Advances in Polymer Technology最新文献

This review provides a comprehensive overview of the multifaceted factors influencing TPE foam production, with a specific focus on the intriguing role of induced crystallization. TPE foams excel in versatility and cost-effectiveness, yet their production faces several challenges, that significantly impact their final characteristics. The examination encompasses a range of factors, including solubility, diffusivity, interfacial tension, rheology, foaming parameters, nucleating agents, and the intricate influence of induced crystallization on TPE foam structure and performance. In TPE, crystallinity can be induced through various means including gas sorption, stress concentration, extrusion, annealing, and self-nucleation. These induced crystals serve as nucleation sites for heterogeneous nucleation during foaming. The advancements achieved in polymer foam are thoroughly evaluated in terms of both progress and limitations, drawing insights from various research findings. Furthermore, the review examines recent developments and explores the effects of induced crystallization on TPE foam.

Numerous studies have examined rattan and date palm fibers separately, but none have combined both fibers in a single composite. This research focuses on creating novel hybrid composites using untreated and treated rattan and date palm fibers. Fibers were treated with 3%, 4%, and 5% NaOH solutions. Fiber diameters were measured microscopically. The NaOH treatment enhanced the tensile strength of the fibers. Untreated rattan, midrib, and spadix stem fibers exhibited tensile strengths of 18, 57, and 37 MPa, respectively. Polyester was used as the matrix, combined with fibers in weight fractions of 70 : 30, 75 : 25, and 80 : 20. All composites were made for 1 : 1 rattan–midrib and 1 : 1 rattan–spadix stem fibers. Composites containing 20% treated rattan–midrib fibers displayed the highest tensile and flexural strengths, measuring 13 and 39 MPa, respectively. Meanwhile, rattan–spadix stem composites achieved the highest tensile strength of 14 MPa at 30% treated fiber loading, and the highest flexural strength of 28.91 MPa at 20% fiber wt.%. Additionally, SEM images of the tensile fracture surfaces revealed voids, cracks, and impurities. The goal was to develop a new composite that provides a low cost, structurally sound, and environmentally friendly strong material suited for industrial, construction, and aviation applications.

The article provides a brief overview of the use of zeolites as environmentally safe anticorrosion pigments for organic coatings on metals. The number of studies on zeolite-based inhibiting pigments has increased significantly in recent years, due to the need to replace chromates and reduce the content of phosphate corrosion inhibitors. Based on the results available in the literature, an assessment was conducted on the inhibitory properties of complex zeolite pigments obtained by various methods. Emphasis is placed on the advantages and disadvantages of ion exchange modification of zeolites with inhibitory substances and mechanochemical synthesis of pigments. Zeolites have a wide perspective in anticorrosion technologies due to their porous structure, large surface area, high pore volume, and the ability to accumulate inhibitory ions and molecules. Such properties of zeolites make possible their use for the development of self-healing or “smart” polymer coatings. Considering the environmental safety of zeolites and their excellent thermal and chemical stability, anti-corrosion polymer coatings inhibited by zeolite pigments could become an effective environmentally friendly alternative to chromate-based protective coatings. The main trends and prospects for the development of research in this domain are presented.

In this study, zinc ferrite nanoparticles (ZnFe₂O₄ NPs) were incorporated into a polycarbonate/polyethylene oxide (PC/PEO) blend using the casting method. The resulting blends were subjected to comprehensive analysis using various techniques. X-ray diffraction (XRD) analysis revealed that the presence of ZnFe₂O₄ nanoparticles had a significant impact on the crystal structure of the PC/PEO blend, leading to a reduction in crystallinity. Fourier-transform infrared (FT-IR) measurements further confirmed the uniform distribution and compatibility of PC and PEO as polymer components, as well as their compatibility with the blend containing ZnFe₂O₄ NPs. The optical properties of the PC/PEO blend, including band gap and Urbach energy, were quantified using the Kubelka–Munk method. The incorporation of ZnFe₂O₄ NPs resulted in the formation of sub-band states between the valence and conduction bands, leading to a decrease in the band gap values. Field emission scanning electron microscopy (FESEM) analysis revealed a noticeable modification in the surface roughness, with the addition of ZnFe₂O₄ NPs resulting in a smoother surface texture. The electrical properties of the blends, including dielectric constant, dielectric loss, and AC conductivity, were measured. The addition of ZnFe₂O₄ NPs increased the dielectric constant (ε′) at lower frequencies, while it remained relatively stable at higher frequencies due to the localized charge carriers within the polymer blend. The higher values of ε’ observed at lower frequencies can be attributed to the movement of ions, which contributes to enhanced ionic conductivity. The magnetic properties of the blends were evaluated, demonstrating an increase in magnetic saturation upon the addition of ZnFe₂O₄ NPs. These findings provide valuable insights into the structural, optical, electrical, and magnetic characteristics of PC/PEO blends incorporated with ZnFe₂O₄ nanoparticles, thereby highlighting their potential for a wide range of technological applications.

