PLA is widely known as biodegradable plastics whose further application in fields such as automotive and architectural is still constrained by its flammability and unsatisfactory crystallization ...properties. To address the aforementioned concerns, a novel biomass phosphonamide PDPA was synthesized with chemical structure confirmed by FTIR, NMR and elemental analysis tests. Immediately thereafter, PLA/PDPA composites were prepared by melting blending, with a focus on flame retardancy, crystallization properties and flame-retardant mechanism. As expected, PDPA efficiently enhanced both the flame retardancy and crystallization properties of PLA. Specifically, the PLA/4.0PDPA obtained UL-94 V-0 grade and the LOI value increased to 28.6 % with only 4 wt% PDPA added, which comes down to the superior free radical capture and dilution effect of PDPA in the vapor phase and the melting droplet effect. More appealingly, the crystallinity of PLA/4.0PDPA was significantly enhanced to 43.4 % from 2.5 % of PLA, and the shortest t1/2 was 4 mins in the isothermal crystallization process due to the excellent heterogeneous nucleation of PDPA. Moreover, PLA/PDPA composites maintain almost the same mechanical performance as pure PLA. In brief, this work provides a green strategy for the preparation of PLA composites with excellent comprehensive performance and shows great potential in engineering materials.
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•A novel biomass phosphamide was successfully synthesized.•PDPA endowed PLA favorable flame retardancy and crystallization properties concurrently.•PLA/PDPA composites retained salient chroma and processing performance.•PLA/PDPA composites achieved an effective balance of properties.
•Black phosphorene was successfully coordinated by a ruthenium sulfonate ligand.•Excellent stability in environment was obtained.•Dramatically improved flame-retardant efficiency was ...achieved.•Significantly enhanced thermal conductivity with small amount.
Black phosphorus (BP) are shining for its promising properties. Due to the instability and agglomeration problem, the surface coordination strategy is a key point in practical applications. Herein, a ruthenium sulfonate ligand is synthesized to coordinate black phosphorus (BP) nanosheets. By virtue of Ru-P coordination, the lone pair electrons in BP are occupied, thus the RuL3@BP displays excellent stability in environment and different solvents. Subsequently, the resulting RuL3@BP is added into epoxy resin (EP) to fabricate EP nanocomposites. RuL3@BP can effectively enhance the dispersibility of BP in EP due to the surface coordination. When the RuL3@BP is added into epoxy in an amount of 3 wt%, the char yield is distinctly improved by 96.83%, which is ascribed to the cooperative catalytic charring effect between BP and RuL3. EP/RuL3@BP nanocomposites can easily pass the UL-94 V-0 rating, and its limiting oxygen index (LOI) value rises by 26.72%. The peak of heat release rate (PHRR) is decreased by 62.21% and the total heat release (THR) reduces by 35.22%, which is assigned to the restriction of heat transfer and inhibition of flammable gas by the dense char residues. The smoke production and diffusion of thermal pyrolysis gases are dramatically suppressed in the combustion. Meanwhile, owing to strong interfacial interactions between RuL3@BP and EP, EP nanocomposites filled with 3 wt% RuL3@BP exhibit a high thermal conductivity of 0.376 W m−1 K−1, which is enhanced by 52.23% and 65.64% compared with that of EP/BP composite (0.247 W m−1 K−1) and pure EP (0.227 W m−1 K−1), respectively. This surface coordination strategy provides a novel approach for fabricating advanced-performance nanocomposites.
Their pervasive use in industrial applications renders the development of environmentally benign flame-retardant epoxy (EP) thermosets a timely and important goal. The last two decades have witnessed ...the rise of phosphorus (P)-containing flame retardants for EP due to their high flame retardancy efficiency, low toxicity, multiple modes of action, molecular diversity and other favorable properties. P-containing flame retardants are classified into two types: reactive and additive, according to whether they participate in the curing process. Recent advances in both of these classes of P-containing flame retardants motivate this comprehensive review on the design and synthesis of P-containing flame retardants and their impact on the material properties of EP thermosets. This review focuses on the state-of-the-art knowledge of P-containing flame retardants and their effects on flame retardancy, thermal stability and mechanical properties of the resultant EP. First, representative flame-retardant mechanisms are reviewed. Subsequently, practical applications of P-containing flame-retardant EP thermosets are presented. Finally, the key challenges associated with P-containing flame retardants for EP thermosets are highlighted, and opportunities for future research in the field are proposed.
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•ZIF-8@Ti3C2Tx was synthesised and applied to prepare flame-retardant flexible polyurethane foam composites.•Flame-retardant flexible polyurethane foam composites displayed excellent ...heat and toxic gases suppression performance.•Flame-retardant flexible polyurethane foam composites showed notable mechanical properties during compression and tensile tests.•The flame-retardant mechanism of ZIF-8@Ti3C2Tx was systematically explored through gas and condensed products.
