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This study used the sol–gel method to synthesize a non-halogenated, hyperbranched flame retardant containing nitrogen, phosphorus, and silicon (HBNPSi), which was then added to a polyurethane (PU) matrix to form an organic–inorganic hybrid material. Using 29Si nuclear magnetic resonance, energy-dispersive X-ray spectroscopy of P- and Si-mapping, sc...
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... flame retardance of polymeric material is classified into the V-0, V-1, and V-2 levels. Figure 3 and Table 2 reveal that the pristine PU failed and did not achieve any level. Dripping was observed, and the drips ignited the cotton below. ...Similar publications
Emerging nanoadsorbent materials could be promising tools for the treatment of numerous water contaminants, including heavy metal ions, dyes, bacteria, and fungi, due to their unique characteristics such as size, shape, surface modification, and specific surface area. The smaller size of the materials with larger surface area and more active sites...
An innovative hybrid thermoplastic manufacturing process has been investigated, which consists in carbon fibres reinforced poly(ether-ether-ketone) (PEEK) prepreg sandwiched between two amorphous polyetherimide (PEI) films. By using a laser-assisted automated fibre placement (AFP), a laminate is produced by the deposition of hybrid prepreg tapes, l...
As an organic–inorganic hybrid material, metal organic frameworks (MOFs) has a great development prospect in the field of photocatalysis. Herein, the in situ growth of Bi-based MOF (CAU-17) on Bi2WO6 was utilized to obtain Bi2WO6/CAU-17 photocatalyst by a simple solvothermal transformation method. Bi2WO6 can be used both as template and Bi source....
The structure and properties of organic–inorganic hybrid perovskites are impacted by the order–disorder transition, whose driving forces from the organic cation and the inorganic framework cannot easily be disentangled. Herein, we report the design, synthesis and properties of a cage-in-framework perovskite AthMn(N 3 ) 3 , where Ath ⁺ is an organic...
Chirality has become an important research subject. The research areas associated with chirality are under substantial development. Meanwhile, graphene is a rapidly growing star material and has hard‐wired into diverse disciplines. Rational combination of graphene and chirality undoubtedly creates unprecedented functional materials and may also lea...
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... However, due to the excellent stability of polyurethane, the material is not easily degraded by microorganisms or air under natural conditions; it is insoluble, and it is difficult to treat [5][6][7][8][9]. Moreover, more and more states explicitly prohibit its burial or incineration, and it is difficult to recycle, resulting in a waste of living space and chemical resources [1,4,[10][11][12][13][14]. Therefore, how to deal with the degradation and reuse of waste PU in a green and efficient manner is crucial to determine [15][16][17][18]. The recycling prospect of waste polyurethane is very broad and has great potential research value and significance. ...
Polyurethane (PU) has become one of the most widely used materials in the industrial field due to its excellent performance and wide range of applications. The increasing consumption of polyurethane materials has resulted in significant polyurethane waste. We can recycle waste polyurethane to obtain recycled polyurethane, but to make the recycled polyurethane meet different performance requirements in terms of utility and cost and enable the recycled polyether polyol to be further applied to high-end applications, it is necessary to improve the use value of recycled polyether polyol. In this paper, self-made Fluorodiol was added to the degradation process of waste polyurethane to obtain fluorinated regenerated polyether polyol. Recycled fluorinated polyurethane with excellent performance was prepared using fluorine-containing recycled polyether polyol. The regenerated fluorinated polyether polyols were characterized by infrared spectroscopy, viscosity, hydroxyl value, and GPC molecular weight distribution. The density, apparent morphology, water absorption, mechanical strength, thermal conductivity, and thermal stability of RFPU rigid foams with different fluorine contents were studied by scanning electron microscopy. The results show that when the addition of Fluorodiol was 8% of the mass of waste polyurethane, the density was 41.2 kg/m3, the immersion loss rate was 2.125%, the compressive strength was 0.315 Mpa, and the thermal conductivity was 0.0227 W/m·K. The RFPU prepared by Fluorodiol has low surface energy, good compressive strength, hydrolysis resistance, and is expected to be widely used in special insulation materials. Thus, the sustainable recycling of polyurethane is achieved.
... The same phosphaphenanthrene derivative (DOPO-HQ) was adopted by Shen et al. [27], who synthesized a hyperbranched organic-inorganic hybrid material containing Si, N and P, aimed at improving the flame retardancy of a polyolbased polyurethane. The sol-gel procedure employed DOPO-HQ and 3-isocyanatopropyltriethoxysilane (IPTS) through two polycondensation steps, the second following the addition of triglycidyl isocyanurate (TGIC). ...
The ease of flammability of polymers represents a key issue that limits their applications in different advanced sectors. In this context, a reliable and effective solution regards the use of flame retardants, i.e., additives that are able to slow down (or even stop) the flame propagation and to enhance the resistance to an irradiative heat flux. Among the different flame retardants designed, synthesized, and applied up-to-now, the utilization of inorganic particles, inorganic and hybrid organic-inorganic coatings has gathered a great interest from either the academic and industrial community, as these structures can provide remarkable flame retardant features to different polymer systems, in which they are embedded or applied onto. In particular, the in situ generation (through sol-gel processes, i.e. hydrolysis and condensation reactions from tailored alkoxide precursors) of ceramic phases, either in the form of particles or as surface coatings, has clearly demonstrated its effectiveness in creating a physical barrier that limits the degradation of the polymer when subjected to the application of a flame or an irradiative heat flux. It also lowers the heat and mass transfer from the degrading polymer to the surroundings and vice versa, hence providing an overall enhancement of heat and fire resistance. This review work seeks to provide an up-to-date overview of the most recent advances in the use of sol-gel methods for conferring flame retardant features to bulk polymers, cellulosic textiles (cotton), and polymer foams. In addition, the current limitations and the potential progresses of these approaches are discussed.Graphical abstract
... Therefore, it is of great significance to study the flame retardant performance of polyurethane enhanced by flame retardants. The common method is to introduce additive flame retardants and reactive flame retardants into polyurethane to improve its flame retardancy (Jia et al., 2019;Li et al., 2020;Shen et al., 2021;Çalışkan et al., 2021). ...
