Rubber Industry Research Articles

Advancing image segmentation with DBO-Otsu: Addressing rubber tree diseases through enhanced threshold techniques.

Addressing the profound impact of Tapping Panel Dryness (TPD) on yield and quality in the global rubber industry, this study introduces a cutting-edge Otsu threshold segmentation technique, enhanced by Dung Beetle Optimization (DBO-Otsu). This innovative approach optimizes the segmentation threshold combination by accelerating convergence and diversifying search methodologies. Following initial segmentation, TPD severity levels are meticulously assessed using morphological characteristics, enabling precise determination of optimal thresholds for final segmentation. The efficacy of DBO-Otsu is rigorously evaluated against mainstream benchmarks like Peak Signal-to-Noise Ratio (PSNR), Structural Similarity Index (SSIM), and Feature Similarity Index (FSIM), and compared with six contemporary swarm intelligence algorithms. The findings reveal that DBO-Otsu substantially surpasses its counterparts in image segmentation quality and processing speed. Further empirical analysis on a dataset comprising TPD cases from level 1 to 5 underscores the algorithm's practical utility, achieving an impressive 80% accuracy in severity level identification and underscoring its potential for TPD image segmentation and recognition tasks.

Methacrylic acid in situ modified steel converter slag/natural rubber composites: Resourceful utilization of steelmaking solid wastes

As a by-product of the steelmaking industry, the large-volume production and accumulation of steel converter slag cause environmental issues such as land occupation and dust pollution. Since metal salts of unsaturated carboxylic acid can be used to reinforce rubber, this study explores the innovative application of in-situ modified steel slag, mainly comprising metal oxides, with methacrylic acid (MAA) as a rubber filler partially replacing carbon black. By etching the surface of steel slag particles with MAA, their surface roughness was increased, and the chemical bonding of metal methacrylate salt was introduced to enhance their interaction with the molecular chain of natural rubber (NR). The results showed that using the steel slag filler effectively shortened the vulcanization molding cycle of NR composites. The MAA in-situ modification effectively improved the interaction between steel slag and NR molecular chains. Meanwhile, the physical and mechanical properties, fatigue properties, and dynamic mechanical properties of the experimental group with MAA in-situ modified steel slag (MAA-in-situ-m-SS) were significantly enhanced compared with those of NR composites partially filled with unmodified slag. With the dosage of 7.5 phr or 10 phr, the above properties matched or even exceeded those of NR composites purely filled with carbon black. More importantly, partially replacing carbon black with modified steel slag reduced fossil fuel consumption and greenhouse gas emission from carbon black production. This study pioneered an effective path for the resourceful utilization of steel slag and the green development of the steelmaking and rubber industries.

Investigation of Thermal Decomposition and Thermal Oxidative Degradation of a Composite of Cellulose Nanofibers and Deproteinized Natural Rubber Grafted Methyl Methacrylate

Natural rubber (NR) is a polymer that has many applications in daily life. However, the traditional rubber industry relies heavily on petroleum-based materials, causing environmental pollution problems. Therefore, to reduce environmental challenges, products created from NR are combined with non-toxic chemicals and natural fillers such as cellulose nanofibers (CNF). This study presents the effect of CNF on the thermal properties of novel composites made from CNF and deproteinized natural rubber grafted methyl methacrylate (DPNR-g-MMA) under air and nitrogen atmosphere. Graft copolymerization of MMA onto DPNR to produce DPNR-g-PMMA was performed in the latex phase. The CNF/DPNR-g-PMMA composite was created by dispersing CNF in DPNR-g-PMMA at ratios of 0.5%, 1%, and 1.5% using ultrasonic waves. DPNR-g-PMMA was employed as the composite's matrix and CNF served as its reinforcing phase. Fourier transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance spectroscopy (1H NMR) were used to confirm the success of the graft copolymerization. The thermal properties of materials were studied by Thermalgravimetric analysis (TGA) and Differential scanning calorimetry (DSC), in which the thermal stability of composites was examined via TGA under air and nitrogen atmosphere. The obtained data illustrate that, in comparison to DPNR and DPNR-g-PMMA, the decomposition temperature of all CNF/DPNR-g-PMMA composites, especially at CNF ratio of 1%. After blending CNF to DPNR-g-PMMA, the decomposition temperatures of CNF/DPNR-g-PMMA 1% increased by nearly 2 °C in nitrogen atmosphere and by 5.27 °C in air atmosphere. These results prove that the CNF is a key role in the thermal stability of DPNR-g-PMMA.

