Macromolecular Materials and Engineering最新文献

The polyethylene oxide-polypropylene oxide (PEO-PPO) based triblock copolymers are notable amphiphilic copolymers with a diverse range of applications. The presence of homo-, and/or diblock impurities in copolymers with PEO-PPO-PEO triblock has been demonstrated. This finding suggests that the samples are blends rather than pure triblock copolymers. Furthermore, copolymers with triblock copolymer content of 0 or less than 20% by molar percentage have been identified. The hydrophilic-lipophilic balance (HLB) is also calculated based on the exact composition of the blends. The effect of HLB values and compositional data on the initial foam height (in casein solution), the surface tension, and the contact angle are investigated. The correlation coefficients for the PPO-PEO-PPO copolymers versus HLB values are found to be high, while those obtained for the PEO-PPO-PEO copolymers versus values of HLB are significantly lower. The lower correlation coefficients for the PEO-PPO-PEO samples can be attributed to the presence of homo- and diblock (co)polymer contaminants. In addition, a linear regression model has been constructed to find a mathematical relationship between the percentage of ethylene oxide, the average number of propylene oxide units, and the properties of the copolymer.

Gelatin methacrylate (GM) and sodium alginate (SA) are two biomaterials that have been widely employed in tissue engineering, particularly in 3D bioprinting. However, they have some drawbacks including undesirable physico-mechanical properties and printability, hindering their application. This work developed an interpenetrating polymeric network (IPN) of GM and SA reinforced with silica nanoparticles (SNPs) to deal with hydrogels’ drawbacks. Besides, for cross-linking, visible light is used as an alternative to UV light to prevent disruptions in cellular metabolism and immune system reactions. Four GM/SA/SNP hydrogels different in SNPs concentration (0, 0.5, 1, and 2 w/w%) are studied. The performance of the hydrogels is evaluated in terms of physico-mechanical properties (viscoelasticity, compressive modulus, degradation, and swelling), rheological properties, and biological properties (fibroblast cell growth and adhesion, and MTT assay). The results demonstrated that the GM/SA/SNP hydrogel with 1% SNPs provided desirable physical (645% swelling and 59.3% degradation), mechanical strength (270 kPa), rheological (tan δ of almost 0.14), and biological performances (≈98% viability after 3 days) while maintaining appropriate printability. The findings suggest that the GM/SA/SNP hydrogel holds great potential for applications in soft tissue regeneration.

As environmental problems increase, disposable products are being replaced and recommended with materials with a low environmental load when it discarded. So the demand for bioplastics for building a sustainable society is increasing. This study focuses mainly on the applicability of biodegradable plastics and rosin maleic resin (RMR, DX-250) blends with potential use in eco-friendly hot-melt adhesives (HMA). Poly (butylene adipate-co-terephthalate) (PBAT), which has high dimensional stability owing to low crystallinity, is used as the main polymer of the HMA. And rosin maleic resin, which is effective for increasing adhesive properties and compatibility as a tackifier. The HMA based on PBAT and RMR blends are prepared via melt-blend extrusion. Compatibility and wettability are increased under the influence of RMR, and adhesion properties are improved, compared to that of PBAT. In addition, as confirmed polarizing microscope (POM), the addition of RMR leads to a decrease in crystallinity, which can be expected to be effective for biodegradation. This result PBAT/RMR 7/3 blend significantly enhances the adhesion strength of PBAT from 1.8 to 7.3 MPa. Therefore, PBAT with the blends containing 30 wt.% of RMR has considerable potential application in the HMA field.

Front Cover: Taking the advantage of hydrophobic nature of PLGA and branched structure of POEGMEMA, enables to get physically cross-linked scaffolds. Physical cross-linking is achieved by aggregation of PLGA in aqueous media and formation of intra- and inter-molecular entangles between aggregated PLGA and branched POEGMEMA polymers. Thus, though high hydrophilic POEGMEMA content, robust polymeric scaffolds are obtained without using toxic reactions. More details can be found in article 2400112 by Elif Kaga and Sadik Kaga.

