Transition Metal-Catalyzed Functionalization of Polyolefins Containing CC, CC, and CH Bonds

Characterization and Performance Enhancement of Bio-Based Polyurethane-Modified Cement Mortar Utilizing Polyglycerol Polyester Polyol

The increasing focus on sustainable construction is driving the industry toward materials that combine functionality with environmental benefits. A viable approach to address this demand is the use of bio-based additives to improve traditional cementitious composites. This study introduces a novel approach to developing a polymer-modified construction material by incorporating varied amounts (0, 1, 2, 3, and 6%) of bio-based polyurethane (PU), derived from polyglycerol polyester polyol, into cementitious mortar. The resulting PU-modified cementitious mortar (PUMC) was evaluated for its mechanical, physicochemical, and microstructural properties. Results show that the incorporation of 2% PU by cement weight significantly enhanced compressive strength by 58.2%, flexural strength by 37.0%, and initial flow performance by 20.0% after 28 days, while a 6% PU incorporation provided the best abrasion resistance. These improvements were attributed to a uniform particle and pore size distribution and the formation of a uniform interpenetrating polymer network (IPN), as confirmed by BET-BJH and SEM-EDX analyses. Additionally, FTIR and TGA analyses revealed that the metal-ligand coordination between Ca2+ ions in the cement mortar and PU ligand groups strengthened the interfacial connectivity through noncovalent bonding, further enhancing the material properties. This research highlights the potential of bio-based PU as an eco-friendly additive that significantly improves the performance of cementitious mortars, making it a promising option for industrial flooring applications.

Characterization of microplastic-derived dissolved organic matter in freshwater: Effects of light irradiation and polymer types

This study investigated the impacts of light irradiation and polymer types on the leaching behavior of dissolved organic matter (DOM) from microplastics (MPs) in freshwater. Polypropylene had the highest leaching capacity of DOM after photoaging, followed by polystyrene (PS), polyamide (PA) and polyethylene terephthalate (PET). While similarly low levels of DOM were observed in the remaining 5 MP suspensions under UV irradiation and in almost all MP suspensions (except PA) under darkness. These suggest that the photooxidation of some buoyant plastics may influence the carbon cycling of nature waters. Among 9 MP-derived leachates, PET leachates had the highest chromophoric DOM concentration and aromaticity, probably owing to the special benzene rings and carbonyl groups in PET structures and its fast degradation rate. Protein-like substances were the primary fluorescent DOM in MP suspensions (except PS), especially in darkness no other fluorescent substances were found. Considering the bio-labile properties of proteins together, MPs regardless of floating or suspended in an aquatic environment may have prevalent long-term effects on microbial activities. Besides, from monomers to hexamers with newly formed chemical bonds were identified in UV-irradiated MP suspensions. These results will contribute to a deep insight into the potential ecological effects related to MP degradation.

Laser-Assisted Structuring of Graphene Films with Biocompatible Liquid Crystal Polymer for Skin/Brain-Interfaced Electrodes

The work presented here introduces a facile strategy for the development of flexible and stretchable electrodes that harness the robust characteristics of carbon nanomaterials through laser processing techniques on a liquid crystal polymer (LCP) film. By utilizing LCP film as a biocompatible electronic substrate, control is demonstrated over the laser irradiation parameters to achieve efficient pattern generation and transfer printing processes, thereby yielding highly conductive laser-induced graphene (LIG) bioelectrodes. To enhance the resolution of the patterned LIG film, shadow masks are employed during laser scanning on the LCP film surface. This approach is compatible with surface-mounted device integration, enabling the circuit writing of LIG/LCP materials in a flexible format. Moreover, kirigami-inspired on-skin bioelectrodes are introduced that exhibit reasonable stretchability, enabling independent connections to healthcare hardware platforms for electrocardiogram (ECG) and electromyography (EMG) measurements. Additionally, a brain-interfaced LIG microelectrode array is proposed that combines mechanically compliant architectures with LCP encapsulation for stimulation and recording purposes, leveraging their advantageous structural features and superior electrochemical properties. This developed approach offers a cost-effective and scalable route for producing patterned arrays of laser-converted graphene as bioelectrodes. These bioelectrodes serve as ideal circuit-enabled flexible substrates with long-term reliability in the ionic environment of the human body.

Highly Versatile Strategy for the Production of Telechelic Polyolefins

A general and versatile synthetic strategy for producing practical quantities of a wide range of phenyl-group-terminated hetero- and homotelechelic semicrystalline polyethenes and amorphous atactic and semicrystalline isotactic poly(α-olefins) is reported. The phenyl groups serve as synthons for functionalities of additional classes of telechelic polyolefins that can be "unmasked" through simple high yielding postpolymerization reactions. A demonstration of the value of these materials as building blocks for structural classes of polyolefin-based synthetic polymers was provided by syntheses of well-defined polyolefin-polyester di- and triblock copolymers that were shown to adopt microphase-segregated nanostructured mesophases in the condensed phase.

The effect of organosilicon modifier structure on the efficiency of the polybutadiene hydrosilylation process

Real-time FT-IR spectroscopy permitted us to determine the influence of steoelectronic properties of functional groups on hydrosilylation. This allowed the synthesis of polybutadienes equipped with attractive silicon-based functional groups.

Synthesis of Ultrahigh Molecular Weight Polymers Containing Reactive Functionality with Low PDIs by Polymerizations of Long-Chain α-Olefins in the Presence of Their Nonconjugated Dienes by Cp*TiMe2(O-2,6-iPr2C6H3)-Borate Catalyst

Copolymerizations of 1-decene (DC) with 1,9-decadiene (DCD), 1-dodecene (DD) with 1,11-dodecadiene (DDD), and 1-tetradecene (TD) with 1,13-tetradecadiene (TDD), using Cp*TiMe₂(O-2,6-ⁱPr₂C₆H₃) (1)–[Ph₃C][B(C₆F₅)₄] (borate) catalyst in the presence of AlⁱBu₃/Al(n-C₈H₁₇)₃ proceeded in a quasi-living manner in n-hexane at −30 to −50 °C, affording ultrahigh molecular weight (UHMW) copolymers containing terminal olefinic double bonds in the side chain with rather low PDI (M_w/M_n) values. In the DC/DCD copolymerization, the resultant copolymer prepared at −40 °C possessed UHMW (M_n = 1.40 × 10⁶ after 45 min) with low PDI (M_w/M_n = 1.39); both the activity and the PDI value decreased at low polymerization temperature (M_n = 5.38 × 10⁵, M_w/M_n = 1.18, after 120 min at −50 °C). UHMW poly(TD-co-TDD) was also obtained in the copolymerization at −30 °C (M_n = 9.12 × 10⁵, M_w/M_n = 1.51, after 120 min), using this catalyst.