influences the processing time and the cross-linked density of the vulcanizate. The four techniques showed close values of cross-linked density for natural rubber compounds, demonstrating that the analytical techniques studied can be applied to determine cross-linked density.

Analysis of thiram derivatives use in plant complex of the Kursk region

The impact on the biosphere of anthropogenic factors is a serious environmental problem. Today, pesticides are becoming one of the important chemical factors that cause adverse environmental changes. Pesticides enter the human body through a contaminated hydrosphere, atmosphere, and food. Modern man is not able to grow and maintain crops without the use of pesticides. Penetrating into the human body, they cumulate, thereby contributing to the creation of threatening health situations. Despite this, modern human civilization cannot do without them. The purpose of the review was to study the circulation volume of derivatives of thiram, such as vitalon, vitavaks, vitasil, vitaros, tir and TMTD (Tetramethylthiuram Disulfide) in the agricultural complex of the Kursk region for the period 2007-2016. The data obtained at the Kursk Regional Plant Protection Station, as well as agrochemical protection station Kurskaya, were subjected to statistical analysis using the application Statistica 6.0. Circulating volumes of thiram's derivatives were examined in agro-industrial complex of Kursk area over a 10-year period. The proportion of fungicides of thiram's series with the release of agrochemicals dominant in the structure of seed crops cultivation technologies was investigated. A study of the structure of sown areas with the allocation of priority crops grown in the region was conducted, the total number of which amounted 80.76%. The ranking of the region by thirams derivatives was made. All studied fungicidal products of thiram are widely used for the cultivation of crops in the Kursk region. Identified regions with the biggest amount of making this group of agrochemicals in the soil are treated as high anthropogenic load zone and require the development of environmental protection. The volume of circulation of the studying group of pesticides can be dangerous to humans and animals, influence the formation of peoples somatic pathologies.

Stable Sodium Metal Anode Enabled by an Interface Protection Layer Rich in Organic Sulfide Salt.

Sodium (Na) metal is considered as a promising anode candidate for large-scale energy storage systems because of its high theoretical capacity and low electrochemical redox potential. However, Na anode suffers from a few challenges, such as the dendrite growth and severe parasitic reactions with electrolytes, which greatly hinder its practical applications. In this work, we demonstrate that an organosulfur compound additive (tetramethylthiuram disulfide) provides a facile and promising approach to overcome the above challenges in carbonate-based electrolytes. This unique organosulfur additive can in situ form a stable interfacial protection layer rich in organic sulfide salts on the sodium metal surface during cycling, leading to a stable stripping/plating cycling. Additionally, a cycling Coulombic efficiency of 94.25% is achieved, and the full battery using Prussian Blue as a cathode delivers a reversible capacity of 86.2 mAh g-1 with a capacity retention of 80% after 600 cycles at 4 C.

Influence of iron ore concentrate (magnetite) on the kinetics of butadiene–styrene rubber-based blend curing in the presence of different accelerators

Objectives. To investigate the possibility of using a cheaper ingredient, such as magnetite, in the synthesis of rubber compounds based on butadiene–styrene rubber by examining its effect on the process of sulfuric vulcanization of butadiene–styrene rubber in the presence of various accelerators.Methods. The influence of magnetite on the vulcanization kinetics was studied using an Alpha Technologies PRPA 2000 rotorless rheometer. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) were performed using a Mettler Toledo TGA/DSC 2 device to evaluate the effect of magnetite on the butadiene–styrene rubber-based vulcanizates’ oxidation.Results. Magnetite was found to affect the kinetics of SBR-1500 butadiene–styrene rubber sulfuric vulcanization in the presence of thiazole-type accelerators (2-MBT, 2-MBS); in contrast, magnetite was inactive in the case of diphenylguanidine, sulfenamide T, and tetramethylthiuram disulfide. The obtained TGA/DSC data showed that magnetite has no significant effect on the butadiene–styrene rubber-based vulcanizates’ oxidation and thermal destruction.Conclusions. The obtained data confirmed magnetite’s capability to act as a butadiene–styrene rubber sulfuric vulcanization activator in the presence of various accelerators. The most significant effect was observed in the presence of thiazole-type accelerators.

Three‐Component Synthesis of 2‐Substituted Thiobenzoazoles Using Tetramethyl Thiuram Monosulfide (TMTM) as Thiocarbonyl Surrogate

A metal‐free synthesis of 2‐benzyl/allyl‐substituted thiobenzoazoles was developed starting from tetramethyl thiuram monosulfide (TMTM) which served as thiocarbonyl surrogate. By using 2‐aminophenols (or 2‐aminothiophenols, or 1,2‐phenylenediamines) and TMTM as starting materials, 2‐mercaptobenzoazoles could be synthesized efficiently. The subsequent C–S bond formation with benzyl/allyl halides gave the final products (2‐benzyl/allyl‐substituted thiobenzoazoles) with good to excellent yields. The metal‐free conditions, inexpensive and easily available starting materials, and broad substrate scope are the advantageous features of this protocol.

The Fungicide Tetramethylthiuram Disulfide Negatively Affects Plant Cell Walls, Infection Thread Walls, and Symbiosomes in Pea (Pisum sativum L.) Symbiotic Nodules.

