Kamila Mizera

The fire performance of hybrid epoxy composites depends on both the flame-retardant system and the reinforcement architecture. This study investigates the effects of different combinations of synthetic and natural fabrics and functional fillers on the fire behavior, thermal degradation, smoke production, and combustion products of epoxy composites containing 10 wt.% expandable graphite (EG) and 10 wt.% ammonium polyphosphate (APP). A glass-fiber-reinforced composite was used as the reference. The materials were characterized by cone calorimetry, smoke density measurements, horizontal burning tests, thermogravimetric analysis (TG/DTG), differential scanning calorimetry (DSC), simultaneous thermal analysis coupled with Fourier-transform infrared spectroscopy (STA/FT-IR), and combustion-effluent analysis using a Purser furnace coupled with a Gasmet DX4000 gas analyzer. Significant differences in fire performance were observed among the formulations. VACMGBHF exhibited the longest time to ignition (206 s), the lowest peak heat release rate (79 kW·m⁻²), and the lowest maximum mass-loss rate during the principal thermo-oxidative degradation stage (2.03%·min⁻¹). It also retained 38.8% of its initial mass at 900 °C, the highest value among the hybrid composites. In contrast, ACGBF showed the lowest average heat release rate (8 kW·m⁻²), maximum average rate of heat emission (20 kW·m⁻²), and total heat release (4 MJ·m⁻²). Smoke production also depended on composite composition. The lowest maximum specific optical density was recorded for the glass-fabric reference (42), whereas ACGBF exhibited the lowest total smoke release (123 m²·m⁻²). Visual examination revealed differences in the continuity and morphology of the post-combustion residues, with several hybrid formulations forming expanded, cohesive carbonaceous–mineral layers. TG/DTG, DSC, and STA/FT-IR analyses further demonstrated formulation-dependent degradation behavior and evolved-gas profiles. All composites achieved the HB classification in the horizontal burning test. The findings demonstrate that reinforcement architecture and filler composition influence heat release, smoke generation, and thermal stability in different ways, highlighting the need to evaluate these parameters together when designing flame-retardant epoxy composites.

Despite their high effectiveness in reducing material flammability, modern brominated flame retardants (BFRs) remain poorly understood with respect to the toxic substances they generate during combustion. BFRs such as 1,2-bis(pentabromodiphenyl)ethane (DBDPE) and tetrabromophthalate diol (PHT4-DIOL) have been introduced following the limitations on legacy brominated additives. However, their thermal decomposition pathways and toxic product emission profiles under real fire conditions remain poorly characterized. Exposure to elevated temperatures may promote the formation of halogenated toxicants and environmentally persistent compounds, raising concerns that extend beyond conventional fire-safety performance. The combustion behavior of DBDPE-, PHT4-DIOL-, and BFR-containing epoxy resins was investigated using a steady-state tube furnace designed to reproduce realistic fire scenarios. Controlled temperature and ventilation conditions were applied to simulate representative stages of fire. Combustion emissions were comprehensively characterized using Fourier transform infrared spectroscopy (FT-IR) to analyze asphyxiant and irritant gases and solid-phase microextraction gas chromatography–mass spectrometry (SPME-GC-MS) for volatile and semi-volatile organic compounds. The results presented that the incorporation of BFRs substantially altered combustion emission profiles, promoting the formation of brominated and mixed-halogenated species alongside toxic gaseous products. Significant differences in the composition and distribution of combustion byproducts were observed between non-modified and BFR-containing materials, indicating that the environmental and toxicological consequences of these additives cannot be adequately assessed solely through flammability-reduction metrics. These conclusions provide new knowledge of the environmental impacts of brominated flame retardants and highlight the importance of integrated fire-safety assessment strategies that simultaneously consider flame-inhibition efficiency, combustion toxicity, and environmental persistence.

In the quest for climate neutrality, the importance of sustainability and the reuse of wood waste are becoming crucial. To determine how wood waste is managed by wood and wood-based panel plants, the research aimed to focus particularly on energy recovery contribution. The research was based on quantitative data analysis obtained through computer-assisted telephone interviews. The results showed that over 57 % of respondents declared that they combusted waste to recover energy, which causes immediate CO2 emissions, instead of enabling long-term storage in wood-based products. Further research analyzed the emissions produced by combustion of the selected products: MDF boards and softwood and hardwood pellets. Laboratory tests showed that the incineration of MDF boards resulted in the emission of a number of harmful substances, which pose a threat to health and the environment. In contrast, burning pellets does not generate toxic compounds, but it still leads to the release of CO2. Research findings indicate the need for further research into the cascading wood utilization strategy, focusing on the use of wood waste in the material cycle instead of the energy cycle in order to understand and promote the EU’s sustainable development goals throughout the wood industry.

The development of technology and newer requirements for materials leads to an increase in their production and storage. In the past, serious fires have occurred in public buildings, residential buildings, industrial halls, and warehouses where plastics were used or produced, resulting in disastrous consequences for the environment and human health. For this reason, it is important to examine the risks to people and the environment that arise during a fire in places where these materials are located and stored. Polyurethane foams (PUF) used in building insulation and the automotive industry have been analyzed to determine their flammability and smoke emission during combustion. The thermal stability of PUFs was assessed using simultaneous thermal analysis (STA). Released gases were identified using STA combined with FT‐IR (STA/FT‐IR). Fire resistance and smoke emission during combustion were evaluated using cone calorimetry and a smoke chamber. Differences in thermal decomposition and combustion characteristics, including smoke release, were observed. The combustion of semi‐rigid foam was accompanied by the lowest total smoke release and the lowest total heat release. However, the combustion of flexible foam was characterized by the highest amount of smoke and a high rate of heat release, despite only a 5% weight loss at the highest temperature. In the case of rigid foam, a large residue in the form of a carbonized layer was observed.