Rubber plantation size and global rubber price are linked to forest loss and degradation in Jambi, Sumatra

AbstractNatural rubber cultivation is one of the main drivers of tropical deforestation and biodiversity loss. This study examines regulatory and socio‐economic conditions that increase the susceptibility of rubber plantations to deforestation and degradation, aiming to support zero‐deforestation pledges and sustainability commitments made by the natural rubber industry. By combining bottom‐up socio‐economic survey data from rubber smallholder farmers in Indonesia with top‐down spatial datasets on forest loss and degradation, this study identifies factors associated with deforestation, tree cover loss, and degradation of high‐risk plantations. In Jambi Province, Indonesia, from 1991 to 2018, the overall tree cover loss in areas adjacent to rubber plantations was positively correlated to plantation size, remoteness (travel time to cities), and distance to the nearest protected areas, indicating that larger, remotely located plantations likely expanded more into forests between 2000 and 2018. Similarly, tropical forest degradation was positively associated with plantation size, travel time to cities, and distance to protected areas. A higher rubber price in the preceding year correlated with increased annual deforestation and forest degradation, whereas lower prices had the opposite effect. These results suggest that monitoring price changes and identifying plantations that are near non‐protected forest frontiers could enable early detection and potential mitigation of deforestation threats.

Preparation of multifunctional chitosan derivative containing 10-undecenoyl and galloyl groups and its application in styrene-butadiene rubber/silica composites

The traditional small molecular rubber antioxidants have the shortcomings of single function, toxicity, and heavy dependence on non-renewable fossil resources, which limits their green, high-efficiency, and sustainable development in the rubber industry. To address this problem, in this work, we first developed a chitosan derivative containing 10-undecenoyl groups (COS-UC) and then combined it with the natural small molecular antioxidant gallic acid (GA) to prepare chitosan derivative containing 10-undecenoyl and galloyl groups (COS-UC-GA). The obtained COS-UC-GA was used as multifunctional modifier and applied in styrene-butadiene rubber (SBR)/silica composites. The effects of COS-UC-GA on the curing characteristics, crosslinking density, morphology, mechanical properties, and interfacial interaction of SBR/silica composites were explored in detail. The results indicated that the COS-UC-GA can effectively accelerate the vulcanization process of SBR/silica compounds, promote the uniform dispersion of silica, improve the mechanical properties of SBR/silica composites, and significantly enhance the interfacial interaction between the silica and rubber. This research provides a new perspective for developing green and eco-friendly multifunctional modifiers, which not only contributes to the comprehensive utilization of biomass resources, but also can promote the green development of the rubber industry.

Nucleophiles realizing the reduction of ZnO content for vulcanization accompanied by the improvement in thermo‐oxidative resistance for vulcanized isoprene rubbers

AbstractAt present, vulcanization is an indispensable process in rubber industries and ZnO is an important ingredient in vulcanization reactions. However, ZnO is toxic to aquatic organisms and the use of ZnO is unfavorable to the sustainable development of rubber industry. The decrease of ZnO content without the reduction in properties of rubbers has been an open question in rubber industries. In this work, our group designs nucleophiles with an ability to open the ring of sulfur. With the decrease of ZnO content, the addition of nucleophiles maintains the ring‐opening capacity of sulfur. As a result, changes in several properties of rubbers such as tensile strength, tear strength, and crosslinking density are negligible with the reduction of ZnO content. Also, the thermo‐oxidative resistance of rubbers improves dramatically with the decrease of ZnO content and addition of nucleophiles. Through designing nucleophiles to reduce the content of ZnO, this work provides a strategy to develop sustainable rubber industries.

