In response to the growing need to reduce reliance on petrochemical feedstock and eliminate toxic isocyanates in polyurethane production, this study presents the synthesis of composite non-isocyanate polyurethane (NIPU) foams...

Intumescent flame-retardant coatings on polyurethane foam via layer-by-layer assembly: the role of assembly sequence in enhancing performance

Activated carbon fiber as a passive air sampler for monitoring phthalate exposure in university dormitories: Performance calibration and risk assessment.

Volatile organic compounds (VOCs) are a major occupational concern in polyurethane foam production, where exposure may impact worker health. This study identified key VOCs and evaluated their concentrations across different sections of a polyurethane manufacturing facility. Area (n = 5) air samples were collected during routine full-load production using short-duration active sampling and analyzed by thermal desorption gas chromatography-mass spectrometry (TD-GC-MS). The results revealed marked spatial variability in VOC concentrations, with the curing section showing the highest totals. Dichloromethane (DCM) constituted the dominant VOC in high-emission zones. All measured concentrations of DCM and other regulated substances remained well below European and Polish short-term exposure limits. Quantitative health risk assessment demonstrated that lifetime cancer risk values for DCM and benzene were in the 10-6 range, far below the regulatory threshold of concern (10-4). Non-carcinogenic risk indices (HQ) were generally low; however, a markedly elevated HQ was identified for 1-hexanol, 2-ethyl- in the cutting area (HQ = 5.7), indicating a potential localized non-cancer health concern. Overall, existing protective measures appear effective, but additional targeted precautions are warranted in zones with elevated emissions. Enhanced ventilation, strengthened personal protective equipment, and routine air monitoring are recommended to minimize potential health risks. Regular updates of occupational safety standards should reflect evolving toxicological evidence to ensure sustainable protection of workers in polyurethane foam production.

With the rising demand for sustainable materials, lignin-based polyols offer a promising renewable alternative to traditional petroleum-based polyols in flexible polyurethane (PU) foams. This study focuses on synthesizing novel high-performance lignin-based polycarbonate polyols via transesterification with dimethyl carbonate. The resulting lignin polyols exhibited hydroxyl values ranging from 111 to 179 mg KOH/g and viscosities of 12,000-26,000 mPa·s, thereby enhancing the suitability of lignin for flexible foam formulation. An in-depth structural analysis using proton, carbon, phosphorus, and 2D nuclear magnetic resonance confirmed the grafting of long polyether chains and the introduction of multiple carbonate linkages onto the lignin structure. Foams were formulated by replacing up to 60% of petroleum-based polyols with either synthesized lignin polyol or a mixture of lignin and soy polyols. Formulated foams demonstrated superior mechanical properties, including enhanced tensile strength and load-bearing capacity, compared to petroleum-based foams. Additionally, the developed foams with biobased polyols exhibited improved thermal stability, shock absorption, and partial biodegradability.

Polyurethane foam stakeholders are currently facing stringent regulatory constraints, such as the REACH regulation restricting the use of isocyanates and increasing environmental pressures calling for more sustainable materials. This dual challenge compels both academia and industry to innovate and redesign conventional PU chemistry and foaming toward non-isocyanate solutions while integrating eco-design principles to enhance recyclability and circularity. This tutorial review summarizes the current advances in synthetic strategies for producing non-isocyanate polyurethanes (NIPUs), with a particular focus on foaming concepts, which have witnessed a significant acceleration in development over the last five years. Emerging end-of-life management solutions via chemolysis or physical means - exploiting covalent adaptable network features - and applications of NIPU foams are also discussed. For each aspect, a comparative analysis between conventional PU and NIPU highlights the remaining technological, environmental and economic challenges that must be addressed to achieve competitive, scalable, and sustainable NIPU foams.

A heterogeneous hydrogel patch with mechanical activity and bioactivity for chronic diabetic wound healing.

Biomimetic intensified NH/CH···π interaction via metal oxide-mediated interfacial polarization for robust nanoplastics capture by polyurethane foam.

The pervasive contamination of water resources by heavy metal ions poses serious threats to environmental safety and human health, creating an urgent demand for simple, sensitive, and selective sensing platforms. Herein, a robust polyurethane foam (PUF)-supported UiO-66-NH2-calcein composite is developed as a solid-state fluorescent sensor for the selective detection of Cu2+ ions in aqueous media. The immobilization of calcein within the porous UiO-66-NH2 framework and its subsequent integration into a PUF matrix provides a stable, highly accessible, and reusable fluorescence platform. Structural and spectroscopic characterization confirms the successful formation and homogeneous distribution of the composite components. Fluorescence screening against a series of metal ions demonstrates that, although several ions can interact with the sensor, a markedly enhanced and selective fluorescence response toward Cu2+ is achieved under mildly acidic conditions (pH 5). The sensor exhibits a linear fluorescence response toward Cu2+ over the micromolar concentration range with a low detection limit of 0.011 µM. The composite also exhibits mechanical integrity and operational reusability, with no significant signal loss. The foam-based architecture enables rapid mass transfer, improved light penetration, and convenient handling, making the platform well-suited for portable and on-site water analysis. This work presents an effective strategy for constructing MOF-polymer fluorescent composites for selective Cu2+ sensing and practical environmental monitoring. The PUF/UIO-66-NH-calcein nanocomposite exhibits remarkable fluorescence sensitivity toward multiple metal ions at pH 7, achieving ultra-low limits of detection of 0.0013 µM for As3+, 0.0049 µM for Cd2+, 0.009 µM for Zn2+, 0.0049 µM for Cu2+, and 0.0081 µM for Ca2+, while maintaining stable performance under aqueous conditions.

