Production Of Polymers Research Articles

Telechelic Dithiol Copolymers as Tunable Building Blocks for Synthesizing Multiblock Materials

ABSTRACTA new strategy is reported to access α,ω‐dithiol polymer building blocks with tunable molecular weights and compositions for the preparation of random multiblock copolymers based on styrenic, acrylic, and siloxane repeat units. This facile synthetic approach provides access to dithiols through a two‐step process: (1) an initial copolymerization of vinyl monomers with ethyl lipoate followed by (2) disulfide bond reduction, producing dithiol terminated polymer products. Thiol‐terminated polymers are easily prepared over a wide range of molecular weights (2–32 kDa) by simply controlling the feed ratio of vinyl monomer to ethyl lipoate. Mixtures of these linear dithiol‐terminated building blocks were repolymerized via oxidative coupling to create random multiblock copolymers with high molecular weights (68–95 kDa) and controlled degradability. In summary, this approach for preparing and recombining telechelic dithiol polymers creates opportunities to manipulate the mechanical and physical properties of multiblock copolymers using a synthetically simple and versatile platform.

Improving Fire Retardance Properties of Polymer Fiber Materials and Products

Improving Fire Retardance Properties of Polymer Fiber Materials and Products

Scalable Nickel Catalysts for Carbonylative Terpolymerization of Ethylene/α-Olefin with High Efficiency.

The carbonylative polymerization of olefin yields aliphatic polyketones, which are used as engineering plastics in the market due to their excellent mechanical strength, chemical resistance, and surface and barrier properties. However, the usage of precious palladium catalysts has restricted their extensive application as commodity materials. Herein, we present a series of phosphine-sulfonate Ni catalysts with a wide spectrum of electronic and steric substituents on the phosphorus moiety for the carbonylative polymerization of ethylene. Such efficient nickel-catalyzed copolymerization shows the on-demand transformation of ethylene/CO gas to polyketones with quantitative yield and product specificity. A remarkable productivity of up to 20 kg PK (g Ni)-1 was obtained during ethylene/propylene/CO terpolymerization, and the polymerization productivity is independent of the type and feeding amount of α-olefin. The resulting terpolymers show comparable crystallinity, thermal stability, and tensile properties with commercial POKETONE products from Hyosung. The nickel catalyst also features the advantages of using cheap raw material sources and simple synthetic procedures that can be scaled up easily, which enables it to be a promising candidate for industrial application.

Prediction of the thermal degradation–induced colour change of acrylonitrile butadiene styrene products as a function of temperature and titanium dioxide content

In this study, we examined the thermal degradation–induced colour change of acrylonitrile butadiene styrene (ABS)–based titanium dioxide (TiO2)–doped products as a function of TiO2 content and temperature. Based on the time–temperature superposition (tTS) principle and the CIELAB colour space, we proposed a methodology for developing a robust model to estimate the long-term colour change of polymers doped with TiO2 at elevated temperatures. We used 800 h of measurement data to develop the model and validated the colour change predictions of the model in 1600 h. The average colour difference between the measured and modelled results at the application temperature range (below 80 °C) was <1.5, smaller than the just noticeable difference (JND) in the CIELAB colour space. We found that above a certain TiO2 content (approximately 3 wt%), the colour retention of the ABS/TiO2 specimens can no longer be improved by increasing their TiO2 content. To show the applicability of the model, we present two simple case studies predicting the colour and appearance of a polymer product under constant and variable heat loads. The proposed methodology provides an excellent tool for design, as it can be used to determine the optimum amount of TiO2. Moreover, it accelerates and simplifies the design process.

Development of a Cloud Service for Comprehensive Research of Polymer Synthesis Processes