Study of BOD: COD Ratio as an Indicator for Wastewater of Rubber Industry Sector

When considering the rubber industry sector, the most significant challenge is the efficient wastewater treatment before discharging it into the natural environment. The rubber industry is considered to be highly chemical and water-intensive: and involves enormous quantitative s of waste production. The ratio between Biological Oxygen Demand (BOD5) and Chemical Oxygen Demand (COD) is a widely used parameter in characterising wastewater and then the same was used in this study as an indication to measure the efficiency of wastewater treatment plant operated in the rubber industry sector. Data for the study was extracted from samples collected from 10 wastewater treatment plants of rubber industries in the Sabaragamuwa Province; two samples from each representing before and after treatment. The samples were tested in two replicated for BOD5, COD, pH, and conductivity. These selected rubber factories contain lagoon/pond type wastewater treatment systems or activated sludge wastewater treatment systems. The results showed that the treated wastewater samples were within the range of 0.1–0.4 of BOD5: COD and were below the BOD5: COD permissible level as per CEA standards. (General standards for rubber in inland surface waters; Latex-BOD 60, COD 400; Lanka rubber/crepe rubber–BOD 50, COD 400) comparing the BOD, COD, pH, and conductivity influent and effluent of the treatment process proves the effectiveness of each treatment plant of the relevant industry. Tested samples show a high BOD5: COD ratio in influent and effluent of wastewater treatment system indicate that wastewater of the industry is easily biodegradable. However, more research comparing the characteristics of different rubber manufacturing processes is needed to develop this approach further. 
 Keywords: BOD, COD, BOD: COD ratio, Wastewater treatment plant

Performance of Full-Component Coal Gasification Fine Slag: High-Value Utilization as Reinforcing Material in Styrene-Butadiene Rubber (ESBR) for Replacing Carbon Black.

Ultrafine, highly active coal gasification slag (HCGS) was produced via a sustainable, green dry-ball-milling method. Coal gasification fine slag (CGS), a potential environmental pollutant, was used as a new source of rubber filler without pre-treatment, enabling waste utilisation. HCGS was added to styrene-butadiene rubber (ESBR) composites, and the effects of HCGS and the filler content on the mechanical and thermal stabilities of SBR were evaluated. The procedure conforms to important green metrics, requiring no solvent or additional reagent, or solvent-assistance for product collection. HCGS reduced the scorch time (t10) and curing time (t90) of the filled ESBR composites relative to those of pure SBR and improved the mechanical parameters. The tensile strength at 50 phr reached 10.91 MPa, and the tear strength at 90 phr reached 64.92 kN/m, corresponding to 9.4- and 3.92-fold increases relative to that of SBR filled with HCGS, respectively. HCGS exerted a reinforcing effect on ESBR, comparable to that of commercial carbon black (CB) N330. HCGS improves the binding between rubber molecules and filler particles and captures the rubber chain, thereby limiting its movement. HCGS is potentially applicable as a CB substitute in the rubber industry, with environmental and economic benefits in the disposal of CGS.

Pengenalan Segmentasi Pasar Demi Meningkatkan Wawasan Petani Karet Di Desa Parsarmaan

Objektif. Rubber is the main commodity developed in Parsarmaan Village, and to optimize their production results, as well as increase the sustainability of the rubber industry, a better understanding of the market is very important. Market segmentation is a strategy that can help rubber farmers understand the characteristics and needs of their diverse customers. This article outlines the reasons why market segmentation is necessary and how rubber farmers can implement it effectively. Through demographic, geographic analysis and the use of technology, rubber farmers can collect data about their customers. With this data, they can customize their products, services and their marketing strategies to achieve greater success. The benefits of introducing market segmentation for rubber farmers include increased sales, business sustainability, innovation, economic prosperity, and verified. With a better understanding of different market segments, rubber farmers can increase their income, strengthen the rubber industry, and improve their own quality of life. With a continued commitment to understanding their customers and following the right approach, rubber farmers in Parsarmaan Village have a great opportunity to achieve long-term success in their rubber industry. Market segmentation is an important tool that can help them achieve their goals.Materials and Methods. To achieve the expected goals, the Parsarmaan Village KKN program was carried out using the PAR method. PAR is an abbreviation for Participatory Action Research. Basically, PAR is research that involves all relevant parties in actively researching together current actions (which they experience as problems) in order to change and improve them. In this service, a participatory approach is used to involve local communities in the outreach process. Results. The result of this service for the community is that the community understands market segmentation better, rubber farmers can increase sales and increase the economic welfare of the community. Apart from that, the introduction of market segmentation not only provides more insight into customers, but also opens up opportunities for growth and development of the rubber industry. Conclusion. The introduction of market segmentation is a crucial step in efforts to increase the insight of rubber farmers in Parsarmaan Village. Rubber farmers through the introduction of market segmentation have great potential for success, namely increasing sales, business sustainability, increasing economic welfare, and opportunities for diversification. By focusing on various existing segments, they can achieve great success in the changing rubber industry

