Journal of Polymer Research最新文献

In this paper, a string of waterborne polyurethane (WPU) emulsions synergistically modified with PDMS and GMS were successfully prepared by incorporating Polydimethylsiloxane (PDMS) into the soft segments of waterborne polyurethanes, and using glycerol monostearate (GMS) as a chain extender. FTIR, TGA, SEM, particle size test, water contact angle and other tests were used to characterize the effects of variable GMS contents on the structure and function of WPUs. The experimental tests showed that the WPUs synthesised with 30% PDMS-8% GMS synergism had better overall performance. The water contact angle could reach 115.4°, and the water absorption was reduced to 10.52% at 72 h. Furthermore, this innovative WPU film had excellent thermal stabilization, and this study provided a new approach to improve waterproofing performance, hydrophobicity and thermal stability of waterborne polyurethanes, which is expected to be applied in coatings, adhesives and water-resistant agents.

In this work, a composite polymer electrolyte based on poly (ethylene glycol)/poly(acrylonitrile) (PEG/PAN) has been fabricated using the electrospinning technique, with varying weight ratios of gadolinium oxides (Gd₂O₃). Employing polymeric electrolytes having comparatively high mechanical strength, improved safety, and exceptional flexibility as alternatives to traditional electrolytic fluid is an efficient technique for reducing lithium (Li) dendrite development in Li-based batteries. Nevertheless, inadequate ionic conductivity, insufficient thermal resistance, and an extremely tiny electrochemical window continue to limit their uses. We present Gd₂O₃ nanofibers enabled PAN/PEG-based composite polymer electrolytes (CPEs) with improved ionic conductivity and large electrochemical windows. The investigation found that adding 15 Wt.% Gd₂O₃ nanofiber to PAN/PEG results in a flexible electrolyte membrane with increased performance, including high ionic conductivity (1.026 × 10^–4 S cm⁻¹) at RT, Li⁺ transfer number is 0.83, a broad electrochemical window (5.5 V), and good thermal shrinkage 150 °C, electrolyte uptake upto (~ 246%), porosity upto (~ 97%), and activation energy (0.23). This study demonstrates that adding Gd₂O₃nanofibers could enhance the electrochemical efficiency of PAN/PEG based This study demonstrates adding Gd₂O₃nanofibers could enhance the electrochemical efficiency of PAN/PEG-based composite polymer electrolytes for energy storage applications.

Ring-opening addition reactions between pentaerythritol tetra(oxiran-2-ylmethyl) ether [pentaerythritol polyglycidyl ether (PPE)] and polyethylenepolyamine, i.e., ethylenediamine (EDA), diethylenetriamine (DETA), triethylenetetramine (TETA), and tetraethylenepantamine (TEPA), have been investigated to yield network polymers. The reactions in ethanol under the equivalent molar ratio of epoxy and NH groups, [epoxy]/[NH] = 1.0 mol/mol, at 60 ºC successfully yielded porous polymers. The surface morphology of the porous polymers showed connected particles with the diameters ranged from bout 5 μm to 20 μm. The monomer concentration and molecular structure of the polyethylenepolyamine compound affected the particle size in the porous polymers. All the porous polymers were sufficiently soft and flexible to be unbroken under 40 N of compression. The porous polymers absorbed various solvents and showed high water permeability. The porous polymers adsorbed an anionic dye selectively. Surface treatment of a porous polymer by alkali aq. made it possible to adsorb a cationic dye.

Fusion deposition modeling (FDM) has developed remarkably over the last few decades as an innovative and versatile method of producing objects with complex design details. Polylactic acid (PLA), a bio-based polymer, is one of the most widely used thermoplastics in fabricating products with FDM due to its favorable mechanical properties, relatively low cost, and recyclability. However, most PLA studies in the literature have focused on evaluating its mechanical performance according to the 3D-printed parts to changing FDM parameters. This experimental study tries to elucidate high-speed mechanical performance of PLA samples at different waiting times depending on varying media such as dry, seawater, and distilled water. It aims to form a scientific bridge between the liquid absorption and high-speed deformation behavior of 3D-printed PLA. In addition, samples with three different layer heights were produced to investigate the combined effect of these media and process parameters on FDM parameters. Low-speed tensile tests, hardness tests, drop-weight impact tests, and damage inspections were carried out to analyze the samples thoroughly. These results indicated that there was an affirmative relation between the hardness values and layer height levels. The maximum drop weight force value was obtained in dry samples with 0.2 mm layer height. In addition, the maximum force was higher for samples stored in seawater than for other samples. The specific absorbed energy (SAE) value of the samples at 0.2 mm layer height after 15 days of waiting time was superior to that of the dry sample.