A novel pre-foaming strategy to manipulate carbon dioxide adsorption and desorption behavior for achieving low-density TPU foams

The Open-cell Al foam (OCAF) with an average density of 0.12 g/cc were synthesized successfully through reticulation technique, using polyurethane (PU) foam as a precursor. For further enhancing the multifunctional properties of OCAF, here in this work it is reinforced with red mud and cenospheres. The addition of red mud and cenosphere reinforcements in OCAF at 10% by weight is studied to analyze their effect on microstructure, mechanical strength and electromagnetic wave (EMW) absorption of the foam. The EMW absorption was evaluated using a Vector network analyzer in X-Band (i.e. 8.2 -12.4 GHz) frequency range. OCAF with cenosphere shows the highest total shielding effectiveness (~28 dB) which is then followed by red mud reinforcement and bare OCAF. In cenosphere, absorption component dominates the total shielding. Whereas in red mud, reflection and absorption contribute almost equally in total shielding. This reinforcement also enhances the compressive strength and energy absorption of the OCAF structure. The result demonstrated the use of cenosphere and red mud to tailor the properties of OCAF in terms of EMW absorption and structure application for the development of new material for electromagnetic shielding.

A bionic superhydrophobic method was conducted by combining hydrophobic modification of three‐dimensional (3D) and two‐dimensional (2D) materials with surface nanostructure regulation. Polydimethylsiloxane (PDMS)‐modified nanosilica (SiO 2 ) was utilized with heteroatom‐functionalized aminosilane (KH550) as a key coupling agent to prepare a uniformly dispersed PDMS/SiO 2 composite solution, which was then coated onto 3D polyurethane (PU) foam and 2D cellulose membranes (CF) to mimic the “lotus leaf” micro–nano papillary structure. A homogeneous nanoscale rough surface was achieved on the modified material, with a water contact angle of 152.3° and an oil contact angle approaching 0°, demonstrating exceptional superhydrophobicity and superoleophilicity. Separation experiments indicated selective adsorption of organic solvents typical in pharmaceutical processes, with a dichloromethane adsorption capacity of 21.07 g/g. After 10 adsorption‐squeezing cycles, the material retained over 85% of its initial adsorption capacity, highlighting its durability. This study provides a cost‐effective and environmentally friendly approach for developing high‐efficiency materials for the removal and recovery of organic solvents from aqueous streams in pharmaceutical manufacturing and wastewater treatment.

• Non-innocent structured support for Pd catalysis. • Structured support based on tannin-coated open cell polyurethane foams. • Selective alkyne semi-hydrogenation and nitroarene reduction. • Suzuki coupling under air. • Convenient reusability in a “dip-and-play” mode in batch. Polyurethane foams (PUF) were coated with hydrolyzable (HT) or condensed (CT) tannins, derived from chesnut and quebracho woods, and Pd was anchored onto the HT or CT layer via simple immersion of HT@PUF and CT@PUF in a water-ethanol (1:5) solution of Pd(NH 3 ) 4 Cl 2 ⋅H 2 O at room temperature under air to afford Pd@HT@PUF and Pd@CT@PUF composites. XPS showed a partial reduction of the Pd(II) salt to Pd(0) in agreement with the reducing properties of the HT and CT coatings, and SEM and SEM-EDX suggested a coordination of evenly dispersed Pd(II) ions by the phenol moieties of the HT or CT layer together with the formation of Pd (nano)particles. The palladium loading, as determined by ICP-AES measurements, varied with the concentration of the aqueous tannin solution (0.1 or 0.5 g/L) used for the HT or CT coating procedure; the higher the concentration, the higher the Pd loading. A high loading of Pd, hence of Pd(0), on the as-synthesized macroscopic catalyst guaranteed a stable catalytic activity and selectivity from the beginning without prior activation procedure in alkyne-to-alkene hydrogenation. A lower Pd loading resulted in a gradual improvement of the catalytic activity overtime that conincidated with a reduction of the chelated Pd(II) ions to Pd(0) under the reaction conditions. Notably, both Pd@HT@PUF and Pd@CT@PUF proved reusable for at least 6 cycles without significant catalyst activity and selectivity decrease, in a convenient “dip-and-play” mode, in selective alkyne semi-hydrogenation and/or nitroarene reduction, as well as in fast Suzuki coupling under air.

Insights on natural degradation in fully aliphatic biodegradable polyurethane foams

Microalgae-derived polyurethane (Bio-PU) and non-isocyanate polyurethane (Bio-NIPU) present reduced greenhouse gas emissions and fossil energy consumption compared to conventional polyurethane.

Effect of registration methods on accuracy and efficiency of dynamic computer-assisted implant surgery: An in vitro study.

Study on the densification drilling mechanism and evaluation system of polyurethane foam as a simulated material for alveolar bone

Flame-retardant rigid polyurethane foam composites based on copper tailings and melamine polyphosphate: a novel strategy for copper tailings utilization

Thermoplastic polyurethane foam with superior expansion ratio and mechanical properties by cross-linking modification and supercritical fluid foaming

Cardanol/triazine-based polyol and DOPO derivative for thermally insulating and flame retardancy rigid polyurethane foam composites