Effective Usage of GIS and Remote Sensing for Sustainable Development of Rubber Industry

Background/Purpose: All nations, developed or developing, place the greatest emphasis on agricultural sustainability. In order to manage and produce agriculture sustainably, remote sensing based and geographical information system (GIS) technique is becoming increasingly significant instruments. In this work, we examine the integrated application of RS and GIS technology in various locations for sustainable agricultural growth and management of Rubber Industry in India. Remote sensing and Geographical Information System (GIS) are the most recent technologies or support systems or tools that will generate much more accurate results and conduct various geographic analyses even in the most complex situations. Objective: Using various studies as case studies, this paper examines the various ways in which the natural rubber industry and cultivation area can be improved using GIS and remote sensing technology. Design/Methodology/Analysis: Using the ABCD analysis, data from scholarly papers, online articles, and other sources are analyzed and presented. Additional sources are used to collect inputs for the case study, mainly include specific reports, circular and Rubber science magazine articles. Findings/Result: This paper examines the areas in which the Natural Rubber industry can be improved using GIS and Remote sensing technology. Traditionally, human-centered land survey, soil survey, Rubber area survey, Plant disease diagnosis, soil mineral survey etc.were very time consuming and expensive. Using GIS & RS field, we are able to overcome these shortcomings. Originality Value: This research investigates the various applications of GIS and RS, which aids in the development of the natural rubber industry. Type of Paper: Industry Analysis-based Research Case Study.

Evaluation of Four Yield Stimulants on Hevea brasiliensis Yield

Latex yield stimulants, such as ethephon (2-chloroethylphosphonic acid), are widely utilised in the rubber industry to extend latex flow, ultimately improving latex yield. In this study, which lasted 44 months, the efficacy of three promising liquid stimulants (referred to as Products A, B, and D) was compared with Product C which is the common stimulation product used currently. Overall, all tested latex stimulation products demonstrated the ability to increase latex yield per tapping by 75 to 89 grammes per tree per tapping (g/t/t) or 50 to 78 per cent during the months of stimulation. However, on a long-term basis, when the yields of stimulated and non-stimulated (wintering) months were taken into account, the yield per tapping of stimulated trees increased by 11 to 18 g/t/t or 32 to 51 per cent. Notably, Product A, when applied three times a month, showed the highest incidence of tapping panel dryness (TPD) compared to the Control and Product D treatments, where no TPD was observed. The cost-benefit analysis showed that Product C was the most economically viable option, costing only RM 0.10 per kilogramme of latex yield, in contrast to the other stimulants, which ranged from RM 0.19 to RM 2.15 per kilogramme of latex yield. Keywords: Natural rubber, panel dryness, rubber production, latex yield stimulants.

