The application of diverse technological tools, encompassing Fourier transform infrared spectroscopy and X-ray diffraction patterns, allowed for a comparison of the structural and morphological characteristics of cassava starch (CST), powdered rock phosphate (PRP), cassava starch-based super-absorbent polymer (CST-SAP), and CST-PRP-SAP materials. read more Synthesized CST-PRP-SAP samples exhibited commendable water retention and phosphorus release capabilities. The reaction parameters, specifically 60°C reaction temperature, 20% w/w starch content, 10% w/w P2O5 content, 0.02% w/w crosslinking agent, 0.6% w/w initiator, 70% w/w neutralization degree, and 15% w/w acrylamide content, influenced these outcomes. CST-SAP samples with P2O5 content at 50% and 75% exhibited less water absorbency than CST-PRP-SAP, all ultimately displaying a gradual decline in absorption after undergoing three consecutive cycles. After 24 hours, the CST-PRP-SAP sample's water content remained at around 50% of its initial level, even when exposed to a 40°C temperature. An increase in PRP content and a decrease in neutralization degree corresponded to a rise in the cumulative phosphorus release amount and rate of the CST-PRP-SAP samples. After a 216-hour immersion, the cumulative phosphorus release and its release rate of the CST-PRP-SAP specimens with varying PRP compositions experienced a rise of 174% and 37 times, respectively. The beneficial effect on water absorption and phosphorus release was observed in the CST-PRP-SAP sample after swelling, attributable to its rough surface texture. In the CST-PRP-SAP system, the extent of PRP crystallization was reduced, and the majority of the PRP presented as a physical filler, ultimately resulting in a rise in the available phosphorus content. Analysis of the CST-PRP-SAP, synthesized within this study, revealed excellent capabilities for sustained water absorption and retention, complemented by functions facilitating phosphorus promotion and controlled release.

Investigations into how environmental conditions impact the characteristics of renewable materials, specifically natural fibers and their composite products, are becoming more prominent in research. The hydrophilic characteristic of natural fibers leads to their water absorption, which consequently impacts the overall mechanical properties of natural-fiber-reinforced composites (NFRCs). NFRCs are predominantly made from thermoplastic and thermosetting matrices, making them viable lightweight options for applications in automobiles and aircraft. For this reason, the endurance of these components to the most extreme temperatures and humidity is essential in disparate global regions. This paper, through a comprehensive review that incorporates current insights, examines the impact environmental conditions have on the effectiveness and performance of NFRCs, in accordance with the factors previously detailed. This study critically examines the damage mechanisms of NFRCs and their hybridized counterparts, with a specific focus on the influence of moisture ingress and varying humidity levels on their impact-related failure modes.

In this paper, the experimental and numerical analyses of eight restrained slabs, in-plane, with dimensions of 1425 mm (length) by 475 mm (width) by 150 mm (thickness), are presented; these slabs are reinforced with glass fiber-reinforced polymer (GFRP) bars. read more Inside a rig, the test slabs were placed, resulting in an in-plane stiffness of 855 kN/mm and rotational stiffness. The slabs' reinforcement varied in effective depth from 75 mm to 150 mm, and the amount of reinforcement altered from 0% to 12%, utilizing bars with diameters of 8 mm, 12 mm, and 16 mm. In evaluating the service and ultimate limit state behavior of the tested one-way spanning slabs, a different design approach is mandatory for GFRP-reinforced, in-plane restrained slabs that display compressive membrane action. read more Design codes rooted in yield line theory, while suitable for scenarios involving simply supported and rotationally restrained slabs, fall short in predicting the ultimate limit state behavior of GFRP-reinforced, restrained slabs. A significant, two-fold increase in failure load was measured for GFRP-reinforced slabs in tests, a finding consistent with the predictions of numerical models. In-plane restrained slab data from the literature, when analyzed, yielded consistent results that further validated the model's acceptability, with the numerical analysis supporting the experimental investigation.

The development of highly active late transition metal catalysts for isoprene polymerization, to enhance the properties of synthetic rubber, remains a considerable challenge. Employing elemental analysis and high-resolution mass spectrometry, a series of [N, N, X] tridentate iminopyridine iron chloride pre-catalysts (Fe 1-4) incorporating side arms were synthesized and verified. Iron compounds acted as highly effective pre-catalysts for isoprene polymerization, showing a significant enhancement (up to 62%) when combined with 500 equivalents of MAOs as co-catalysts, resulting in high-performance polyisoprenes. Through the combined application of single-factor and response surface optimization techniques, complex Fe2 demonstrated the highest activity, 40889 107 gmol(Fe)-1h-1, under the stipulated conditions of Al/Fe = 683; IP/Fe = 7095, and t = 0.52 min.

