Polymers

22 pages, 4903 KiB

Open AccessReview

Hybrid Materials Based on Self-Assembled Block Copolymers and Magnetic Nanoparticles—A Review

by Galder Kortaberria

Polymers 2025, 17(10), 1292; https://doi.org/10.3390/polym17101292 (registering DOI) - 8 May 2025

In this review work, the different routes and methods for preparing hybrid materials based on nanostructured block copolymers (BCPs) and magnetic nanoparticles (MNPs) are analyzed, as they can be potentially employed in different sectors like biomedicine, electronic or optoelectronic devices, data storing devices, etc. The first procedure for their preparation consists of the nanostructuring of BCPs in the presence of previously synthesized NPs by modifying their surface for increasing compatibility with the matrix or employing magnetic fields for NP orientation, which can also promote the orientation of nanodomains. Surface modification with surfactants led to the selective confinement of NPs depending on the interaction (mainly hydrogen bonding) degree and their intensity. Surface modification with brushes can be performed by three methods, including grafting from, grafting to, or grafting through. Those methods are compared in terms of success for the positioning and confinement of NPs in the desired domains, showing the crucial importance of brush length and grafting density, as well as of NP amount and modification degree in the self-assembled morphology. Regarding the use of external magnetic fields, the importance of relative amounts of MNPs and BCPs employed and that of the magnetic field intensity for the orientation of the NPs and the nearby BCP domains is shown. The second procedure, consisting of the in situ synthesis of NPs inside the nanodomains by a reduction in the respective metallic ions or employing metal-containing BCPs for the generation of MNP patterns or arrays, is also shown. In all cases, the transference of magnetic properties to the nanocomposite was successful. Finally, a brief summary of some aspects about the use of BCPs for the synthesis, encapsulation, and release of MNPs is shown, as they present potential biomedical applications such as cancer treatment, among others. Full article

(This article belongs to the Special Issue Advances and Applications of Block Copolymers II)

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19 pages, 1696 KiB

Open AccessArticle

Usability of Particles Made from Lesser-Used European Wood Species Mixed with Spruce Particles in the Particleboard Core Layer

by Roman Reh, Jan Izdinsky, Dominik Hrusovsky, Pavel Kral, Tomas Pipiska and Miroslav Jopek

Polymers 2025, 17(10), 1291; https://doi.org/10.3390/polym17101291 (registering DOI) - 8 May 2025

Abstract

The effects of produced wood particles from three wood species—alder, birch, and larch—added in various amounts in the particle mixture consisting of spruce particles and three tested wood species in a particleboard core layer on selected physical and mechanical properties of particleboard were studied. In a laboratory, 16 mm thick three-layer urea–formaldehyde (UF)-bonded particleboards were produced at 5.23 MPa, 240 °C, and with a 10 s/mm pressing factor. Two particleboard surface layers consisted of fine spruce particles. In the particleboard core layer, spruce particles were combined with particles from alder, birch, and larch. The tested particleboards containing alder, birch, and larch were characterized by approximately identical thickness swelling and they met the requirements of the conventional values stated by major particleboard manufacturers of 8–10%. The tested particleboard in all variations met the minimum strength value P2 particleboard in three-point bending, which is conventionally set at 11.0 MPa. The tested particleboard also exceeded the required values of modulus of elasticity in bending and internal bond strength. Analysis of the relationships demonstrated by the density profile confirmed that all three investigated wood species are usable in a mixture of core particles of high-quality particleboard in the recommended amounts (10, 15, 20%). Full article

(This article belongs to the Special Issue Wood-Based Composites: Materials, Manufacturing and Engineering)

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17 pages, 5531 KiB

Open AccessArticle

Eco-Friendly Polypropylene Composites Reinforced with Cellulose Fibers and Silica Nanoparticles

by Rinat M. Iskakov, Aigul S. Bukanova, Altynay S. Kalauova, Fazilat B. Kairliyeva, Alimzhan N. Nauashev, Gulbarshin K. Shambilova, Ivan M. Obidin, Mikhail S. Kuzin, Dmitryi N. Chernenko, Timofey D. Patsaev, Pavel S. Gerasimenko, Igor S. Makarov and Ivan Yu. Skvortsov

Polymers 2025, 17(10), 1290; https://doi.org/10.3390/polym17101290 (registering DOI) - 8 May 2025

Abstract

In this study, polymer composites based on a polypropylene (PP) matrix with the addition of cellulose and ES-40, used as a silica precursor, were investigated. These composites were designed to achieve enhanced biodegradability through the incorporation of bioavailable cellulose and to enable subsequent carbonization into carbon–silicon carbide systems. Rheological investigations revealed that the multicomponent mixtures exhibited pseudoplastic behavior over the shear rate range typical of injection molding, ensuring process stability without additional plasticization. Morphological analysis demonstrated that an optimal balance of PP, cellulose, and ES-40 promoted the formation of a three-dimensional network structure, leading to a significant increase in flexural modulus at the equal flexural strength despite some reduction in tensile strength. It was further shown that substituting fibrous cellulose with microcrystalline cellulose improved the composite homogeneity, thereby enhancing the density and mechanical properties, especially in systems with low polymer contents. Preliminary pyrolysis experiments indicated that these injection-molded composites can serve as precursors for fabricating bulk thermally stable products containing silicon carbide particles. The obtained results underscore the high potential of the developed materials for applications in conventional injection molding, the possibility of additive manufacturing, and processes requiring subsequent carbonization. Full article

(This article belongs to the Special Issue Development in Carbon-Fiber-Reinforced Polymer Composites)

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Polymers, Volume 17, Issue 10 (May-2 2025) – 3 articles

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