Search

With the rapid advancement of the flexible electronics industry, there is an urgent need to enhance the mechanical properties and thermal stability of flexible electronic devices to expand their range of applications. To address this need, flexible conductive composites have been developed using waterborne polyurethane (WPU) as the matrix, carbon nanotubes (CNTs) and graphene (GA) as conductive fillers, and incorporating cellulose nanofibers (CNFs). The carbon fillers create a conductive and thermal conductivity network within the matrix, while the presence of CNFs improves the dispersion of CNTs and GA, thereby enhancing the overall network structure. The resulting WGNF composites exhibit a resistivity of up to 1.05 × 104 Ω·cm, a tensile strength of 26.74 MPa, and a thermal conductivity of 0.494 W/(m·K). This demonstrates that incorporating cellulose offers an effective solution for producing high-performance polymeric conductive and thermally conductive composites, showing promising potential for flexible wearable devices. [ABSTRACT FROM AUTHOR]

Amid environmental pollution and resource depletion, developing and utilizing biomass resources as alternatives to petroleum is a prominent research focus. Driven by environmental protection and sustainable development, the shift from petroleum-based to bio-based polyurethane is a prevailing trend in polyurethane material development. Biomass sources such as vegetable oil, polysaccharides, and lignin offer extensive application prospects in bio-based polyurethane production. Functional modifications of these polyurethanes can further expand their application range. This article explores the preparation of various bio-based polyurethanes, their applications across different fields, and their anticipated future development and uses. [ABSTRACT FROM AUTHOR]

The adhesion strength and water resistance of stainless steel and adhesive resin composites determine the long-term performance of wires and cables; however, adhesion at stainless steel interfaces is difficult. Herein, we prepared ethylene acrylic acid/linear low-density polyethylene (EAA/LLDPE) blends with good mechanical and adhesive properties. Silane was anchored to the surface of stainless steel. The effects of silane functionalization on the adhesion surface were investigated by X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. The reaction mechanism between the stainless steel, silane, and EAA/LLDPE revealed adhesion was optimized when a 3:7 volume ratio of 3-methacryloxypropyltrimethoxysilane (MEMO): 3-aminopropyltrimethoxysilane (A-1110) was used to modify the stainless steel substrate. SEM images of EAA/LLDPE film peel surfaces found the silane-treated stainless steel substrates produced rough surfaces with a uniform void indicating the silane treatment enhanced the stainless steel and EAA/LLDPE film interaction. The stainless steel and EAA/LLDPE film adhesion and water resistance improved and the peel strength after water resistance testing at 68 C for 168 h increased from 3.18 N/cm to 9.37 N/cm compared to untreated stainless steel. Silane-modified stainless steel and EAA/LLDPE blend film composite materials demonstrate potential for application in wires and cables used in environmental corrosion-resistant applications., INTRODUCTION Metal-plastic composite tape is an indispensable component of communication cables. The water and corrosion resistance of aluminum-plastic or steel-plastic composite tape plays an important role in the service life [...]

To achieve the maximal improvement in the crystallization rate and heat resistance of poly(ethylene terephthalate) (PET), 2.6 mol% of ZnCl2 ionized polyamide (PA)‐66 (PA‐66–Zn), with a strong coordination ability, is prepared and used as PET nucleator. This study found that the PA‐66–Zn heterogeneously nucleates PET more effectively than the CaCl2‐ionized PA‐66 and non‐ionized PA‐66 by differential scanning calorimetry, crystallization kinetics, X‐ray diffraction, and polarized optical microscopy. This is probably a result of the introduction of stronger ion–dipole interactions (IDIs) between the PET esters and the ionized‐PA‐66 ZnCl2‐coordinating amides, which obviously heightens the PET/PA‐66–Zn interfacial compatibility. As shown by scanning electron microscopy, the compatibilization through an appropriate concentration of IDIs promotes the formation of smaller and denser PA‐66 crystals with immensely increased nucleator efficiency. Furthermore, the PET/PA‐66–Zn with significantly improved crystallinity displays a remarkable increase in heat‐resistant temperature, at 21.6 and 55.1°C higher than that of PET/PA‐66 and PET, respectively. The results demonstrate that the PA‐66–Zn can act as a superior nucleator and as an outstanding heat‐resistant agent for PET. [ABSTRACT FROM AUTHOR]

Zn‐salt poly(styrene–ran–cinnamic acid) (SCA–Zn) ionomers were successfully synthesized via the melt neutralization of poly(styrene–ran–cinnamic acid) (SCA), which has a comparable molecular weight (M¯w = 217,000) to commercial polystyrene (PS), with different mass fractions of ZnO (0.62, 1.6, and 3.9 wt.%) and the successful synthesis was confirmed by Fourier transform infrared spectroscopy. The mechanical properties, heat resistance, and processibility of the PS, SCA, and SCA–Zn samples were characterized. Compared to SCA, the three SCA–Zn ionomers exhibited significantly higher αcN values, with the ionomers containing 1.6 and 3.9 wt.% ZnO were 11.4% and 68.6% higher than that of SCA, respectively. Compared to commercial PS, SCA–Zn also exhibited significant improvements in heat resistance (glass transition temperature and vicat softening temperature both improved by about 20 °C) and impact toughness (αcN values of the ionomers containing 1.6 and 3.9 wt.% ZnO were 69.6% and 156.5% higher than that of PS), while the processability of SCA–Zn was not significantly worse than that of PS. This method efficiently improves both the toughness and heat resistance of PS, providing an efficient way to expand the market application of styrenic resins. [ABSTRACT FROM AUTHOR]

Copyright of Zeitschrift für Kristallographie / New Crystal Structures is the property of De Gruyter and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A poly(methyl methacrylate)-supported Pd 0 nanocatalyst was successfully prepared from solution reaction of Pd(CH 3 COO) 2 with a copolymer acid, poly(methyl methacrylate- ran -methacrylic acid) (MMA-MAA). The reaction was carried out in a benzene/methanol mixed solvent in the dark at room temperature (∼25 °C) in the absence of a typical chemical reductant. There was coordination between the Pd 0 nanoclusters and MMA-MAA, resulting in Pd 0 nanoclusters being stably and uniformly dispersed in the MMA-MAA matrix, with an average particle size of ∼2.5 ± 0.5 nm. Mechanistically, it can tentatively be proposed that PMMA-ionomerization of the Pd 2+ ions produces intramolecular -2COO - -Pd 2+ aggregate cross-links in the solution. On swelling of the chain-segments that are covalently bound via multiple C-C bonds, the resultant elastic forces cause instantaneous dissociation at the O-Pd coordination bonds to give transient bare ( i.e. , uncoordinated), highly-oxidative Pd 2+ ions and H + -associative carboxylate groups, both of which rapidly scavenge electrons and protons, respectively, of the active α-H atoms abstracted from the methanol molecules of the solvent to make Pd 0 nanoclusters supported by the re-formed MMA-MAA. The MMA-MAA acid copolymer, without itself undergoing any permanent chemical change, serves as a mechanical activator or catalyst for the mechanochemical reduction of Pd(CH 3 COO) 2 under mild conditions. Compared with traditional Pd/C catalysts, this Pd 0 nanocatalyst exhibited more excellent catalytic efficiency and reusability in the Heck reaction between iodobenzene and styrene, and it could be easily separated. The supported Pd 0 nanocatalyst prepared using this novel and simple preparation method may display high-efficiency catalytic properties for other cross coupling reactions., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)