Swelling of rubbers of different chemical natures in supercritical carbon dioxide

Objectives. To investigate the swelling of the main types of rubbers used in the rubber industry in carbon dioxide in a supercritical state (SC-CO2), in order to assess the possibility of obtaining elastomeric materials with porous structures using fluid technology, based on them.Methods. The process of swelling of rubbers in SC-CO2 and subsequent foaming was carried out according to a specially developed technique using the original installation. This is a high-pressure apparatus with transparent windows, allowing for the use of an optical technique to directly measure the geometric dimensions of samples during swelling and foaming using a digital video camera. The study of the porous structure of foamed rubbers was carried out using scanning electron microscopy.Results. The study established experimental curves of the swelling kinetics in SC-CO2 of isoprene, butadiene, styrene butadiene, ethylene propylene, chloroprene, ethylene acrylate, siloxane, and organofluorine rubbers. The influence of temperature and pressure on the rate and equilibrium degree of swelling was studied. The diffusion coefficients of SC-CO2 in rubbers of various chemical natures were also determined.Conclusions. It was shown that the equilibrium swelling degree of rubbers in SC-CO2 depends on the chemical nature of rubbers. It does not correlate with the value of their solubility parameters, changes directly proportional to the diffusion coefficient and increases with increasing temperature and pressure. It was found that irrespective of the degree of swelling in SC-CO2, all the rubbers studied are intensively foamed at a sharp pressure drop. The size of the pores formed is tens of microns: significantly smaller than the size of pores formed when chemical pore formers are used.

Preparation and Characterization of Activated Palm Kernel Shell/Carboxylated Nitrile Butadiene Rubber (APKS/XNBR) Vulcanizate

Malaysia is one of the most important palm oil producers and exporters in the whole wide world. There has been a rapid development of new palm oil plantations and palm oil mills in this country. The palm oil industry plays a vital role in the economic growth of Malaysia. However, as the palm oil industry grows bigger and wider, a huge amount of palm oil waste is produced which is an alarming issue considering it can cause pollution and have a negative effect on the environment. Raw Palm Kernel Shell (PKS) derived from palm oil waste can be converted into Activated Palm Kernel Shell (APKS) which has the potential to be a value-added biofiller in rubber vulcanizates. Thus, in this study, APKS is prepared through a carbonization process at a temperature of 900 °C and an activation process via steam treatment and used as filler in Carboxylated Nitrile Butadiene Rubber (XNBR). The aim of this study is to evaluate the influence of different loading ratios of APKS on theswelling index measurement, bound rubber content (BRC), abrasion resistance, compression set, and hardness of XNBR vulcanizates. APKS is incorporated in XNBR at different loading ratios, ranging from 0 to 50 phr and these APKS-filled XNBR vulcanizates are prepared with a two-roll mill. The overall physico-mechanical properties of APKS-filled XNBR vulcanizates showed increment in terms of BRC, compression set, and hardness as the loading ratio of APKS increased. XNBR vulcanizates with a higher loading ratio of APKS also showed a decrease in swelling index measurement and volume loss which would indicate high abrasion resistance. These results could be attributed to the porosity of APKS as shown in the morphological analysis which provided a high surface area of contact for crosslinking and mechanical interlocking. This proves APKS could potentially be a semi-reinforcing filler for rubber vulcanizates, especially for XNBR vulcanizates as XNBR vulcanizates were able to achieve high abrasion resistance and high hardness with the incorporation of APKS. With this, the conversion of PKS into APKS could help to reduce palm oil waste and provide an environmentally friendly, sustainable biofiller option to rubber researchers and manufacturers who are looking for an alternative to petroleum-based fillers. This would be very beneficial for both the palm oil industry and the rubber industry.

Recent Developments in Synthesis, Properties, Applications and Recycling of Bio-Based Elastomers.

In 2021, global plastics production was 390.7 Mt; in 2022, it was 400.3 Mt, showing an increase of 2.4%, and this rising tendency will increase yearly. Of this data, less than 2% correspond to bio-based plastics. Currently, polymers, including elastomers, are non-recyclable and come from non-renewable sources. Additionally, most elastomers are thermosets, making them complex to recycle and reuse. It takes hundreds to thousands of years to decompose or biodegrade, contributing to plastic waste accumulation, nano and microplastic formation, and environmental pollution. Due to this, the synthesis of elastomers from natural and renewable resources has attracted the attention of researchers and industries. In this review paper, new methods and strategies are proposed for the preparation of bio-based elastomers. The main goals are the advances and improvements in the synthesis, properties, and applications of bio-based elastomers from natural and industrial rubbers, polyurethanes, polyesters, and polyethers, and an approach to their circular economy and sustainability. Olefin metathesis is proposed as a novel and sustainable method for the synthesis of bio-based elastomers, which allows for the depolymerization or degradation of rubbers with the use of essential oils, terpenes, fatty acids, and fatty alcohols from natural resources such as chain transfer agents (CTA) or donors of the terminal groups in the main chain, which allow for control of the molecular weights and functional groups, obtaining new compounds, oligomers, and bio-based elastomers with an added value for the application of new polymers and materials. This tendency contributes to the development of bio-based elastomers that can reduce carbon emissions, avoid cross-contamination from fossil fuels, and obtain a greener material with biodegradable and/or compostable behavior.