A key market demand in Material Extrusion (MEX) Additive Manufacturing (AM) revolves around the harmonious integration of process sustainability and mechanical strength. For the immensely popular polymer, Polylactic Acid (PLA), achieving these conflicting objectives simultaneously can be challenging, especially given the diverse processing parameters available with MEX 3D printing. Multi-objective optimization of material deployment, 3D printing flexural response, and energy consumption in MEX AM with PLA is the focus of this work. Using the Robust Design theory, an evaluation of the effects of the most significant generic and device-independent control parameters on these responses was conducted. Using Raster Deposition Angle (RDA), Layer Thickness (LT), Infill Density (ID), Nozzle Temperature (NT), Bed Temperature (BT), and Printing Speed (PS), a five-level orthogonal array was assembled. Twenty-five experimental runs, each comprising five specimen replicas, yielded a total of 135 experiments. The effect of each parameter on the responses was determined using analysis of variances and reduced quadratic regression models (RQRM). In terms of impact, the ID, RDA, and LT were ranked highest for printing time, material weight, flexural strength, and energy consumption, respectively. Significant technological merit is attributed to the experimentally validated RQRM predictive models, enabling proper process control parameter adjustment, particularly in the MEX 3D-printing context.

Polymer bearings employed on ships experienced hydrolysis failure at speeds below 50 rpm, subjected to 0.05 MPa pressure and 40°C water. The test's conditions were derived from the real ship's operational procedures. In order to conform to the bearing sizes of a real ship, the test equipment was subject to a complete rebuilding. A six-month water-soaking period eliminated the swelling. The polymer bearing's hydrolysis, highlighted in the results, was a consequence of the intensified heat generation and the decreased heat dissipation under the specific operating conditions of low speed, heavy pressure, and high water temperature. The wear depth in the hydrolysis region is exceptionally large, exceeding that of the typical wear area by a factor of ten, brought about by the melting, stripping, transferring, adhering, and accumulation of polymer fragments from hydrolysis, causing unusual wear. Extensive cracking was also noted in the polymer bearing's hydrolyzed region.

We explore the laser emission properties of a polymer-cholesteric liquid crystal superstructure with coexisting opposite chiralities, arising from the refilling of a right-handed polymeric scaffold with a left-handed cholesteric liquid crystalline material. Two photonic band gaps are observable in the superstructure's structure, each associated with either right- or left-hand circularly polarized light. In this single-layer structure, dual-wavelength lasing with orthogonal circular polarizations is achieved by incorporating an appropriate dye. The wavelength of the right-circularly polarized laser emission maintains a high degree of stability, in stark contrast to the thermally tunable wavelength of the left-circularly polarized emission. The design's ease of adjustment and basic structure suggest promising prospects for broad use in both photonics and display technology.

In this study, lignocellulosic pine needle fibers (PNFs), due to their significant fire threat to forests and their substantial cellulose content, are incorporated as a reinforcement for the styrene ethylene butylene styrene (SEBS) thermoplastic elastomer matrix, aiming to create environmentally friendly and cost-effective PNF/SEBS composites. A maleic anhydride-grafted SEBS compatibilizer is employed in the process. Through FTIR analysis, the chemical interactions in the composites under investigation confirm the presence of strong ester linkages between the reinforcing PNF, the compatibilizer, and the SEBS polymer. This establishes strong interfacial adhesion between the PNF and SEBS components. The composite's strong adhesion leads to superior mechanical properties, resulting in a 1150% enhancement in modulus and a 50% increase in strength compared to the matrix polymer. Furthermore, scanning electron microscopy (SEM) images of the tensile-fractured composite specimens corroborate the robust interface. Ultimately, the prepared composite materials exhibit superior dynamic mechanical properties, as evidenced by elevated storage and loss moduli and glass transition temperatures (Tg), compared to the base polymer, hinting at their suitability for engineering applications.

It is vital to establish a new method to prepare high-performance liquid silicone rubber-reinforcing filler. A novel hydrophobic reinforcing filler was crafted by applying a vinyl silazane coupling agent to the hydrophilic surface of silica (SiO2) particles. The modified SiO2 particles' structures and properties were substantiated by Fourier-transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), measurements of specific surface area and particle size distribution, and thermogravimetric analysis (TGA), with results suggesting a significant reduction in the aggregation of hydrophobic particles.