Effect of dicumyl peroxide concentration on the polymerization kinetics of a polysilazane system

D׳Elia, Raffaele; Dusserre, Gilles; Confetto, Sylvie Del; Eberling-Fux, Nicolas; Descamps, Cédric; Cutard, Thierry

doi:10.1002/pen.24638

Cited by 20 publications

(15 citation statements)

References 40 publications

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“…These small protrusions may absorb external energy through obstructing and transferring the growth of cracks, making EP‐2 with better mechanical properties, which is consistent with the results of mechanical tests (shown in Figure and Table ). As for the fracture surfaces of EP/PVSZ (Figure d,h), some particles (marked in red circle) appear, which may be formed through the crosslinking reactions between reactive groups (such as vinyl groups) in PVSZ during curing process, indicating the poor compatibility of PVSZ in epoxy resin. In addition, fewer cracks on the fracture surface of EP/PVSZ are also the reasons for the poor mechanical properties of EP/PVSZ.…”

Section: Resultsmentioning

confidence: 99%

Simultaneously Improving the Thermal, Flame‐Retardant and Mechanical Properties of Epoxy Resins Modified by a Novel Multi‐Element Synergistic Flame Retardant

Chen

et al. 2019

Macro Materials & Eng

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are restricted because of the emission of toxic gases and corrosive smoke during combustion. [7][8][9][10] For decades, halogen-free flame retardants, particularly phosphoruscontaining ones have received more attention due to the satisfactory flame-retardant effect in gaseous and condensed phases simultaneously.Phosphorus-containing compounds are the most common halogen-free flame retardants, [11,12] which produce less toxic gases and smoke than halogen-containing compounds. [13,14] They also could impart excellent flame retardancy to EP, as reactive or additive flame retardants. [5] Compared with additive flame retardants, reactive flame retardants impart long-lasting flame retardancy and environmental resistance to EP. [6] Hence, preparation of a novel phosphorus-containing reactive flame retardant has become a hot research spot in recent years. [15] Huo et al. successfully synthesized a novel reactive flame retardant (DPT) through the reaction among DOPO, 1,4-phthalaldehyde, and triacetonediamine. Particularly, EP/DDM/ DPT-4 with 1.0 weight percent (wt%) phosphorus achieves limited oxygen index (LOI) value of 38.3% and UL-94 V-0 rating, while the glass transition temperature decreased by 11 °C. [15] Unfortunately, the traditional phosphorus-containing flame retardant can improve the flame retardant performance of epoxy resin, but its thermal and mechanical properties often decrease. [16,17] Therefore, it is necessary to find an approach to simultaneously improve the thermal, flame-retardant, and mechanical properties.In fact, multi-element synergistic flame retardants, such as P/N/F, [18] P/N/S/Mo, [19] and P/N/Si [20] have been proved to be an effective approach to overcome this predicament. Liu et al. developed a multi-element synergistic flame retardant system through the classical Kabachnik-Fields reaction, which achieved a combination of DOPO, POM, and POSS. The LOI value was 34.5% and the flexural strength increased by 11.7% when the content of POSS-bisDOPO was 20 wt%. [21] Reactive flame retardants containing different elements give EP with excellent flame retardancy and maintain high glass transition temperature. [5] Among the phosphorus-containing reagents, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) with high flame retardancy, good thermal stability, and high reactivity has been widely used in flame retardant modification of EP., [22,23] However, it will cause the bioaccumula tion of phosphorus and deterioration Flame-Retardant Epoxy ResinTo obtain epoxy resins with satisfactory thermal, flame retardant, and mechanical properties, a novel multi-element synergistic flame retardant (PPVSZ) is synthesized through the reaction between PH of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and CC of polysilazane (PVSZ) and utilized as a multi-element synergistic flame retardant for epoxy resins. The flame retardant mechanism is explored by XPS and SEM, confirming that the excellent flame-retardance efficiency owes itself to an optimal flame retardant way which jointly exerts the f...

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Section: Resultsmentioning

confidence: 99%

Simultaneously Improving the Thermal, Flame‐Retardant and Mechanical Properties of Epoxy Resins Modified by a Novel Multi‐Element Synergistic Flame Retardant

Chen

et al. 2019

Macro Materials & Eng

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“…Moreover, the ≡Si–H bond undergoes dehydrogenation reactions between two ≡Si–H bonds and/or between ≡Si–H and ≡Si–NH–Si≡ groups. Finally, the ≡Si–NH–Si≡ group can crosslink via transamination reaction [ 7 , 9 , 36 ].…”

Section: Methodsmentioning

confidence: 99%

“… Several crosslinking reactions of Durazane 1800 involve ≡Si-H, ≡Si–NH–Si≡, and RCH=CH2 groups that can occur in inert atmosphere [ 9 ]. …”

Section: Figurementioning

confidence: 99%

“…After processing, it is necessary to perform crosslinking followed by pyrolysis, leading to the desired ceramic. The crosslinking can be conducted thermally by adding a free radical initiator such as peroxides [ 9 , 10 , 11 ], catalysts [ 12 ], or photochemically [ 13 , 14 , 15 ], to form an infusible network. Another well-established method for the crosslinking of polysilazane and other PDCs is the thiol-ene click chemistry, which is also induced by means of UV light [ 16 , 17 , 18 ].…”