Optical fiber gas sensor with multi-parameter sensing and environmental anti-interference performance

Formic acid finds widespread applications in numerous fields, including the petrochemicals production, rubber industry, and leather tanning process, in which the operational environments are complex and diverse. The corresponding industrial systems are often intricate and highly integrated. Indeed, formic acid gas is insidious and poses a hazard to both operating personnel and industrial equipment. The existing detection technologies for formic acid gas suffer from inherent technical limitations, making it challenging to effectively shield against industrial interference in complex environments while accurately conveying information. Furthermore, the simultaneous transmission of essential environmental data alongside formic acid gas concentration remains a formidable challenge, which is crucial for facilitating the integration and simplification of industrial system. In response to the aforementioned challenges, this research firstly employs an optical fiber structure (SNS: single mode fiber-no-core fiber-single mode fiber) with natural resistance to electromagnetic interference as the substrate. Subsequently, considering the characteristics of spectral variations and the response mechanism of formic acid gas, and addressing the issue of humidity interference of the current-stage sensors based on sensitive material, the chitosan and chitosan@PDMS are chosen as sensitive membranes. Finally, a correction formula was introduced to address the temperature and humidity coupling issue of the sensor, resulting in the successful development of two formic acid gas sensors. The chitosan-based sensor has a detection sensitivity of up to 7.7 pm/ppm, whose dual parameter detection performance for temperature and formic acid gas has been experimentally demonstrated. It can also correct the humidity-induced detection error in real-time by the correction formula. The chitosan@PDMS-based sensor was fabricated by plating a hydrophobic and breathable PDMS membrane on the surface of the chitosan-based sensor. In addition to maintaining the performance compared to the original sensor (response and recovery time was increased), the latter sensor can effectively resist the humidity interference from the environment. Furthermore, the new capability has been complemented for the simultaneous detection of temperature and humidity. That is, it realizes the dual parametric detection for formic acid gas and humidity, meanwhile providing the compensation ability for temperature change. The proposed sensors have the outstanding sensitivity, selectivity, immunity, and safety. This research not only effectively resolves the interference problem in formic acid gas detection, but also provides a new idea for equipment simplification and information integration in complex industrial systems.

Certified Reference Material for the Composition of Phthalates in a Polymer Matrix Based on Polyvinyl Chloride

The purpose of the study was to develop a new CRM for the composition of the mass fraction of phthalates in a polymer matrix based on polyvinyl chloride for validation and/or verification of measurement methods such as GOST R ISO 8124-6-2021, GOST R ISO 14389–2016, GOST R ISO 16181–2015 etc. In the study, a method for preparing the starting material of the CRM was tested and successfully implemented, and a critical analysis of methods for measuring the content of di(n-butyl)phthalate and di(2-ethylhexyl)phthalate was carried out. The gas chromatography/isotope dilution mass spectrometry method was chosen as the main method for a quantitative determination of the certified value of the measured value of the mass fraction of di(n-butyl)phthalate and di(2-ethylhexyl) phthalate. In accordance with RMG 93–2015, GOST 8.315-2019, and GOST ISO Guide 35–2015, the standard uncertainty of the certified CRM value from the characterization method, from heterogeneity and instability of the material was assessed. The expanded uncertainty of the certified value was calculated. As a result of the work, a new CRM for the composition of the mass fraction of phthalates in a polymer matrix based on polyvinyl chloride was approved. Certified CRM values are metrologically traceable to GET 208 in accordance with metrological hierarchy according to the verification schedule through GSO 11366–2019. A CRM composition for the mass fraction of phthalates in polyvinyl chloride has the following standardized metrological characteristics: mass fraction of di(n-butyl)phthalate – 0.046 mg/g and di(2-ethylhexyl)phthalate – 45.8 mg/g; the relative expanded uncertainty at k = 2, P = 0.95 is 10 %. The CRM is stored in sealed bottles in a dry place, protected from light, at a temperature from 2 °C to 8 °C. The shelf life of the CRM is 3 years. The developed CRM can be used in solving any measurement problems and performing various types of metrological work, including metrological purposes in the field of polymer and rubber industries, food industry, environmental protection, and scientific research.