The issue of digitalization in chemical technology production is currently quite pressing, and the available computational infrastructure is insufficient for assessing the technological properties of the products obtained through mathematical modeling tools. This problem is particularly relevant for polymer synthesis processes, where standard empirical evaluations require enormous computational resources, and existing methods and algorithms prove ineffective when organizing multiple computational trials to select optimal production scenarios. The aim of this study is to develop a cloud-based digital service that enables comprehensive research into complex physicochemical processes occurring via polymerization mechanisms. The implementation of all algorithms is based on the use of kinetic and statistical approaches to modeling, and the embedded calculation methods are adapted to the specifics of polymerization processes. The conceptual framework of the developed cloud service is represented by a three-tier network architecture, and the established mechanism of network interaction allows the service to operate in a 24-hour multi-user mode. Task execution in the remote environment and the distribution of computational resources are handled using Docker containerization technology, which provides software-level virtualization within the operating system. The storage subsystem is managed by the MongoDB database management system, which supports distributed information storage functions. The organization of test computational experiments in evaluating the detailed properties of polymer products allowed for the assessment of the system’s core logic in web interface mode and the adequacy of the obtained calculation results. Doi: 10.28991/ESJ-2024-08-06-023 Full Text: PDF

Creep characterisation and microstructural analysis of municipal solid waste incineration fly ash geopolymer backfill

In this work, an alkali-activated municipal solid waste incineration (MSWI) fly ash-based filling material was prepared with MSWI fly ash as the raw material and slag as the auxiliary material. The filling body experiences long-term creep, which may have a direct effect on the stability of the overlying strata of the mine goaf. The long-term mechanical properties of the fly ash-based filling materials were tested with a triaxial rheological apparatus. First, uniaxial creep testing was carried out at five levels of axial stress: 50%, 60%, 70%, 80% and 90% of the uniaxial compressive strength (UCS). Then, triaxial creep testing was carried out by considering the geological environment of the goaf. The creep characteristics of fly ash-based filling materials under a three-dimensional stress state were explored. The results indicate that (1) under different stress levels, the creep curves of fly ash-based filling materials can be divided into three types: decelerated creep‒stable creep, decelerated creep‒constant creep, and decelerated creep‒constant creep‒accelerated creep. (2) The total creep deformation of the fly ash-based filling material is 0.46 ~ 0.78%, which is similar to the creep deformation of soft rock. The instantaneous deformation during loading contributes most of the total deformation. (3) The polymerization products generated in the fly ash-based filling material system can effectively cement the raw material particles, and the presence of gel can effectively delay the accelerating creep process of the material. (4) A nonlinear fractional-order model composed of an Abel dashpot can fully describe the complete process of decelerating creep-constant creep-accelerating creep.

Electric stimulation: a versatile manipulation technique mediated microbial applications.

Electric stimulation (ES) is a versatile technique that uses an electric field to manipulate microorganisms individually. Over the past several decades, the capabilities of ES have expanded from bioremediation to the precise motion control of cells and microorganisms. However, there is limited information on the underlying mechanisms, latest advancement and broader microbial applications of ES in various fields, such as the production of extracellular polymers with upgraded properties. This review article summarizes recent advancements in ES and discusses it as a unique external manipulation technique for microorganisms with wide applications in bioremediation, industry, biofilm deactivation, disinfection, and controlled biosynthesis. One specific application of ES discussed in this review is the extracellular biosynthesis, regulation, and organization of extracellular polymers, such as bacterial cellulose nanofibrils, curdlan, and microbial nanowires. Overall, this review aims to provide a platform for microbial biotechnologists and synthetic biologists to leverage the manipulation of microorganisms using ES for bio-based applications, including the production of extracellular polymers with enhanced properties. Researchers can engineer, manipulate, and control microorganisms for various applications by harnessing the potential of electric fields.

The influence of pH on the liquid-phase transformation of phenolic compounds driven by nitrite photolysis: Implications for characteristics, products and cytotoxicity

The aqueous-phase conversion of phenolic compounds (PhCs) driven by nitrite photolysis has been recognized as a significant source of secondary brown carbon (BrC). However, the influence of pH on the conversion kinetics and product distribution of PhCs remains unclear. In this study, three representative PhCs with varying functional groups were selected to examine their aqueous-phase conversion kinetics in the presence of nitrite under different pH conditions and simulated sunlight conditions. The results indicate that as the pH increases, the decay rates of PhCs decrease, following first-order reaction kinetics. These varying decay rates also suggest that different substituents on the benzene ring significantly impact the reactivity of PhCs. The molecular composition of the products is pH-dependent, with 4-nitrocatechol (4NC) emerging as the primary reaction product. A range of conversion products were detected across different pH values: nitrification dominated at low pH, while hydroxylation products increased with rising pH, and polymerization products appeared prominently at high pH. Due to the electron-withdrawing effect of the nitro group on the benzene ring, fewer products formed from 4-nitrophenol were observed, and the visible absorption spectrum also showed a decreasing trend as the reaction progressed across various pH conditions. Toxicity assays on human non-small cell lung cancer cells (A549) revealed that the toxicity of the reaction products decreased with increasing pH. Correspondingly, the accumulation of reactive oxygen species (ROS) and apoptosis rates in cells also declined. This may be due to the fact that at lower pH levels, nitrophenols (NPs), which tend to promote ROS accumulation and cell death, dominate the product mix. This study provides valuable insights into the toxicological properties of secondary organic aerosols (SOA) formed from the photo-oxidation products of PhCs under different pH conditions. These findings contribute to a deeper understanding of the environmental and health impacts of SOA in atmospheric chemistry.