In Russia, tetramethylthiuram disulfide (TMTD) is a fungicide widely used in the cultivation of legumes, including the pea (Pisum sativum). Application of TMTD can negatively affect nodulation; nevertheless, its effect on the histological and ultrastructural organization of nodules has not previously been investigated. In this study, the effect of TMTD at three concentrations (0.4, 4, and 8 g/kg) on nodule development in three pea genotypes (laboratory lines Sprint-2 and SGE, and cultivar ‘Finale’) was examined. In SGE, TMTD at 0.4 g/kg reduced the nodule number and shoot and root fresh weights. Treatment with TMTD at 8 g/kg changed the nodule color from pink to green, indicative of nodule senescence. Light and transmission electron microscopy analyses revealed negative effects of TMTD on nodule structure in each genotype. ‘Finale’ was the most sensitive cultivar to TMTD and Sprint-2 was the most tolerant. The negative effects of TMTD on nodules included the appearance of a senescence zone, starch accumulation, swelling of cell walls accompanied by a loss of electron density, thickening of the infection thread walls, symbiosome fusion, and bacteroid degradation. These results demonstrate how TMTD adversely affects nodules in the pea and will be useful for developing strategies to optimize fungicide use on legume crops.

Thermal and mechanical behavior of SBR/devulcanized waste tire rubber blends using mechano–chemical and microwave methods

Abstract The engagement of waste tires rubber as source of raw materials for different applications can be a partial solution to the great environmental problems caused by these products. In this study, waste tire rubber was devulcanized using both mechano–chemical and microwave methods. This process was achieved using different concentrations of 2-mercapto benzothiazole disulfide (MBTS) and tetramethylthiuram disulfide (TMTD) as a devulcanizing agent and different microwave devulcanizing times. The optimum content of both MBTS, TMTD and suitable microwave treatment time to make continuous film were noted. The devulcanized waste rubber was then added, at different concentrations, to virgin styrene–butadiene rubber (SBR). The thermal properties and dynamic mechanical behaviors were investigated for all blends. The thermal analysis proved that natural and styrene butadiene rubber are the main two constituents of the waste tire rubber utilized in this study. The mechanical behavior of the SBR blends remarkably improved by using 20 phr waste rubber (WR) devulcanized by 2 phr MBTS and by exposure for 2.2 min to microwaves. Storage modulus, tearing strength and tension set behaviors notably improved for all SBR/WR blends by irradiating with gamma ionizing radiation with a dose of 100 kGy and further improvement could be attained by increasing the dose up to 200 kGy.

Highly sensitively detecting tetramethylthiuram disulfide based on synergistic contribution of metal and semiconductor in stable Ag/TiO2 core-shell SERS substrates

In this study, we successfully constructed Ag/TiO2 core-shell nanoparticles through an easy wet chemistry method for SERS study. Compared to Ag cores, the Ag/TiO2 core-shell nanoparticles presented higher SERS sensitivity, owing to a synergistic SERS enhancement arising from electromagnetic field effect of Ag cores and chemical enhancement of TiO2 shells. Furthermore, uniform TiO2 shells were able to effectively protect the internal Ag cores against destruction in external environment and thus storage stability of Ag/TiO2 nanoparticles was prominently improved. The as prepared Ag/TiO2 core-shell nanoparticles were applied to quantitatively sense tetramethylthiuram disulfide (TMTD) in solution using a portable Raman spectrometer. The results showed that the SERS intensity of 563 cm−1 assigned to S-S stretching mode had a good linear relationship with the concentration of TMTD with the correlation coefficient (R2) of as high as 0.99 and the detection limit of as low as 1.15 × 10−10 M. Consequently, the prepared Ag/TiO2 nanoparticles present specially advantage of quantifying S-S groups by SERS, because the TiO2 shell could act as a spacer between Ag cores and TMTD molecules and keep the S-S bonds intact.

Large-Scale Flexible Surface-Enhanced Raman Scattering (SERS) Sensors with High Stability and Signal Homogeneity

Flexible surface-enhanced Raman scattering (SERS) sensors have attracted great attention as a portable and low-cost technique for chemical and bio-detecting. However, flexible SERS sensors tend to suffer low signal spatial homogeneity due to their uneven active plasmonic nanostructures (hot-spots) distribution, and quick degradation of SERS sensors' sensitivity due to low adhesion of hot-spots and flexible substrates during fast sampling. Herein, a large area (20×20 cm2) polyimide (PI) based SERS sensor is exploited for trace detection with high signal homogeneity and stability. The SERS sensor is constructed from PI through in situ growth of silver and gold core-shell nanoparticles (Ag@Au NPs) based on chemical reduction and galvanic replacement process. Benefiting from the abundant carboxyl groups on the surface cleavaged PI, densely and uniformly distributed Ag@Au NPs are successfully prepared on the film under ambient conditions. The high Raman enhancement factor (up to 1.07 × 107) and down detection capability of nanomolar (10-9 M) detection limits are obtained for this flexible SERS sensor. The uniform Raman signals in the random region show well signal homogeneity with a low variation of 8.7%. Moreover, the flexible SERS sensor exhibited superior efficiency durability after storage 30 days even after mechanical stimuli (bending or torsion) 500 cycles. The pesticide thiram (TMTD) residue has been rapidly traced by direct sampling from the apple surface, and a sensitivity of 10 ng/cm2 for TMTD was achieved. These findings show that the PI-based SERS sensor is a very strong candidate for broad and simple utilization of flexible SERS for both laboratory and commercial applications in chemical and biomolecule detections.