Ligand-binding properties of XaffOBP9, a Minus-C odorant-binding protein from Xyleborus affinis (Coleoptera: Curculionidae: Scolytinae).

Xyleborus affinis, one of the most important pests of rubber trees, has caused severe damage to the natural rubber industry in Hainan province. The ability to detect host plants through a sensitive and specific olfactory system is crucial for Xyleborus affinis. Odorant binding proteins (OBPs) are believed to bind and carry hydrophobic active compounds from the environment to the surface of olfactory receptor neurons. To investigate the potential functional role of the highly expressed XaffOBP9 in binding with semiochemicals, we cloned and analyzed the cDNA sequence of XaffOBP9. The results showed that XaffOBP9 contains a 411bp open reading frame that encodes 136 amino acids. Then XaffOBP9 was expressed in Escherichia coli. The binding affinity of the recombinant OBP to 15 different ligands (14 host plant volatiles and 1 aggregation pheromone) was then examined using a fluorescence competitive binding approach. The results demonstrated that XaffOBP9 exhibited broad binding capabilities and strong affinities for 14 ligands. The structure of XaffOBP9 and its interactions with fourteen ligands were further analyzed by modeling and molecular docking, respectively. Based on the docking result, we found hydrophobic interactions are important between XaffOBP9 to these ligands and three amino acid residues (L71, Y106, and L114) were highly overlapped and contributed to the interaction with ligands. Mutation functional assays confirmed that the mutant L114A showed significantly reduced binding capacity to these ligands. This study suggested that XaffOBP9 may be involved in the chemoreception of semiochemicals and that it is helpful for the integrated management of X. affinis.

INCREASING THE DURABILITY OF PAVEMENT ON REINFORCED CONCRETE ROAD BRIDGES

Summary. Highway bridges are an important part of the transportation infrastructure, as they ensure the uninterrupted movement of vehicles and cargo. Due to the peculiarities of asphalt pavement operation on bridges with reinforced concrete roadway slabs, as well as the negative impact of weather conditions and the use of deicing materials, such pavement is more often subject to defects. In order to minimize pavement damage on road bridges and increase their durability, it is necessary to improve certain aspects of conventional asphalt mixtures, such as rutting and cracking resistance. Today, one of the methods to ensure increased durability of asphalt pavements is to modify asphalt mixtures or bituminous binders. The use of asphalt concrete pavements with increased durability is an effective method to increase the overhaul period and, as a result, reduce the cost of maintenance of road bridges. And the use of asphalt mixtures modified with rubber crumb will provide a partial solution to the environmental problem, such as the accumulation of waste from the rubber industry. Keywords: road bitumen, bitumen binder modification, asphalt concrete, asphalt mixtures.

Exploration of Green Alternatives to 6PPD (P-Phenylenediamine) Used as Antiozonant and Antioxidant in the Rubber Industry

Exploration of Green Alternatives to 6PPD (P-Phenylenediamine) Used as Antiozonant and Antioxidant in the Rubber Industry

An Overview of Green Applications of Natural Products for Pharmaceutical, Biofuel, and Rubber Industries: Case Study of Kazakh Dandelion (Taraxacum kok-saghyz Rodin.)

An Overview of Green Applications of Natural Products for Pharmaceutical, Biofuel, and Rubber Industries: Case Study of Kazakh Dandelion (Taraxacum kok-saghyz Rodin.)