Flexible polyurethane foam (FPUF) is the most used polyurethane, but the highly flammable characteristic limits its widespread usage. In this work, ZIF-8@Ti3C2Txwas synthesized to reduce the heat and toxic gases of FPUF. Flame-retardant FPUF was characterized by cone calorimeter (Cone), thermogravimetric analysis/fourier-transform infrared spectroscopy (TG-FTIR), tensileand compression tests. Compared with pure FPUF, these results showed that the peak of heat release rate (PHRR), total heat release (THR), CO and HCN of FPUF6 decreased by 46%, 69%, 27% and 43.5%, respectively. Moreover, the tensile and compression strength of FPUF6 demonstrated a 52% and 130% increment, respectively. The superior dual metal catalytical charring-forming effect and physical barrier effect of ZIF-8@Ti3C2Tx were achieved. In summary, a simple and reliable strategy for preparing flame-retardant FPUF with reinforced mechanical and fire safety properties was provided.
•PTCO/POI-SiF presents better flame retardancy with an LOI of 31.2 %.•PTCO/POI-SiH and PTCO/POI-SiF have superhydrophobicity and great friction resistance.•UPF of PTCO/POI-SiH and PTCO/POI-SiF can ...reach 50+.•PTCO/POI-SiH and PTCO/POI-SiF have excellent antibacterial properties.
In this study, multifunctional polyester-cotton fabrics (PTCO) were constructed by gradually assembling polyethyleneimine phenyl phosphonate (POI) and different hydrophobic agents, respectively. The effect of different hydrophobic agents including tetraethyl orthosilicate, perfluorooctyltriethoxysilane (PFDTES), and hexadecyltrimethoxysilane on the thermal stability, flame retardancy, hydrophobic property, UV resistance and antibacterial property of PTCO/POI was investigated in detail. PTCO/POI-SiF had better flame retardancy due to the flame-retardant effect of PFDTES and POI, and the limiting oxygen index increased from 29.8 % to 31.2 %. The thermal oxidation stability of PTCO/POI-SiH and PTCO/POI-SiF was significantly improved in high temperatures, and the char residues at 700 °C were increased from 4.1 % to 7.6 % and 7.4 %. And PTCO/POI-SiH and PTCO/POI-SiF had excellent superhydrophobic properties with water contact angles of 151° and 162° and sliding angles of 4° and 3°. The ultraviolet protection factors of them were increased to 56.9 and 63.3, respectively, which had a good UV resistance. And both PTCO/POI-SiH and PTCO/POI-SiF had excellent antibacterial effects for E. coli and S. aureus. The breaking force, whiteness and moisture permeability of the finished fabrics had not been changed. Therefore, it is believed that PTCO/POI-SiH and PTCO/POI-SiF are promising for application in multifunctional fabrics.
The increasing demands for electronic packing materials necessitate stringent criteria for the overall properties of cyanate ester (CE) resins. In this work, a novel linear polyborosiloxane with a ...distinctive organic-inorganic hybrid Si–O–B backbone, featuring functional epoxy and phenyl groups (denoted as LPSi-B), was synthesized via a solvent- and catalyst-free one-pot polycondensation. Subsequently, the synthesized LPSi-B was co-crosslinked within the bisphenol A dicyanate ester (BADCy) thermoset network. The presence of abundant active epoxy groups in LPSi-B facilitated its involvement in the cyanate curing reaction, demonstrating excellent compatibility within the resin matrix. The resulting LPSi-B/BADCy composite not only exhibits outstanding mechanical properties but also demonstrates notable flame-retardant and dielectric characteristics. Specifically, the hybrid nature of LPSi-B, combining the flexibility of Si–O–B chains with the rigidity of side-chain phenyl groups, fosters intermolecular non-covalent π-π interactions directly linked to boron atoms, thus mitigating network polarization. Furthermore, the synergistic flame-retardant effect arising from boron and silicon components was harnessed to achieve halogen-free, phosphorus-free, and environmentally friendly fire safety outcomes. This innovative design ensures exceptional compatibility and interface bonding between LPSi-B and the polymer matrix, thereby endowing cyanate ester resin with superior comprehensive performance suitable for advanced applications in wave-transparent and electronic packing materials.
•A linear LPSi-B was synthesized for subsequent crosslinking with BADCy resin.•The mechanical strength of the LPSi-B/BADCy system was remarkably enhanced.•LPSi-B achieved halogen-free and environmental-friendly flame-retardant effect.•The dielectric and thermal performance was well-maintained for microwave applications.
Nanodiamonds are mysterious particles of carbon that have diverse properties that can be used for wide range of applications. In this study, we report a new pathway for in-situ synthesis of carbon ...nanostructures and their application for functionalization of poly(ethylene terephthalate) (PET) fabric. The carbon nanostructures were in-situ synthesized in atmospheric pressure dielectric plasma on the surface of the fabrics. The size, shape, and SAED pattern of particles were characterized by FESEM and HRTEM. The formation of carbon nanodiamonds and their chemical nature were also confirmed using Raman and FTIR spectroscopy. The modification resulted in significant improvement of flame retardant and hydrophilic properties of the treated samples. This approach offers a simple and rapid route for in-situ functionalization of textiles with nanodiamonds for various applications.