This study is based on the utilization of fish scale-derived collagen (FSC) as a potential filler material in polyurethane foam (PUF) composites. The composites were prepared with varying FSC concentrations (2.5%, 5 wt%, and 10 wt%) with the standard PUF matrix, while calcium carbonates in the standard sample (STD) were completely substituted with 50 wt% of collagen. When examining the effects of collagen concentration on mechanical characteristics, complex correlations emerge between tensile strength, elongation, tear resistance, and ductility. The results reveal that the addition of 2.5 wt% FSC increased tensile strength by 12.66% during heat aging, while the addition of 5 wt% at standard temperature increased elongation by 6.65%. Under normal conditions, collagen significantly enhanced the material’s resistance to tearing, demonstrating its potential for long-term durability. Under typical conditions, tear resistance showed notable gains, increasing by 84.85% (50 wt% FSC) and 33% (10 wt% FSC), respectively. The tear resistance, however, diminishes under heat aging for all concentrations. Morphological assessments indicate a consistent closed cell structure across all samples, with collagen potentially contributing to reinforcement. The study supports the sustainable use of fish scale-derived collagen as a filler, addressing waste management challenges and aligning with principles of environmentally conscious material development.

This study aimed to develop an innovative recycling method for end-of-life polycotton textiles, eliminating the need for component separation. The use of 1-ethyl-3-methylimidazolium acetate ([EMIM][Ac]) as an ionic liquid solvent facilitated the dissolution of cotton, enabling the creation of a spinning dope containing cellulose and polyester fibers. Successful spinning of bicomponent fibers ensued, followed by comprehensive fiber evaluation. The dissolution of cotton was achieved with [EMIM][Ac], and spinning trials were conducted to devise a suitable method for regenerated cellulose. Tensile tests on the produced cellulosic fibers clearly demonstrated an increase in tensile strength with higher cellulose concentration. The introduction of polyester fibers to the spinning dope, comprising [EMIM][Ac] and cotton, posed challenges to the entire spinning process. Tensile tests on the resulting bicomponent fibers revealed a decrease in tensile strength compared to pure regenerated cellulose fibers. This reduction was attributed to increased voids and irregular polyester fiber distribution, corroborated by microscopy images and a wicking test. It was concluded that the quantity and length of polyester fibers significantly influenced the tensile strength of the bicomponent fibers, with lower concentrations and shorter fibers resulting in higher strength.

The study investigates some 3D printing output parameters of a polycaprolactone (PCL) wood-based biopolymer, a category of materials obtained by embedding wood-derived components within polymeric matrices. These wood-based biopolymers have garnered significant focus in recent years due to their environmental friendliness and vast potential across many different fields. A full factorial design with three independent variables (layer height, printing speed, and heat treatment exposure time) at three levels was considered. The research explores printing speeds higher than the speed ranges typically investigated in the existing scientific literature on FDM 3D printing of wood-based polymers. Additionally, in this study, heat treatment is proposed as a post-processing operation to enhance certain crucial proprieties such as surface quality, hardness, mechanical strength, and accuracy. The findings reveal that heat treatment has a positive influence on the investigated output parameters. Notably, 3D printed samples subjected to heat treatment exhibit an average decrease of 112.1% in surface roughness for a 5-min exposure time and 121.73% for a 10-min exposure time. The surface hardness of the samples also improved after applying the heat treatment. The part hardness improved with an average of 0.65%. Furthermore, significant correlations were observed between layer height and surface quality, hardness, printing speed, and tensile strength. Notably, printing speed contributed significantly to the variation in tensile strength, accounting for 52.77% of the parameter’s variation. These insights shed light on the optimization of 3D printing processes for wood-based biopolymers, paving the way for enhanced performance and applicability across diverse fields.