Agroecological techniques for protecting soybean crops from phytopathogens

The aim of this research was to study the influence of biofungicides and growth regulators on protecting soybean crops from fungal diseases, allowing the production of environmentally friendly and high-quality products. The main pathogens of soy diseases in the Khabarovsk territory are root rot and leaf-stem infections. The means of protection applied in this study reduced the intensity of development of these diseases. The greatest biological effectiveness against root rot was found when the drugs Zircon, Bisolbifit and Tetramethylthiuram Disulfide (TMTD) with Optimo were used. The use of Zircon, Extrasol and Nutri-Phite with water softener Spartan reduced the infection of soy plants with leaf-stem diseases. With these protection systems, the yield level ranged from 3.62 to 3.88 t/ha.

Evaluation of bio-formulations of fungal and bacterial biological control agents in combination with fungicide in different mode of application for integrated management of tomato wilt

Wilt (Fusarium oxysporum f. sp. lycopersici) of tomato is one of the major factors for low productivity of the crop. Bio-control agents along with fungicides were evaluated in various modes of applications to develop an efficient wilt management module. Tomato seedling roots dipped in fungicide carbendazim and bioformulation of Trichoderma harzianum and T. viride separately provided the lowest wilt incidence with the highest shoot and root lengths, plant dry weight, number and weight of fruits with statistically similar performance. Both T. harzianum and T. viride based soil application formulations showed similar performances. Further based on these results, seedling root dip and soil application of T. harzianum and T. viride separately and in combinations along with fungicides and Bacillus subtilis were evaluated. Combined application of PBP10G (T. harzianum) in soil and seedling root dip in a suspension of Pusa 5SD (T. harzianum) + fungicide carboxin 37.5% + tetramethyl thiuram disulfide 37.5% (Vitavax power) provided the highest shoot length, fruit number and weight along with the lowest wilt incidence. The wilt incidence observed in the treatment was alike to that of T. harzianum (PBP10G) × T. viride (Pusa 5SD) + Vitavax power and T. viride (PBP10G) × T. harzianum (Pusa 5SD) + Vitavax power. Thus, the application of Trichoderma based formulations with fungicide Vitavax power not only reduced the incidence of wilt, but also enhanced the growth of plants and fruit yield. The module developed is entirely new and proved effective for tomato wilt management.

Three-Component Synthesis of 2-Alkylthiobenzoazoles in Aqueous Media

A highly efficient three-component protocol for the synthesis of the 2-alkylthiobenzoazoles is described. Tetramethylthiuram disulfide (TMTD) cyclized with o-aminothiophenols, generating the intermediate 2-mercaptobenzothiazoles, and the successive C–S coupling with halogenated alkanes afforded a series of 2-alkyl-substituted thiobenzothiazoles smoothly in a one-pot process. This procedure could also be utilized for the preparation of 2-alkyl-substituted thiobenzoxazoles and 2-alkyl-substituted thiobenzimidazoles. Inexpensive and easily available starting materials, metal catalyst-free, broad substrate scope, and water as solvent are the features of this protocol.

In Situ Recyclable Surface-Enhanced Raman Scattering-Based Detection of Multicomponent Pesticide Residues on Fruits and Vegetables by the Flower-like MoS2@Ag Hybrid Substrate.

Pesticides, extensively used in agriculture production, have received enormous attention because of their potential threats to the environment and human health. Hence, in this study, a kind of highly sensitive and stable hybrid surface-enhanced Raman scattering (SERS)-active substrates constructed with flower-like two-dimensional molybdenum sulfide and Ag (MoS2@Ag) has been developed, and then the above substrate was sequentially utilized in the recyclable detection of pesticide residues on several kinds of fruits and vegetables. In the first place, the excellent photocatalytic performance of the MoS2@Ag hybrid substrate was demonstrated, which was attributed to the inhibition of electron-hole combination after the formation of Schottky barrier between the Ag NPs and MoS2 matrix. Thereafter, two calibration curves with ultra-low limits of detection (LOD) as 6.4 × 10-7 and 9.8 × 10-7 mg/mL were established for the standard solutions of thiram (tetramethylthiuram disulfide, TMTD) and methyl parathion (MP), and then the recyclable assay of their single and mixed residues on eggplant, Chinese cabbage, grape, and strawberry was successfully realized. It is interesting to note that the detection recoveries from 95.5 to 63.1% for TMTD and 92.3 to 62.6% for MP are greatly dependent on the size and surface roughness of these foods. In a word, the MoS2@Ag composite matrix shows attractive SERS and photocatalysis performance, and it is expected to have the potential application on food safety monitoring.