A benchmark of industrial polymerization process for thermal runaway process monitoring

Polymer production is of paramount importance in the chemical manufacturing industry. However, safety concerns are prevalent due to the exothermic nature of polymerization reactions, which can cause thermal runaway. The limitations of the current industry-standard monitoring methods underscore the need for novel techniques to detect faults early. To facilitate the development and evaluation of such algorithms, benchmarks that enable direct comparisons of performance are required. Addressing this gap, the present work first introduces an open-source polymerization benchmark model and associated datasets. Derived from reaction kinetics, mass balance, and energy balance analysis, the differential equation forms the basis of our model. By manipulating relative parameters, we intentionally induce five typical faults that can lead to thermal runaway. As a result, our benchmark model serves as an invaluable tool for advancing and validating algorithms for thermal runaway process monitoring, significantly enhancing the safety of the polymerization process. The effectiveness of the model and dataset is demonstrated by testing multivariate statistical process monitoring algorithms and deep learning algorithms.

Advances in radical peroxidation with hydroperoxides.

Organic peroxides have become sought-after functionalities, particularly following the multi-tone consumption in polymer production and success in medicinal chemistry. The selective introduction of a peroxide fragment at different positions on the target molecule is a priority in the modern reaction design. The pioneering Kharasch-Sosnovsky peroxidation became the basic universal platform for the development of peroxidation methods, with its great potential for rapid generation of complexity due to the ability to couple the resulting free radicals with a wide range of partners. This review discusses the recent advances in the radical Kharasch-type functionalization of organic molecules with OOR fragment including free-component radical couplings. The discussion has been structured by the type of the substrate of radical peroxidation: C(sp 3 )-H substrates; aromatic systems; compounds with unsaturated C-C or C-Het bonds.

Isoselective Polymerization of 1‐Vinylcyclohexene (VCH) and a Terpene Derived Monomer S‐4‐Isopropenyl‐1‐vinyl‐1‐cyclohexene (IVC), and Its Binary Copolymerization with Linear Terpenes

AbstractThe advancement of stereoregular polymerization techniques for linear 1,3‐dienes has enabled the production of polymers with precise stereocontrol, influencing their physical and chemical properties significantly. While 1,3‐butadiene and isoprene yield diverse stereoregular polymers, cyclic dienes have received less attention due to catalyst challenges and limited application in the rubber industry. However, the growing interest in bio‐based monomers, particularly those derived from terpenes and terpenoids, has revitalized interest in cyclic monomers with conjugated double bonds. This study investigates 1‐vinylcyclohexene (VCH) polymerization using [OSSO]‐type titanium complexes 1–2, revealing significant regio‐ and stereoselectivity. Catalyst 2, incorporating cumyl substituents, demonstrates superior performance, yielding highly isotactic poly(VCH) with 3,4‐insertion predominance. It is also shown that the polymerization of S‐4‐isopropenyl‐1‐vinyl‐1‐cyclohexene (IVC), a bio‐based monomer, results in a highly isotactic polymer. Finally, the copolymerization results of IVC with two linear terpenes to obtain copolymers derived entirely from renewable sources are also reported.