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•Quick and simple way to synthesize nanodiamonds (NDs) in-situ on PET fabrics.•Low temperature dielectric atmospheric pressure plasma was used.•Ethanol with Ar or N2 was used as a precursor.•Durable functionalities, such as hydrophilicity and flame-retardancy, were achieved.
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•Novel layered MXene-PPDA-6 was rationally designed and synthesized.•The addition of 1.0 wt% of MXene-PPDA-6 hybrid significantly increases both thermal stability and flame retardancy ...of PLA.•The MXene-PPDA-6 hybrid can improve the toughness of PLA.
The creation of thermostable, flame-retardant, mechanically robust bioplastics is highly desirable in the industry as one sustainable alternative to traditional petroleum-based plastics. Unfortunately, to date there lacks an effective strategy to endow commercial bioplastics, such as polylactide (PLA) with such desired integrated performances. Herein, we have demonstrated the fabrication of a novel MXene-phenyl phosphonic diaminohexane (MXene-PPDA) nanohybrid via the intercalation of PPDA into the MXene interlayer. The interlayer spacing of MXene nanosheets is enlarged and as-prepared MXene-PPDA is homogeneously dispersed in the PLA matrix. Incorporating 1.0 wt% MXene-PPDA enables PLA to achieve a UL-94 V-0 rating, with a ~22.2% reduction in peak heat release rate, indicating a significantly improved flame retardancy. Meanwhile, the 1.0 wt% MXene-PPDA also increases the initial decomposition temperature of PLA composite, giving rise to a ~25-fold enhancement in char yield relative to pure PLA. Additionally, the MXene-PPDA enhances the toughness while retains the mechanical strength for PLA. This work offers an innovative strategy for the design of multifunctional additives and the creation of high-performance polymers with high thermal stability, mechanical robustness and low flammability, expecting to find many practical applications in the industry.
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In order to meet the rapidly growing demand of multi-functional fabric, a super-hydrophobic flame retardant coating for cotton fabric with superior washability and abrasion resistance ...was prepared. Flame retardant finishing agent P, P-diphenyl-N-(3-(trithoxysilyl) propyl) phospinic amide (DPTES) and hydrophobic finishing agent polydimethylsiloxane @silicon dioxide (PDMS@SiO2) were fixed on the surface of cotton fabric by a simple sol–gel technology in combination with convenient brush-coating process. The coated cotton fabric was capable of self-extinguishing a flame, and the Limiting Oxygen Index (LOI) increased from 18.0% for the control cotton fabric to 26.0% for the treated one at weight gain of 30.3%. The water contact angle (WCA) of C3-PDMS-silica is around 154°, and the slip angle is 8°. In addition, the treated cotton fabric exhibits anti-washing and self-cleaning ability due to the superhydrophobic feature and superior friction resistance. The C3-PDMS-silica sample with excellent char-forming ability, as shown by thermogravimetric analysis (TGA), leading to outstanding flame retardancy. A composite char layer was constituted with char residues and ceramic layer during the combustion of inorganic silicon, which plays the role of heat insulation and flame retardant.
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•A high-efficiency multifunctional B-based polyphosphonamide (PB) was synthesized;•PB significantly enhanced flame retardancy and smoke suppression of epoxy resin;•PB simultaneously ...exhibited reinforcing and toughening effects towards epoxy resin;•PB maintained high thermal resistance and transparency of epoxy resin.
It is of great significance to develop high-performance epoxy resins (EPs) combining superior flame retardancy, smoke suppression, thermal oxidation stability, transparency and mechanical properties. However, current flame retardant design strategy usually realizes satisfied flame retardancy at the expense of other properties. Herein, a novel multifunctional high-efficiency boron-containing polyphosphonamide (PB) is synthesized, and its impacts on integrated properties of EP are studied thoroughly. As expected, the well-designed PB features high flame retardant efficiency due to the combination of phosphorus, boron and nitrogen elements, only 3 wt% of which increases the limiting oxygen index (LOI) and UL-94 classification of EP thermoset to 32.2% and V-0, with a ~32.2% decrease in the peak smoke production rate (PSPR). Compared with the unmodified EP sample, the tensile strength, elongation at break and impact strength of EP sample with 3 wt% PB are elevated by ~29.8%, ~37.7% and ~50.2%, respectively. Meanwhile, high glass transmission temperature and transparency are maintained. Hence, this work offers an integrated strategy to develop highly efficient multifunctional polyphosphonamides for the preparation of high-performance flame-retardant and smoke-suppressive EPs combining high mechanical strength and toughness, thermal resistance and transparency, which are expected to meet the increasingly rigorous industrial requirements.
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