Natural rubber latex (NRL) is a biopolymer consisting of isoprene monomers in a cis configuration connected by double bonds that can degrade naturally. Most natural rubber (NR) based products are single-use items and its microbial degradation process is relatively slow. Hence, this review highlights the importance in the enhancement of biodegradation of NR, the methods applied to increase the biodegradation rate, and characterization of biodegradation of rubber. The biodegradability of NR-based products is enhanced via selective microorganism strains, suitable composting environment and the addition of biofillers. Rubber oxygenase enzymes and latex cleavage protein are major contributors in the biodegradation of NR-based products, while biofillers such as chitosan, cellulose whiskers and starch enhances biodegradation rate up to 60 %. Biodegradation of NR-based products is confirmed through characterization of physicochemical, thermal and mechanical properties using SEM, XRD, FTIR, GPC, TGA, UTM, physical appearance and weight loss. NR-based materials with enhanced biodegradability have many uses, thus its customizability should be studied further in terms of different product forms, fabrication method, orientation of biofiller used and incorporation of metal organic frameworks.

Rubber-based intercropping is a recommended practice due to its ecological and economic benefits. Understanding the implications of ecophysiological changes in intercropping farms on the production and technological properties of Hevea rubber is still necessary. This study investigated the effects of seasonal changes in the leaf area index (LAI) and soil moisture content (SMC) of rubber-based intercropping farms (RBIFs) on the latex biochemical composition, yield, and technological properties of Hevea rubber. Three RBIFs: rubber-bamboo (RB); rubber-melinjo (RM); rubber-coffee (RC), and one rubber monocropping farm (RR) were selected in a village in southern Thailand. Data were collected from September to December 2020 (S1), January to April 2021 (S2), and May to August 2021 (S3). Over the study period, RB, RM, and RC exhibited significantly high LAI values of 1.2, 1.05, and 0.99, respectively, whereas RR had a low LAI of 0.79. The increasing SMC with soil depths was pronounced in all RBIFs. RB and RM expressed less physiological stress and delivered latex yield, which was on average 40% higher than that of RR. With higher molecular weight distributions, their rheological properties were comparable to those of RR. However, the latex Mg content of RB and RM significantly increased to 660 and 742 mg/kg, respectively, in S2. Their dry rubbers had an ash content of more than 0.6% in S3.

The current study discusses the preparation and characterization of green composite from coarse wool fabric and natural rubber (NR) latex. Natural rubber latex was coated on the coarse wool fabric by the hand lay-up method and vulcanized to form a flexible composite sheet. Standard techniques were used to determine the physicomechanical parameters, including areal density, thickness, solvent diffusion, and abrasion resistance. Scanning electron microscopy was used to analyze the morphology of the fracture surfaces. The composite sample was further analyzed using Fourier transform infrared spectroscopy to determine changes in the chemical structure. The viscoelastic properties of the composite were investigated using a dynamic mechanical analyzer. The aging of the composite with respect to accelerated temperature, UV radiation, and soil burial was also investigated through standard methods. The developed coarse wool-rubber latex composite was found quite flexible, unlike conventional stiff fiber-reinforced composites. The scanning electron microscopy images depicted that rubber latex infiltrated the wool fabric matrix. The solvent diffusion studies showed slow penetration of water and toluene inside the composite due to a dense network of natural rubber inside the wool fabric. During the soil burial test, the composite lost 13% of its weight. A clutch bag and a shoulder bag were developed using the prepared composite. The newly developed coarse wool-NR latex composite has potential uses in technical textiles, conveyor belts, and fashion accessories.Highlights Natural rubber (NR) latex was coated on the coarse wool fabric and vulcanized. The wool-NR latex composite showed excellent physico-mechanical properties. The thermal and UV aging properties were also found to be good. The developed composite is flexible, derived purely from natural sources, and inexpensive. The wool-NR latex composite could find potential applications in fashion accessories.

Heavy metal pollution and soil salinization harm human health and the environment. Phytoremediation is a widely accepted soil decontamination method, with woody plants being particularly effective due to their large biomass and extensive root systems. In this study, we identified and cloned PsnMLP328 from Populus simonii x P. nigra and demonstrated its role in mitigating salt and cadmium stress. PsnMLP328 expression was up-regulated under both stress conditions, and its overexpression in tobacco enhanced resistance to these stresses, albeit through distinct mechanisms. Transgenic plants exhibited increased Cd2+ uptake and a higher biomass, alleviating Cd2+-induced growth inhibition. Additionally, PsnMLP328 boosted proline content, chlorophyll levels, and antioxidative enzyme activities (POD, SOD) under Cd2+ stress, likely by protecting cells from oxidative damage. Expression analysis revealed that PsnMLP328 down-regulated the cadmium transporter Nramp2 while up-regulating YSL2 (another cadmium transporter) and potassium channels (AKT1 and AKT2/3), suggesting its role in modulating K+ and Cd2+ homeostasis. These findings indicate that PsnMLP328 enhances tobacco resistance to salt and cadmium stress, particularly the latter. This study is the first to elucidate the function of poplar MLP family genes under salt and cadmium stress, advancing our understanding of MLP gene roles in heavy metal stress and offering new insights for remediating salinized and heavy metal-contaminated soils.