Herein, this study introduces a simple, effective, and potentially successful approach to the preparation of polymeric composite systems using a Polyvinyl alcohol (PVA)-Polyvinyl pyrrolidone (PVP)-Polyethylene glycol (PEG) (PVA-PVP-PEG), (8:1:1) as the host polymeric blend with the inclusion of Tb(NO₃)₃-salt filler. The diffraction of X-rays (XRD), infrared spectroscopic (FTIR), Ultraviolet–visible (UV–vis) spectroscopy, and Phy-X/PSD software were utilized to analyze the modified samples’ structures, identify their optical and radiation shielding properties. The XRD patterns show the presence of Tb(NO₃)₃ phases inside the composite matrix, where adding filler causes modifications in the polymeric network’s structure for filled composite samples. FTIR analysis showed that the Tb(NO₃)₃-salt interacted with the blend’s functional groups via H-bond formation. The UV–Vis spectra analysis showed all samples, especially those loaded with 8.0 wt.% Tb(NO₃)₃-salt has the highest values for absorbance, dielectric constant, refractive index, extinction coefficient, and optical and electrical conductivity. Tauc’s formula, the ASF model, and " ({varepsilon }_{i}-hv) plots were all applied to investigate optically the band gap in great detail. The values of ({text{E}}_{text{d}}) and ({text{E}}_{text{o}}) and ({text{n}}_{text{o}}) have been investigated using a single oscillator model where their values were controlled by Tb(NO₃)₃- salt content. Using calculated gap energy, various approaches were applied to obtain the conceptual significance of the linear refractive index ((n)). The nonlinear optical parameters ({upchi }^{(1)}), ({upchi }^{(3)}), and ({text{n}}_{2}) increased noticeably as the Tb(NO₃)₃-salt percentage is increased to 8.0 wt%. The suggested largely doped Tb(NO₃)₃-salt composites show great promise as a CUT-OFF laser filters and attenuators in addition to being used in laser power-limiting technology. Based on our results, the sample was 8.0 wt.% Tb(NO₃)₃-salt has better gamma-ray shielding properties than the others because it has the largest Tb(NO3)3-salt concentration. The study opens a new route to fabricate Tb(NO₃)₃/(PVA-PVP-PEG) polymeric composites with superior optical properties.

The current challenge with sulfonated aromatic polymer proton exchange membranes (PEMs) lies in their inability to enhance proton conductivity, mechanical strength and methanol resistance concurrently. To address this issue, a novel approach has been taken by synthesizing hydrophobic polysulfone grafted with hydrophilic sulfonated polyvinyl alcohol (PSU-g-SPVA) through Reversible Addition-Fragmentation Chain Transfer (RAFT) polymerization. This graft polymer is then utilized as a modified material for PEMs in direct methanol fuel cells (DMFCs). The morphology of phase separation within the Nafion matrix is significantly influenced by the proportion of PSU-g-SPVA. Notably, the Nafion/PSU-g-SPVA-40 modified demonstrates superior alcohol resistance, with a methanol permeability rate of 2.32 × 10⁻⁷ cm²/s. Furthermore, due to its outstanding proton conductivity, the proton selectivity of this modified membrane is an impressive 10.9 × 10⁴ S s/cm³, which significantly surpasses that of the standard Nafion membrane at 2.82 × 10⁴ S s/cm³. Grafting techniques of hydrophobic main chain and hydrophilic side chains open up a new method for the blending of polymers with huge polarity differences.