The study examined the degradation process of various types of polymers used to form models using the fused deposition modeling (FDM) and three-dimensional printing (3DP) methods and used in the investment casting method. Commercial filaments made of polylactide (PLA), acrylonitrile butadiene styrene terpolymer (ABS), high-impact polystyrene (HIPS), polyamide 12 (PA12), poly(methyl methacrylate) (PMMA), and polypropylene (PP) were used to produce gypsum molds. The assessment included organic volatile compounds (VOCs) released during mold heating and model degradation, which is characteristic of this technological process. The screening qualitative chromatographic analysis of decomposition products sampled from various points of the production hall made it possible to define potential threats related to the processing of selected polymers and the necessary preventive measures. Furthermore, passive diffusion-type samplers were used at the sampling stage of VOCs emitted to the gaseous phase to reduce nuisance and user interference. Studies have been completed to characterize the thermoplastic polymer degradation process. The coupled thermogravimetry (TGA) with analysis of gaseous products by infrared spectroscopy with Fourier transformation (FT-IR) has been used. The presented results are the first to compare and rate the use of this still-developing novel aspect of castings by the method of fused models. Graphical abstract

Validation of methods for assessing the properties of anti-vandal hybrid composites modified with inorganic and plant fillers, with reduced flammability and smoke emission and high resistance to vandalism, intended for use in public transport, was carried out. Four standardized procedures, intended for testing personal protective equipment (protection of upper and lower limbs), including impact, and cut resistance and flame resistance, were modified. Since the tested materials were to be used in applications beyond the scope of the original test procedures, each method required re-validation. In this work, systematic and random errors of measurements that could affect the reliability and validity of the methods were identified. Therefore, individual uncertainty components, which characterize the dispersion of values assigned to the measured quantity at a given probability level, were precisely determined and then combined into uncertainty budgets for individual methods. After the validation, the methods can be successfully used to assess anti-vandal composite materials in the context of resistance to vandalism in public transport.

Spalanie i rozkład termiczny żywicy epoksydowej (EP) i żywicy epoksydowej z melaminą (EP/ME) zbadano za pomocą kalorymetru stożkowego i analizy termograwimetrycznej sprzężonej ze spektroskopią w podczerwieni z transformacją Fouriera (STA/FT-IR). Badanie wykazało, że zastosowanie melaminy w EP, jako środka ograniczającego palność, prowadziło do powstania warstwy zwęglonej na powierzchni spalanej próbki. W konsekwencji tego zmniejszała się maksymalna szybkość wydzielania ciepła oraz całkowita ilość wydzielanych dymów. Podczas analizy STA/FT-IR obserwowano wydzielanie się mniejszej ilości tlenku węgla dla EP/ME.

Our research material comprised antivandal fire-retardant hybrid composites modified with inorganic and organic fillers intended for application in public transport vehicles. This paper presents an approach to studying their impact strength as a function of the composite thickness (3 to 6 mm) and striker shape (hemispherical, semicylindrical, wedge-shaped) used in the experimental stand. Group A composites, made of single fabric layers (n = 5), were thinner and their impact strength was lower by 73% than that for Group B composites made of double fabric layers. Study results show an almost threefold improvement in impact strength for a thickness increase of as little as 0.3 mm. Statistical analysis (the Shapiro–Wilk test, p > 0.05) did not show any significant differences in the quantitative evaluation of changes (n = 3) on the surface of the examined materials caused by impacts with strikers of different shapes. In turn, a linear correlation (Shapiro-Wilk test, W = 0.0857, p = 0.022) was found between impact strength and the thickness of the studied materials. It was observed that appropriate arrangement of fabrics and powder fillers can lead to a different distribution of forces and energy absorbed by the tested material. A lower impact strength was observed for the composite which had powder fillers in its composition, which caused the formation of microvoids in the structure of the material and thus led to a weakening in their strength properties. An effect of the placement of the glass fabric layer in the composite on the results was also observed. Moreover, SEM evaluation of the composites revealed their layered structure and the impregnation of woven fabrics with resin.

Zbadano właściwości czterech popularnych płyt drewnopochodnych dostępnych na rynku pod kątem ich palności i ilości powstającego dymu. Parametry palności zostały określone za pomocą kalorymetru stożkowego, a właściwą gęstość optyczną powstałego dymu oceniono z wykorzystaniem komory do badania dymotwórczości. Zaobserwowano, że palność oraz emisja dymu badanych płyt zależała od sposobu ich wytworzenia. Zmniejszenie parametrów określających palność materiałów było obserwowane dla płyt ogniouodpornionych. Emisja dymów określana na podstawie badania kalorymetrycznego zależała od zadanego strumienia ciepła. Z kolei emisja i gęstość dymu określana w badaniu prowadzonym w komorze do badania dymotwórczości była niższa dla płyt ogniouodpornionych