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Bagasse ash (BA) is an agricultural waste obtained from power plants using sugarcane bagasse as an energy source. Although BA is successfully used as a building material, its application in the polymer industry remains challenging due to the lack of surface reactivity. In this study, BA was purified and named PBA before being incorporated into acrylonitrile butadiene rubber (NBR). Tannic acid (TA), a naturally occurring plant polyphenol, was used as a surface‐modifying agent for improved interfacial interaction. The effect of TA content on the properties of PBA‐filled NBR was investigated. The results showed that the presence of TA resulted in cure retardation, i.e., the scorch time, cure time, and activation energy of the vulcanization reaction increased with increasing TA content. However, the increase in TA content enhanced a rubber‐filler interaction, as evidenced by the considerable increase in bound rubber content. Such an enhancement resulted in the improvement of certain mechanical properties, including hardness, modulus, tensile strength, and tear strength. This research showed that tannic acid can be used as a surface‐modifying agent in NBR/PBA composites. [ABSTRACT FROM AUTHOR]

Highlights Starch‐based biocomposites exhibit great potential as an alternative to fossil‐based materials. This work focused on investigating the properties of the starch‐based biocomposite reinforced by cellulose nanofibers derived from sugarcane bagasse (SCB). The sodium hydroxide (NaOH) concentration was varied from 4%, 8%, and 12% wt/vol for the SCB extraction process. The obtained nanofibers, respectively called SCBNF4, SCBNF8, and SCBNF12, were characterized by various techniques prior to being incorporated into modified starch (MS). The effects of the type and amount of SCBNF on the mechanical properties, thermal behavior, optical transparency, and moisture absorption of the biocomposite films were examined. All SCBNF samples had a cellulose type I structure with a diameter on the nanometer scale, regardless of the NaOH concentration. The SCBNF's diameter decreased, whereas the crystallinity index increased with increasing NaOH concentration. When incorporated into MS, the higher SCBNF loading resulted in enhancements of mechanical properties and resistance to moisture absorption with the sacrifice of optical transparency. The biocomposite filled with SCBNF12 exhibited better overall performance at a certain filler loading due to the greater filler‐polymer interaction. The benefits of greater strength, light weight, and eco‐friendliness of the developed biocomposites make them suitable for many applications, including packaging. Diameter and crystallinity index of SCBNF were governed by NaOH concentration. Adding SCBNF to MS greatly improved the biocomposite's mechanical properties. SCBNF12 showed the highest biocomposite's overall performance. The maximum strength was achieved at 1 phr of SCBNFs. The addition of SCBNFs reduced water and moisture absorption. [ABSTRACT FROM AUTHOR]

This research explores the development of thermoplastic vulcanizate (TPV) blends derived from natural rubber (NR) and ethylene–butene copolymer (EBC) using a specific blend ratio and melt mixing technique. A comprehensive full factorial design of experiments (DOE) methodology is employed to optimize the processing parameters. TPVs are produced through dynamic vulcanization, combining rubber crosslinking and melt blending within a thermoplastic matrix under high temperatures and shear. The physico-mechanical properties of these TPVs are then analyzed. The objective is to enhance their mechanical performance by assessing the influence of blend ratio, mixing temperature, rotor speed, and mixing time on crucial properties, including tensile strength, elongation at break, compression set, tear strength, and hardness. Analysis of variance (ANOVA) identifies the optimal processing conditions that significantly improve material performance. Validation is achieved through atomic force microscopy (AFM), confirming the phase-separated structure and, thus, the success of dynamic vulcanization. Rubber process analyzer (RPA) and dynamic mechanical analyzer (DMA) assessments provide insights into the viscoelastic behavior and dynamic mechanical responses. Deconvolution analysis of temperature-dependent tan δ peaks reveals intricate microstructural interactions influencing the glass transition temperature (Tg). The optimized TPVs exhibit enhanced stiffness and effective energy dissipation capabilities across a wide temperature range, making them suitable for applications demanding thermal and mechanical load resistance. This study underscores the pivotal role of precise processing control in tailoring the properties of NR/EBC TPVs for specialized industrial uses. It highlights the indispensable contribution of the DOE methodology to TPV optimization, advancing material science and engineering, particularly for industries requiring robust and flexible materials. [ABSTRACT FROM AUTHOR]

Attempts to use bagasse ash (BA) as a filler in natural rubber (NR) have been made. Acidolysis/alkaline extraction method was used to purify BA. The purified BA (PBA) was subsequently characterized by various techniques such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and so forth. After the purification, PBA had a lower particle size and a higher specific surface area. XRD results showed that silica was the main composition of PBA while FTIR results revealed the existence of hydroxyl groups on the PBA surface. The reinforcement magnitude of PBA in NR was subsequently evaluated both without and with the addition of surface modifying agents, namely, bis-3-triethoxysilylpropyl tetrasulfide (TESPT) and epoxidized natural rubber (ENR). Due to its large particle size, PBA acted as a semi-reinforcing filler for NR, that is, the small increases of hardness, modulus and tensile strength were observed in the presence of PBA. As TESPT and ENR could improve the extent of rubber-filler interaction, mechanical properties of the NR vulcanizates filled with PBA-TESPT and PBA-ENR were slightly higher than those of the PBAfilled NR vulcanizate. For instance, tensile strength exhibited approximately 22% increase after the surface treatment. In this study, both PBA-TESPT and PBA-ENR showed comparable degree of reinforcement. KEYWORDS agricultural waste, bagasse ash, filled rubber, mechanical properties, natural rubber, surface modification, 1 | INTRODUCTION Nowadays, the applications of industrial waste in various industries have gained much attention from researchers around the globe due to the great concerns of environmental problems together [...]