A series of novel network polymers P₁-P₆ and P_n-Zn_x:y based on metal–ligand coordination bonds with different strength were prepared by one pot method. The structures of the polymers were confirmed by NMR and FT-IR spectra. The amorphous structure of polymers was determined by X-ray diffraction analysis with only broad scattering peaks detected. The TGA and DSC showed that the increase of pyridyl group can dramatically improve the thermal stability of polymers, and T_g gradually decreases with the increase of pyridyl and pyridine groups. When the amount of Zn(II) increases, the thermal stability and the T_g gradually decreases. Optical microscope images indicated that the cross-linked network polymers P_n-Zn_1:2 all had obvious self-healing properties at room temperature, and the 50% cross-linked network P₃-Zn_1:2 and P₄-Zn_1:2 with less pyridine content have better self-healing performance. Further exploration of the self-healing properties of P₃-Zn_x:y by adjusting the molar ratio of dianhydride to Zn(II), P₃-Zn_1:4 has the best self-healing performance.

New natural cellulosic materials used to make high-performance bio-based composites are attracting a lot of attention due to their enhanced properties. This study aimed to investigate micro-sized cellulosic fillers produced from Mangifera indica (Mango) leaves (MIL) with respect to their morphological and physicochemical properties, thermal behaviour, crystallinity and other relevant parameters. Some of cellulose's notable properties are excellent mechanical capabilities, biocompatibility, low density, biodegradability and heat stability. An acid hydrolysis process was used to extract cellulose from dried MIL. Isolated microcrystalline cellulose's crystallinity index and crystalline size were measured using X-ray diffraction, with results of 58.6% and 20.28 nm, respectively. The extracted cellulose filler's morphology was investigated using FESEM and ImageJ. The FESEM image shows MCCs morphology, thick framework formation, cellular structure, microfibrils, surface roughness and bonding making it a promising candidate for high-strength applications due to its enhanced bonding surface and structural integrity. The average size of the microfillers was found to be 103.161 μm. The absence of lignin, hemicelluloses and other non-cellulosic impurities in the extracted cellulose fillers was verified by infrared analysis employing Fourier transforms (FTIR). The findings suggest that waste materials that are already present in nature can be transformed into useful components for polymeric composites that can withstand processing temperatures ranging from 180℃ to 200℃. Surface roughness indicates cellulose is smooth, appropriate and noticeable without cracks. Therefore, lot of possibilities for extrusion methods in incorporating these microparticles into polymer composites.

With the rapid economic development in recent years, there has been an increasing demand for durable and high-performance transportation road pavements. Polymer-modified asphalt has gained widespread acceptance due to its ability to enhance driving comfort and extend service life. Nevertheless, the longevity of asphalt pavements is often compromised by long-term traffic loads and harsh weather conditions, leading to cracking and degradation. To tackle this issue, dynamic chemistry introduces a promising solution for self-healing polymer-modified asphalt. By integrating dynamic bonds into the polymers structure, its network becomes adaptable to external triggers such as pressure, temperature, and pH, enabling material self-repair via dynamic healing mechanisms. This paper explores the synthesis methods and structural characteristics of dynamic self-healing polymers, their impact on the self-healing performance of modified asphalt and the classification of dynamic bonds. Additionally, the paper discusses methods for evaluating the self-healing performance and identifies future challenges and research directions for self-healing polymer-modified asphalt materials.

Building lighter but stronger has been a major industrial concern in recent decades. To achieve its goals, Altuglas International, a subsidiary of the Arkema group, has developed several types of nanostructured acrylic glass materials, that are lighter and more resistant than glass PMMA. Combining PMMA (polymethyl methacrylate) and a nanostructured elastomer, this material has perfect transparency and special mechanical properties. In addition to its automotive applications, its exceptional properties open up prospects in aeronautics and safety glazing. In the present study, different type of nanostructured PMMA, with different crosslink density has been studied and compared to standard PMMA, shock PMMA and polycarbonate (PC). Various mechanical tests, including, scratch-based friction tests (to assess the fracture and friction properties), indentation tests (to obtain elasto-plastic behavior and the creep response), fracture toughness assessment tests and dynamic mechanical analyses, have been performed. Furthermore, perforation tests, were carried out using pneumatic gas gun having different impact velocities varying from 8 to 161 m/s. The obtained results show the combined effect of both rubber bloc nanostructuration and crosslink density. It’s was observed that the addition of rubber at nanometer scale leads to improvement of mechanical properties such as toughness, friction and impact resistance. Moreover, when moderately increasing the crosslink density, several physical properties, including glass transition temperature, toughness, friction, hardness and ballistic limit were significantly improved.