This study investigates the use of IoT-enabled environmental monitoring to compare the effects of natural rubber latex (NRL) and traditional mulching materials, including rice straw and polyethylene (PE) film, on the growth, yield, and postharvest quality of Cucumis sativus L. (cucumber). The research specifically explores NRL-based film and straw as sustainable mulching alternatives, enhanced with cellulose nanocrystals (CNC) for improved mechanical properties. Environmental conditions, including soil temperature, moisture, and air conditions were continuously monitored using IoT sensors, providing real-time data for analysis. The results show that NRL straw significantly reduced soil temperature by 1-4 degrees C, promoting better cucumber growth and higher yields than either rice straw or PE film. NRL film increased soil moisture retention at a 5 cm depth and improved fruit quality, particularly in terms of skin color. Both NRL mulching types demonstrated strong potential for sustainable agriculture by enhancing growth efficiency, reducing environmental impact, and offering a costeffective alternative to synthetic mulching materials. These findings underscore the value of IoT technology in optimizing resource use and improving crop management in modern agricultural systems.

A few recent studies introduced natural rubber latex (NRL) as a stabilizer for improving the mechanical properties of soil such as ductility, compressive and tensile strengths, durability, etc. However, none of these studies addressed the effect of NRL treatment on swelling and compressibility of soil. The present study investigates the effect of NRL treatment on swelling and compressibility characteristics of three soils of different plasticities by conducting oedometer tests. Untreated and NRL-treated samples of the selected soils were prepared with the same soil dry density. For preparing treated samples, in place of water, NRL was added to soil. The results of one-dimensional swelling-compression tests demonstrated that in low and medium plastic soils, NRL treatment increased the swelling potential marginally, whereas it considerably reduced the swelling in the high plastic soil, which is expansive in nature. NRL did not cause any changes in the swelling pressure of medium plastic soil. At the same time, it brought about a considerable drop in the swelling pressure of high plastic soil. In the consolidation tests, a decrease in compressibility, quantified in terms of compression index, was observed in all soils after NRL treatment. The resilient nature of rubber content caused an increase in the recompression index in all treated samples. A reduction in the coefficient of consolidation was observed in NRL-treated soils. The study concludes that despite the high deformability of rubber, NRL treatment does not negatively affect the swell-compression behaviour of soils. Besides, the treatment effectively controls the swelling and compression of highly compressible soil.

This study explores the efficacy of Natural Rubber Latex (NRL) as an additive in enhancing the mechanical properties and durability of cement-stabilized Recycled Concrete Aggregate (RCA) and Lateritic Soil (LS) blends for pavement applications. The research focused on determining the optimal NRL content and evaluating the performance of the stabilized blends under environmental stress represented by wetting-drying (w-d) cycles. Unconfined Compressive Strength (UCS) and Indirect Tensile Strength (ITS) tests were conducted alongside Scanning Electron Microscopy (SEM) to assess the microstructural integrity of the materials. The results demonstrated that the inclusion of NRL at a 5% rubber-to-cement (r/c) ratio significantly improved the initial UCS, ITS, fatigue life, and durability performance of the RCA:LS blends. The 70:30 RCA:LS blend outperformed the 50:50 blend, indicating a composition-dependent response to NRL addition. The findings suggest NRL's potential in sustainable pavement construction, with implications for enhancing strength in stabilized pavement materials.

This study evaluates styrene butadiene rubber (SBR) and styrene acrylic latex (SA) as modifiers in cement-treated subbase materials (CTSB) to enhance mechanical properties and reduce cement usage sustainably. Optimal ratios for stabilizing sub-standard lateritic soils were identified, reducing water demand and increasing mechanical strength in polymer-modified cement pastes. A 10 % SA and a 15 % SBR as cement replacement by mass significantly improved bearing strength and strain capacities in CTSB, signifying enhanced flexibility and elasticity. Despite slight changes in compaction characteristics, the study identified 1.6 % SA and 2.4 % SBR as optimal binder (i.e., polymer-cement mixture) contents, compared to 3.3 % cement for conventional CTSB with similar unconfined compressive strength standards. SBR-enriched CTSB exhibited superior resilient modulus, indicating stronger inter-particle bonding. The integration of SA and SBR reduced capillary rise and enhanced moisture stability. This sustainable approach enhances pavement durability and reduces CO2 emissions by minimizing cement use. The findings emphasize the potential of polymer-modified CTSB for cost-effective and environmentally friendly road construction, offering significant implications for advancing pavement engineering materials and promoting eco-friendly practices within the industry.

Green natural rubber (NR) composites reinforced with synthetic graphite platelets, using alginate as a thickening and dispersing agent, were successfully developed to improve mechanical properties, chemical resistance, and electrical conductivity. The fabrication was performed using a latex aqueous microdispersion process. The research demonstrated the effective incorporation of graphite platelets into the NR matrix up to 60 parts per hundred rubbers (phr) without causing agglomeration or phase separation. Graphite incorporation significantly improved the mechanical strength of the composite films. NR with 60 phr of graphite exhibited the highest Young's modulus of 12.3 MPa, roughly 100 times that of the neat NR film. The reinforcement also strongly improved the hydrophilicity of the composite films, resulting in a higher initial water absorption rate compared to the neat NR film. Moreover, the incorporation of graphite significantly improved the chemical resistance of the composite films against nonpolar solvents, such as toluene. The composite films exhibited biodegradability at about 21% to 30% after 90 days in soil. The electrical conductivity of the composite films was considerably enhanced up to 2.18 x 10-4 S/cm at a graphite loading of 60 phr. According to the improved properties, the developed composites have potential applications in electronic substrates.