Section: Introductionmentioning

confidence: 99%

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Crosslinking Behavior of UV-Cured Polyorganosilazane as Polymer-Derived Ceramic Precursor in Ambient and Nitrogen Atmosphere

2021

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Polymer-derived ceramics (PDCs) based on silicon precursor represent an outstanding material for ceramic coatings thanks to their extraordinary versatile processibility. A promising example of a silicone precursor, polyorganosilazane (Durazane 1800), was studied concerning its crosslinking behavior by mixing it with three different photoinitiators, and curing it by two different UV-LED sources under both nitrogen and ambient atmosphere. The chemical conversion during polymerization and pyrolysis was monitored by FTIR spectroscopy. Pyrolysis was performed in a nitrogen atmosphere at 950 °C. The results demonstrate that polyorganosilazane can be cured by the energy-efficient UV-LED source at room temperature in nitrogen and ambient atmosphere. In nitrogen atmosphere, already common reactions for polysilazanes, including polyaddition of the vinyl group, dehydrogenation reactions, hydrosilylation, and transamination reaction, are responsible for crosslinking. Meanwhile, in ambient atmosphere, hydrolysis and polycondensation reactions occur next to the aforementioned reactions. In addition, the type of photoinitiator has an influence on the conversion of the reactive bonds and the chemical composition of the resulting ceramic. Furthermore, thermogravimetric analysis (TGA) was conducted in order to measure the ceramic yield of the cured samples as well as to study their decomposition. The ceramic yield was observed in the range of 72 to 78% depending on the composition and the curing atmosphere. The curing atmosphere significantly impacts the chemical composition of the resulting ceramics. Depending on the chosen atmosphere, either silicon carbonitride (SiCN) or a partially oxidized SiCN(O) can be produced.

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“…Otherwise, 3 wt% DCP, regarding the oligosilazane, was added to promote the cross‐linking of the modified precursors via hydrosilylation and polymerization reactions, thus increasing their ceramic yield upon pyrolysis. [ 37,65,66 ] For coating purposes, the procedure was set up in a way to obtain a final 20 wt% Yb‐modified polysilazane solution, which was stored inside the glovebox.…”

Section: Methodsmentioning

confidence: 99%

In Situ Generated β‐Yb₂Si₂O₇ Containing Coatings for Steel Protection in Extreme Combustion Environments

Leite

Viard

Galusek

et al. 2021

Adv Materials Inter

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The rapid permeation and degradation of silazane‐based coatings by water vapor limit their application in combustion environments. Hence, this work reports on the reaction of the oligosilazane Durazane 1800 with an appropriate Yb‐complex by a molecular approach and its application as protective thin coatings (1.2 µm) for AISI 304 in comparison with the benchmark Durazane 2250 in combustion‐like environments. Fourier transform infrared‐ and nuclear magnetic resonance‐spectroscopy elucidate the reaction mechanism and the chemical structure of the resulting Yb‐modified silazanes, whereas elemental and X‐ray diffractometry analyses confirm the formation of crystalline β‐Yb2Si2O7 and SiO2 after pyrolysis at 1000 °C in air. Energy dispersive spectroscopy and X‐ray photoelectron spectroscopy profile analyses show the enhanced diffusion of Fe, Cr, and Mn from the substrate into the Yb50 coating, which is responsible for a better adhesion (23.7 MPa), scratch tolerance (38 N), and a decreased coefficient of thermal expansion‐mismatch to the substrate, resisting 9 thermal cycles between 1000 and 20 °C. Despite the low Yb‐silicate content (6.8 wt%), only minor damage is caused to the Yb50 coating after wet oxidation in moist flowing air (1000 °C for 15 h), whereas the Durazane 2250 coating spalled‐off. This is a clear indication of the potential of the Yb2Si2O7‐containing coatings to protect metals and ceramics in extreme combustion environments.

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Effect of dicumyl peroxide concentration on the polymerization kinetics of a polysilazane system

Cited by 20 publications

References 40 publications

Simultaneously Improving the Thermal, Flame‐Retardant and Mechanical Properties of Epoxy Resins Modified by a Novel Multi‐Element Synergistic Flame Retardant

Simultaneously Improving the Thermal, Flame‐Retardant and Mechanical Properties of Epoxy Resins Modified by a Novel Multi‐Element Synergistic Flame Retardant

Crosslinking Behavior of UV-Cured Polyorganosilazane as Polymer-Derived Ceramic Precursor in Ambient and Nitrogen Atmosphere

In Situ Generated β‐Yb₂Si₂O₇ Containing Coatings for Steel Protection in Extreme Combustion Environments

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Effect of dicumyl peroxide concentration on the polymerization kinetics of a polysilazane system

Cited by 20 publications

References 40 publications

Simultaneously Improving the Thermal, Flame‐Retardant and Mechanical Properties of Epoxy Resins Modified by a Novel Multi‐Element Synergistic Flame Retardant

Simultaneously Improving the Thermal, Flame‐Retardant and Mechanical Properties of Epoxy Resins Modified by a Novel Multi‐Element Synergistic Flame Retardant

Crosslinking Behavior of UV-Cured Polyorganosilazane as Polymer-Derived Ceramic Precursor in Ambient and Nitrogen Atmosphere

In Situ Generated β‐Yb2Si2O7 Containing Coatings for Steel Protection in Extreme Combustion Environments

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Product

Resources

About

In Situ Generated β‐Yb₂Si₂O₇ Containing Coatings for Steel Protection in Extreme Combustion Environments