A three-step synthetic route is established for the synthesis of a phosphorus-containing ε-caprolactam derivative, starting from cyclohex-2-enone and diphenylphosphinous chloride, followed by a Beckmann rearrangement. 2D NMR spectroscopy reveals that the phosphorus moiety is selectively localized at the 4-position of the caprolactam ring. Different amounts of the phosphorus-containing comonomer are systematically incorporated into polyamide 6 by anionic ring-opening copolymerization with ε-caprolactam at elevated temperatures. Polymerization reactions are initiated by a latent, CO₂ protected N-heterocyclic carbene in the presence of N-acetyl caprolactam and MgCl₂. The phosphorus content is determined by inductively-coupled plasma-optical emission spectroscopy (ICP-OES) analysis. Limiting oxygen indices up to 23.5 are found for polymers containing ≈1 wt.-% of phosphorus. The thermal properties of the copolymers are determined and compared to those of polyamide 6.

Multilayer polymer films are extensively used in multiphase separation. Electrospray deposition (ESD) is an important technique for fabricating such films with tunable morphology. Viscoelastic properties of polystyrene (PS) nanoshell coatings produced by ESD on gold and spin-coated PS surfaces are evaluated using Quartz Crystal Microbalance with Dissipation (QCM-D). The thickness of PS films on gold increases with flow rate from ∼200 nm at 0.5 to ∼400 nm at 1.5 mL h⁻¹, accompanied by an order-of-magnitude increase in dissipation due to larger particle sizes from shorter droplet flight times. This effect is absent on spin–coated PS films, suggesting the onset of the self-limiting effect of charges. Although the shear moduli for ESD films calculated from Voigt models is only 0.08%–0.20% of the bulk PS modulus, the stiffness ratio of spray-coated PS to a single shell is (5.00–13.3) × 10³ m⁻¹, due to shell–shell and shell–substrate interactions. These are novel results related to the interparticle friction obtained using QCM-D for the first time. This work demonstrates  that mechanical properties of particulate viscoelastic films with potential applications in high surface area sensors, such as size-selective membranes for protein or electrolyte adsorption, can be evalauted by QCM-D with nanograms of material.

Like skeletal muscles having a fibrous structure, conducting polymers can actuate upon electrical stimulation and can be shaped into fibers. Through textile assembly strategies of such fibers, complex actuating architectures are possible. However, state-of-the-art strategies using short pieces of yarn, which compel manual integration, are not fully taking advantage of textiles. To manufacture actuating textiles that best exploit textile properties like softness and pliability, and to enable production upscaling, a production of continuous, actuating fibers is presented here. These fibers are produced from commercial polyamide 6/6 filaments by first continuously dip-coating in a modified commercial poly(3,4−ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) dispersion before the electropolymerization of polypyrrole (PPy), where the fibers are withdrawn continuously through an electrolyte solution containing the pyrrole monomer. By employing a cyclic dip-coating with individual viscosity, drying temperature, and withdrawal speed for each layer, and by adjusting the tension, speed, and applied potential of the electropolymerization, their isotonic strain is enhanced threefold. Their specific tension, at 400 µN tex⁻¹, reaches slightly higher than human skeletal muscle fibers. Furthermore, these continuous actuating fibers produced on the meter are processable in an industrial knitting machine. This study anchors the development of textile muscle fibers for future textile muscles.

PEGylation Effects on the Interaction of Sphingomyelin Nanoemulsions with Serum Albumin: A Thermodynamic Investigation. Macromol. Mater. Eng. 2023, 308, 2200622. https://doi.org/10.1002/mame.202200622

In the “Acknowledgements” section, the following acknowledgement was missing: “Horizon 2020 Framework Program Project: 814607 – SAFE-N-MEDTECH.”

We apologize for this error.

Front Cover: A novel core-sheath fiber structure made using pressurized gyration and where the thin sheath is loaded with garlic (Allium Sativum) eliminates bacteria. This is demonstrated by comparing the top half of the micrograph with the bottom half where the bacteria are virtually absent. The exploitation of natural materials like garlic in this way paves the way for a new generation of economical but very effective and safe wound healing patches. More details can be found in article 2400014 by Mohan Edirisinghe and co-workers.