Phosphomolybdic acid (PMA) as a synergist was added into polyurethane (PU) rigid foam with ammonium polyphosphate (APP) to improve its flame retardancy and thermal stability. The combustion performance of PU was studied by limiting oxygen index (LOI), UL-94, and a cone calorimeter. The thermal degradation behavior of PU was determined by thermogravimetric analysis (TG) and thermogravimetric infrared spectroscopy (TG-IR). Experimental results showed that the introduction of PMA could further improve the flame retardant performance of PU/APP composites and significantly increase the amount of carbon residue at high temperatures. Adding 3wt% PMA to PU containing 12wt% APP could make the foam pass UL-94 V-0, increase the carbon residue at 800°C by 69.16% in the air atmosphere, and decrease the THR by 24.62% compared to those of PU/15APP. TG-IR results showed that the presence of PMA reduced the production of small-molecule gas-phase products. As for the mechanical properties of PU composites, the addition of PMA influences their density and compressive strength obviously. The results suggest that PMA and APP have good synergistic flame retardancy on PU and can reduce its fire risk.
... The following article by Shen et al. [4] contributes to the conversation regarding an eco-friendly polyurethane hyperbranched hybrid made through the sol-gel process. The organic-inorganic hybrid material was created by introducing a non-halogenated, hyperbranched flame retardant containing nitrogen, phosphorus, and silicon to a polyurethane (PU) matrix. ...
Sustainability is a central value in the United Nations’ 17 sustainable development goals (SDGs), which include no poverty, zero hunger, good health and well-being, quality education, gender equality, clean water and sanitation, affordable and clean energy, decent work and economic growth, industry innovation and infrastructure, reduced inequalities, sustainable cities and communities, responsible consumption and production, climate action, life below water, and life on land [...]
As a component of printed circuit substrate, copper clad laminate (CCL) needs to meet the performance requirements of heat resistance, flame retardancy, and low coefficient of thermal expansion (CTE), which, respectively, affects the stability, safety, and processability of terminal electronic products. In this paper, benzocyclobutylene (BCB)-functionalized phosphorus-oxygen flame retardant composites were prepared through introducing the BCB groups, and the performance was researched by thermogravimetric analysis, microcombustion calorimetry, and thermomechanical analysis. The research results show that these phosphorus oxide compounds containing BCB groups show good thermal stability and low total heat release (THR) after thermal curing, and the more BCB groups on the phosphorus oxide monomers, the better the thermal stability and flame retardancy of cured resins. The Td5 and THR of the composite (M3) are as high as 443 °C and 23.1 kJ/g, respectively. In addition, the CTE of M3 is as low as 16.71 ppm/°C. Introduction of BCB groups which can be crosslinked through heat to improve the thermal stability, flame retardancy, and reduced CTE of traditional organophosphorus flame retardant materials. These materials are expected to be good candidates for CCL substrates for electronic circuits.
A new phosphorylated cyclotriphosphazene hyperbranched polymer (HBPDP) was prepared by a nucleophilic substitution reaction of diphenyl chlorophosphate (DPCP) with a cyclotriphosphazene hyperbranched polyester (HBP) and introduced into epoxy resin (EP) materials. The introduction of HBPDP can improve the tensile strength and toughness of EP materials. Among them, the strength and toughness of 1% HBPDP/EP composites reached the best with 82.74 Mpa and 408.50 J/m³, respectively. As the loading of HBPDP increased, the strength and toughness of HBPDP/EP composites decreased. Furthermore, the inclusion of HBPDP accelerated EP material degradation and increased the residue. More crucially, introducing HBPDP to EP materials can lower the amount of heat, smoke, and harmful gases released during burning, as well as enhance the flame retardancy and smoke suppression properties of the materials. The results showed that when 5 wt% HBPDP was added, the LOI value of EP composites reached 29.7%, which passed the UL-94 V-0 rating test. Meanwhile, compared with pure EP, the THR, TSP and smoke CO content of 5% HBPDP/EP composites were reduced by 27.3%, 20.3% and 60.7%, respectively, generating more and denser residual carbon layers.
The chapter is devoted to a selective presentation of the techniques and methods that bring benefits in the field of fire-retarded materials. It is mainly focused on the characterization of chars and residues upon fire. It includes spectroscopic techniques (chemical composition of the residues), optical and electronic microscopy (morphology of the residues), and rheology (dynamics of char/residue formation).
Dendritic polymers (dendrimers and hyperbranched polymers) are becoming increasingly popular due to their vast range of uses. Due to their distinctive and novel qualities, they have demonstrated a strong interest. Since its discovery, dendritic polymers have become a potential material for many research applications, ranging from biomedical and tissue engineering to catalytic and energy applications. Since then, dendritic polymers' unique features have become a promising platform for a variety of uses. Dendritic polymers have made great progress in overcoming basic and technological problems related to their biomedical and energy applications. This review summarizes the strategies of synthesizing dendrimers and hyperbranched polymers. Further, the review highlights the applications of dendrimers and hyperbranched polymers in many study fields such as drug delivery, gene delivery, tissue engineering, catalysis, and energy storage. This review concludes with future avenues to be explored for the applications of dendritic polymers.