A new hydrogenated nitrile butadiene rubber (HNBR) material filled with silane-modified nano-Al₂O₃ is developed in this work. Influence of the nano-Al₂O₃ and its contents on friction and wear performances of the HNBR materials is investigated. The nano-Al₂O₃ particles with different contents are added into the HNBR composites. Then, friction and wear tests are conducted using a pin-on-disk tribometer. Scanning electron microscope (SEM) is used to observe wear topography of the HNBR composite surfaces. Attenuated total reflection–Fourier transform infrared (ATR–FTIR) spectroscopy is used to investigate mechanism of nano-Al₂O₃ reinforcing HNBR. Results show that the filled nano-Al₂O₃ and its contents significantly affect friction and wear performances. Presence of the nano-Al₂O₃ obviously decreases friction coefficient and volume wear rate. Friction coefficient and volume wear rate of the composites reduce initially with the increase of nano-Al₂O₃ content and then increase with further increasing the nano-Al₂O₃ content. The HNBR material filled by the nano-Al₂O₃ with the content of 15 phr shows better antifriction and wear performances. SEM results indicate that the HNBR material filled by the nano-Al₂O₃ of 15 phr presents the best topography of wear surface compared with the HNBR materials filled by other nano-Al₂O₃ contents in this study. ATR–FTIR results show that mechanism of the nano-Al₂O₃ reinforcing HNBR for wear resistance is due to the graft reaction between the modified nano-Al₂O₃ and HNBR to form cross-linking networks around the Al₂O₃ nanoparticles, and self-polymerization of unsaturated groups on the surface of the nano-Al₂O₃ to form interpenetrating polymer networks with the HNBR molecular main chains.

With the continuous expansion of the global automobile fleet, there is an escalating demand to enhance and maintain current road infrastructure. Given the information provided, there will be a growing demand for bitumen, a key raw material used in the manufacturing of asphalt. Bitumen may account for up to 60% of the total usage in asphalt production. This study aims to determine the effect of different content of polylactic acid (PLA) on the change in the chemical and physical properties of biopolymer bitumen during its modification. This study was carried out by using a sample of petroleum road bitumen from CASPI BITUM (Kazakhstan) and a sample of PLA from Zhejiang Hisun (China). As a part of the research, the change of quality indicators of biopolymer bitumen when adding 4%–10% of PLA to it has been established. The results showed that the values of the average molecular weight and average molar mass increased with increasing the content of PLA in biopolymer bitumen. In particular, when the PLA content in biopolymer bitumen increased up to 10%, the average molecular weight of the biopolymer bitumen increased from 1,263 to 2,759 Mw and the average molar mass increased from 1,215 to 1,395 Mn. It was shown that increasing the PLA content in biopolymer bitumen from 0% to 10% leads to an increase in the softening temperature from 47 to 70°C or ∼ 49%. It was found that all examined samples of biopolymer bitumen are characterized by increased plasticity at 25°C (>100 cm). It has been established that the addition of 8% PLA to bitumen allows one to obtain a biopolymer bitumen of optimal quality. The results obtained can be used to produce road biopolymer bitumen.

The oil bitumen BND 90/130, produced at the “LLP SP Caspi Bitum” with the modifier, which consists of copolymer of ethylene with butyl acrylate and glycidyl methacrylate taken in an amount of 0.5–1.6 wt%, and the tire reclaim (4–20 wt%), which is the destructate of mesh elastomers of different chemical nature, was modified; possibility of using the developed bitumen-elastomer binders in road asphalt concrete was justified. Modification of bitumen with a copolymer of ethylene with butyl acrylate and glycidyl methacrylate leads to an improvement in the properties of road bitumen: the softening point, hardness, deformability at low temperatures, elasticity, and adhesion to metal and mineral filler increase. It was shown that ethylene with butyl acrylate and glycidyl methacrylate chemically interacts with the functional groups of bitumen asphaltenes through the epoxy group of glycidyl methacrylate. Analysis of the spectra and group composition indicates an increased content of high molecular weight asphaltenes in the modified bitumen with a slight increase in structuring resins. It has been established that bitumen modified with rubber crumbs of 0.6–1.0 mm in size has high elasticity. The most effective composition of a bitumen-regenerated composite material based on tire reclaim has been determined. In terms of the totality of physicochemical and operational characteristics and comparative cost, the most acceptable is the bitumen-regenerated composition (with a regenerate content of 20%) and is superior in the complex of properties to bitumen modified with an optimal content of ethylene with butyl acrylate and glycidyl methacrylate (1.6%). The technology for modifying bitumen with tire reclaim is less time-consuming, more economically profitable, and environmentally effective, since it utilizes large-tonnage waste of worn-out tires. The resulting bitumen-polymer compositions have a high positive set of properties: softening point, hardness, elasticity, frost resistance, and low-temperature characteristics.