This study involved the preparation of composites consisting of zinc oxide (ZnO) nanoparticles deposited within the structure of organophilic bentonite. These composites were subsequently utilized as fillers in natural rubber (NR). The organobentonites were initially prepared via a cation exchange reaction using alkylammonium ions with different chain lengths (C8N−C18N) and later deposited by ZnO nanoparticles. The identification of the ZnO‐organobentonites was conducted using various techniques, including powder X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), UV‐Vis spectroscopy, etc. The findings demonstrate the successful deposition of ZnO nanoparticles within the organobentonite's structure. The basal space between the silicate layers increased with the increasing chain length of alkylammonium ions. When added to NR, the ZnO‐organoclays mutually acted as a cure activator and filler. As expected, the ZnO‐organoclay modified by octadecylammonium ions (C18N) showed the greatest reinforcement due to its highest capability to enlarge the basal space between the silicate layers. [ABSTRACT FROM AUTHOR]

The influence of silane coupling agent on properties of silica-filled compounds under peroxide curing was investigated. bis (triethoxysilylpropyl) tetrasulfide (TESPT) was selected in this study and its content was varied from 0 to 12% w/w of silica. It is found that with increasing TESPT content, bound rubber content, tensile strength, elongation at break and tear strength are enhanced. By contrast, magnitude of Payne's effect, modulus at 100% elongation ([M.sub.100]) and heat build-up are decreased. The changes of such properties are attributed to the reduction of crosslink density in conjunction with the improvements of both rubber-filler interaction and degree of filler dispersion with increasing TESPT content in the peroxide curing system. POLYM. ENG. SCI., 59:42-48, 2019., INTRODUCTION Generally, the use of particulate reinforcing fillers in elastomeric materials is technically essential to achieve the required rubber properties including tensile strength, modulus, and abrasion resistance [1-3] while that [...]

Leucaena is a fast-growing tree in the legume family. Its leaf contains a significant amount of protein and is thus widely used as fodder for cattle. To broaden its application in the rubber field, the effects of Leucaena leaf powder and its extracted products on the cure characteristics and mechanical properties of natural rubber were investigated. The extraction of Leucaena leaf was carried out by using a proteolytic enzyme at 60 °C. The digested protein was separated from the residue by centrifugation. Both digested protein and residue were then dried and ground into powder, namely digested protein powder and residual powder, respectively, before being characterized by Fourier transform infrared spectroscopy, scanning electron microscope, thermogravimetric analysis, X-ray diffraction, particle size determination, and protein analysis. After being added to natural rubber at 3 parts per hundred rubber, they significantly reduced both the scorch time and the optimum cure time of the rubber compounds, probably due to the presence of nitrogen-containing substances, without a significant sacrifice of the mechanical properties. For instance, the optimum cure time decreased by approximately 25.5, 35.4, and 54.9% for Leucaena leaf powder, residual powder, and digested protein powder, respectively. Thus, they can be used as green and sustainable fillers with a cure-activation effect in rubber compounding. [ABSTRACT FROM AUTHOR]

With great concern of environmental threats, attempts have been made to reduce the consumption of zinc oxide (ZnO) in rubber products. This research aims at fabricating a new type of ZnO by depositing ZnO on microcrystalline cellulose (MCC) surface using an ultrasonic‐assisted hydrothermal process. The concentration ratio of Zn(NO3)2 to NaOH is varied from 1:1 to 1:4. The obtained products, namely MCC‐ZnO, are characterized by various techniques such as field emission scanning electron microscope, Fourier transform infrared spectroscopy, X‐ray diffraction, Brunauer–Emmett–Teller, and Thermogravimetric analysis. Results show that the amount of deposited ZnO and the specific surface area of MCC‐ZnO increase continuously with increasing NaOH concentration. The MCC‐ZnO (1:3) containing approximately 55.6 wt% of deposited ZnO is selected for investigating the curing efficiency in natural rubber (NR) and compared with the commercial ZnO (C‐ZnO). Obviously, the state of cure progressively increases with increasing either MCC‐ZnO or C‐ZnO content. At the same content, MCC‐ZnO exhibits a significantly higher crosslink density than C‐ZnO leading to the superior elasticity and mechanical properties. This could be explained by the greater specific surface area and, thus, the higher reactivity of MCC‐ZnO. Clearly, a considerably lower quantity of MCC‐ZnO is required to attain a similar level of crosslink density or mechanical properties as compared to C‐ZnO. [ABSTRACT FROM AUTHOR]

Generally, fly ashes (FA) could function as either semi-reinforcing or non-reinforcing fillers in polymeric systems, depending on particle size, specific surface areas and surface chemistry of FA particles. Typically, FA particles are spherical with smooth surfaces having significant influences on viscoelastic and mechanical properties. Additionally, the presence of heavy metals in FA particles could play role on degradation process of rubber molecules to some extent. In this article, the storage instability and thermal aging properties of FA filled natural rubber (NR) compounds were focused via changes in viscoelastic responses. Results obtained reveal that the storage duration of FA filled NR compounds leads to decreases in elastic modulus and molecular weight, particularly in the compounds with high FA loading. By replacing NR with polyisoprene (IR) containing no non-rubber substances, the storage stability is significantly enhanced. It is believed that the presence of metal ions in both FA and non-rubber substances in NR could catalyze the degradation process of rubber molecules. Such degradation process could effectively be suppressed by the addition of amine-based antioxidant.