Selenium ameliorates oxidized phospholipid-mediated testicular dysfunction and epididymal sperm abnormalities following Bisphenol A exposure in adult Wistar rats

Bisphenol A (BPA) is an endocrine-disrupting compound extensively utilized in the production of polycarbonate polymers and epoxy resins that, upon exposure, pose a significant threat to male reproductive health because of its estrogenic properties. Accumulating evidence suggests that BPA exposure disrupts the normal process of spermatogenesis, alters testicular morphology and function, and interferes with testicular steroidogenesis and hormonal signaling. However, the precise mechanism by which BPA affects testicular function remains unclear. In this study, we explored the mechanism underlying BPA-induced testicular abnormalities and evaluated the protective effects of Selenium (Se). Thirty-two adult male albino Wistar rats were divided into four groups, and BPA was administered at 50 mg/kg body weight, with or without Se supplementation, for 30 days. Se supplementation (2.5 mg/kg body weight) was initiated 1 week before BPA administration. BPA administration resulted in alterations in testicular architecture, characterized by basement membrane disintegration in the seminiferous tubules, reduced spermatogenic cell counts, and increased interstitial tubule noncellular space. Furthermore, BPA exposure increased the levels of oxidized phospholipids, lipid peroxides, and hydroxyl radicals and decreased the activities of the antioxidant enzymes superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase. In addition, BPA significantly reduced the activities of 3β- and 17β-hydroxysteroid dehydrogenases, interfering with testicular steroidogenesis. In rats, coadministration of Se and BPA reduced the levels of oxidized phospholipids and increased the activities of antioxidant enzymes, leading to improved testicular function and epididymal sperm parameters, suggesting that Se plays a critical role in alleviating endocrine disruptor-induced testicular dysfunctions in rats.

Composition and polymerisation products influence on the viscosity of coal tar wash oil

Wash oil is a fraction obtained by the distillation of coal tar and is primarily used for the absorption of light oil from coke oven gas. During operation, the oil undergoes polymerization and loses some components, necessitating the removal of the used oil and its replacement with fresh wash oil. The rheological properties of the studied oils were determined using a Brookfield DV2T rotational controlled-shear rate rheometer. Gas chromatographic analysis, gas chromatography/mass spectrometry, and IR spectroscopy were employed to evaluate the oil’s characteristics. By adding individual components to the wash oil, it was found that these components could be categorized into three groups: viscosity enhancers, viscosity reducers, and non-polar oil substances with medium molecular weight that have no significant effect on viscosity. The addition of relatively polar components with greater molecular weight and a planar, rigid structure leads to an increase in viscosity. Conversely, the incorporation of naphthalene and its methyl homologues, which have lower molecular weights, reduces viscosity by disrupting intermolecular interactions; their lower heats of crystallization also inhibit the formation of structured order in the liquid, further contributing to the reduction in viscosity. The most substantial increase in oil viscosity was observed with the addition of indene-coumarone resins, attributed to their high molecular weight and polymer structure.

High-Strength, Self-Healing Copolymers of Acrylamide and Acrylic Acid with Co(II), Ni(II), and Cu(II) Complexes of 4'-Phenyl-2,2':6',2″-terpyridine: Preparation, Structure, Properties, and Autonomous and pH-Triggered Healing.

The utilization of self-healing polymers is a promising way of solving problems associated with the wear and tear of polymer products, such as those caused by mechanical stress or environmental factors. In this study, a series of novel self-healing, high-strength copolymers of acrylamide, acrylic acid, and novel acrylic complexes of 4'-phenyl-2,2':6',2″-terpyridine [Co(II), Ni(II), and Cu(II)] was prepared. A systematic study of the composition and properties of the obtained polymers was carried out using a variety of physicochemical techniques (elemental analysis, gel permeation chromatography (GPC), attenuated total reflectance Fourier transform infrared spectroscopy (ATR/FT-IR), ultraviolet-visible spectroscopy (UV-vis), small-angle X-ray scattering (SAXS), wide-angle X-ray scattering (WAXS), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA), confocal laser scanning microscopy (CLSM), and tensile testing). All metallopolymer samples exhibit autonomous intrinsic healing along with maintaining high tensile strength values (for some samples, the initial tensile strength exceeded 100 MPa). The best values of healing efficiency are possessed by metallopolymers with a nickel complex (up to 83%), which is most likely due to the highest lability of the metal-heteroatom coordination bonds. The example of this system shows the ability to re-heal with negligible deterioration of the mechanical properties. The possibility of tuning the mechanical properties of self-healing films through the use of different metal ions has been demonstrated.

Electrochemical Hydrodimerization of Lignocellulose-Derived Carbonyls in Aqueous Electrolytes for Biobased Polymer and Long-chained Synfuel Production: A Review.

The transformation from fossil resources, crude oil and natural gas to biomass-derived feedstocks is an urgent and major challenge for the chemical industry. The valorization of lignocellulose as renewable resource is a promising pathway offering access to a wide range of platform chemicals, such as vanillin, furfural and 5-HMF. The subsequent conversion of such platform chemicals is one crucial step in the value-added chain. The electrochemical hydrodimerization (EHD) is a sustainable tool for C-C coupling of these chemicals to their corresponding hydrodimers hydrovanilloin, hydrofuroin and 5,5'-bis(hydroxymethyl)hydrofuroin (BHH). This review covers the current state of art concerning the mechanism of the electrochemical reduction of biobased aldehydes and studies targeting the electrochemical production of these hydrodimers in aqueous media. Moreover, the subsequent conversion of these hydrodimers to valuable additives, polymers and long carbon chain synfuels will be summarized offering a broad scope for their application in the chemical industry.

Correlating Heterogeneities in Support Fragmentation to Polymer Morphology in Metallocene‐Based Propylene Polymerization Catalysis

AbstractIn the field of olefin polymerization catalysis, metallocenes are heterogenized with methylaluminoxane onto silica supports to yield active catalysts. During olefin polymerization, these silica supports act as a framework to control the fragmentation stage, thereby influencing the final polymer product and preventing reactor fouling and fines formation. This study investigates the influence of different silica supports induced on the final polymer product. To study a broad range of silica supports from an industrial silica database, we utilize a hierarchical clustering method to cluster the supports based on their physical properties. From the clustering method, five supports representing the clusters and an industrial benchmark were analyzed at different polymerization stages using focused ion beam–scanning electron microscopy (FIB–SEM) and microcomputed tomography (microCT). This combined FIB‐SEM/microCT methodology revealed differences in both fragmentation behavior and polymer morphologies based on structural features, including macropores, mesopores, spray‐dried shells, spray‐dried spheres, and denser shells. The heterogeneity and ideal fragmentation behavior was further assessed by calculating the replication factor of each support, indicating that silica materials containing macropores and spray‐dried shells have an almost ideal replication phenomenon. This multiscale analysis revealed new understanding of catalyst fragmentation for different supports. This understanding could in the future be further developed by the addition of more supports or additional analysis of the supports to the industrial database.

Rheological properties of phosphorus-containing oligoester(meth)acrylate for processing by vacuum infusion

Objectives. To obtain polymer composite materials (PCM) with enhanced physicomechanical properties using the vacuum assisted resin transfer molding (VaRTM) method, binders must have a viscosity of up to 500 mPa∙s. In some cases, this leads to restrictions on the use of certain materials or requires the use of temporary diluents. This is closely related to the deterioration of other required composite characteristics, such as increased flammability. Three phosphorus-containing oligoester(meth)acrylates PhOEM-1, PhOEM-2, and PhOEM-3 were synthesized with significant differences in viscosity characteristics in the series PhOEM-1 &lt;&lt; PhOEM-2 &lt;&lt; PhOEM-3. The polymer based on PhOEM-1 exhibits inferior physicomechanical properties despite having lower viscosity. Hence, the aim of the study was to investigate the viscosity characteristics of mixtures of methacrylate binders of the same nature but different structures and functionalities. This was done by studying the rheological properties of the original oligoester(meth)acrylates and their mixtures taken in various ratios. The method used was to optimize compositions via a simplex lattice (Scheffe’s plan), in order to obtain PCM using the VaRTM technology.Methods. The study of rheological properties of phosphorus-containing oligoester(meth)acrylates and their mixtures was conducted using the method of rotational viscometry on a Brookfield LVDV-II + Pro viscometer with a spindle 27 at different shear rates ranging from 0 to 70 s−1 and temperatures from 30 to 70°C. Rheological studies were also conducted on a Lamy Rheology GT300 PLUS (GEL TIMER) viscometer in the same range of shear rates and temperatures.Results. It was established that the objects under investigation can be characterized by viscosity values ranging from 96 to 2137 mPa∙s depending on the temperature. The nature of the viscous flow of phosphorus-containing oligoester(meth)acrylates and their mixtures is similar to that of Newtonian liquids only at certain shear rates. The effective activation energies of the viscous flow of binders and their mixtures were calculated, and the influence of temperature on the viscosity of binders was determined.Conclusions. The study identified the features and nature of the flow curves of phosphorus-containing oligoester(meth)acrylate binders of the same nature but different structures and functionalities, as well as of their mixtures. The optimal composition ranges of threecomponent mixtures of phosphorus-containing oligoester(meth)acrylates for use in the VaRTM technological process in producing polymer composite materials within the temperature range of 30 to 70°C were defined. The optimal compositions and temperature conditions for obtaining polymer composite materials using the VaRTM technology were also identified. This enables the production of polymer products with complex geometric shapes and varying sizes.

High-yield production of completely linear dextrans and isomalto-oligosaccharides by a truncated dextransucrase from Ligilactobacillus animalis TMW 1.971

Several lactic acid bacteria are capable of producing water-soluble exopolysaccharides such as dextran from sucrose by using glucansucrases. Several recombinant glucansucrases were described, however, yields are often limited and most dextrans are branched at position O3. In this study, the dextransucrase from Ligilactobacillus animalis TMW 1.971 was recombinantly produced without its N-terminal variable region and used for dextran synthesis. The enzyme expressed well and showed very high total as well as transferase activities compared to other glucansucrases. It was able to transfer nearly all glucose from sucrose to oligo- and polymeric products under certain conditions (about 95 % of glucose transferred). The high efficiency of the enzyme made it possible to obtain absolute dextran yields of up to 214.9 g/L from a 1.5 M sucrose solution. Structural characterization of the products showed that the dextrans produced have a rather low molecular weight, a narrow size distribution, and are completely linear. Furthermore, we showed that various low molecular weight dextrans or 1,6-linked isomalto-oligosaccharides can be efficiently produced by acid hydrolysis. Overall, we demonstrated that Ligilactobacillus animalis TMW 1.971 dextransucrase can be used to efficiently synthesize dextrans with a quite unique structural composition. The dextrans produced have a high potential for further applications such as synthesis of copolymers or size standards with a very defined molecular structure.

Enhanced MTBE removal in fixed-bed bioreactor with iron-modified carriers: Biofilm structure and microbial community

The residue of methyl tert-butyl butyl ether (MTBE) in groundwater poses a great threat to human health and needs to be addressed urgently. An efficient fixed-bed biofilm reactor was constructed by immobilizing MTBE-degrading bacteria Stenotrophomonas, Pseudoxanthomonas and Sphingobacterium on iron-modified activated carbon. The introduction of iron improved the specific surface area, zeta potential and hydrophilicity of the carrier, thus enhancing microbial adhesion. During reactor start-up, iron modification promoted the production of protein-dominated extracellular polymers, increased the biomass loaded on the carrier, and accelerated the formation of thicker (75.4 μm) and denser three-dimensional mesh biofilms. During operation, the iron-loaded reactor retained a thicker biofilm (157.9 μm) with greater stability and biological activity, which facilitated the removal of MTBE. Moreover, the iron-loaded biofilm system promoted the enriched growth of Stenotrophomonas with a higher percentage of MTBE-degrading bacteria (80%), increased species richness and diversity under adverse conditions, thereby enhancing metabolic capacity and environmental tolerance.

Two-way role of boron in microalgal-bacterial granular sludge: Enhanced signal communication for efficient metabolism

Based on the crucial role of boron in the metabolism of algae and bacteria, this study aimed to investigate the effects of boron on microalgae-bacterial granular sludge (MBGS) system. The addition of boron stimulated the secretion of autoinducer-2 to promote bacterial quorum sensing, which increased the extracellular polymeric substances production by more than 12.5 %. Meanwhile, boron significantly impacted the indole-3-acetic acid levels in microalgae to improve photosynthetic efficiency and increased the abundance of target algae (Chlorophyta and Cyanobacteria) by more than 0.23 times and 0.88 times, respectively. However, the influence of boron was not concentration-dependent, with the optimal concentration as 80 µM. Both boron deficiency and excess can heighten oxidative stress and affect the stability of the MBGS system. This study highlights the essentiality of boron in simultaneously influencing signal communication of algae and bacteria to strengthen synergy, and provides a theoretical basis for strengthening the symbiotic relationship within MBGS.