Synergetic effect of thermal conductivity and flame retardancy of cyanate ester composites containing DOPO and BN with great dielectric properties

In this work, the exfoliated and functionalized boron nitride (f‐BN) nanosheets were prepared via facile treatment and used in the intumescent fire retardant (IFR) coatings, which offer passive fire protection to the steel. To acquire the best fire resistance, the formula of the coating was optimized using response surface methodology (RSM) based on central composite design. According to the result, the optimal sample, with 36.2 wt% ammonium polyphosphate (APP), 27.4 wt% pentaerythritol (PER), 16.8 wt% melamine (MEL), and 7.9 wt% f‐BN, was prepared and its fire resistance was tested in our lab. At the end of fire resistance test, the backside temperature of optimal sample was only 185.2°C, which was very close to the RSM‐predicted result, indicating satisfactory fire resistance. During the test, the coating decomposed to form an intumescent char layer with high graphitization degree and compactness, thus suppressing the transfer of heat and protecting the underlying steel. In addition, the optimal coating possessed great water tolerance and thermal stability, and its water contact angle and char yield reached up to 66.7° and 40.5%, respectively. Hence, this IFR coating with satisfied fire retardancy and water tolerance has broad practical future in the fire safety of steel structure.

Section: Introductionmentioning

confidence: 99%

Exfoliated and functionalized boron nitride nanosheets towards improved fire resistance and water tolerance of intumescent fire retardant coating

Wang

Huo

Shi

et al. 2020

“…On the other hand, high thermal conductivity of BN@APP quickly transfers heat away, reduces the temperature inside or on the surface of the PBS, thereby delaying the thermal degradation of the polymer. And T max of pure PBS appears at 419°C just similar as PBS composites, which suggests that the presence of BN@APP does not prominently change the degradation mechanism of PBS 40 . APP loaded on h‐BN has lower decomposition temperature, which produces acidic structure and catalyzes the carbonization of PBS.…”

Section: Resultsmentioning

confidence: 89%

“…And T max of pure PBS appears at 419 C just similar as PBS composites, which suggests that the presence of BN@APP does not prominently change the degradation mechanism of PBS. 40 APP loaded on h-BN has lower decomposition temperature, which produces acidic structure and catalyzes the carbonization of PBS. Due to the physical barrier of the catalytic carbonization effect and the flame-retardant functionalization BN@APP, the composites can produce more carbon residues from 3.17% of pure PBS to 5.59% of 1% BN@APP/ PBS.…”

Section: Thermal Stability Of the Bn@app/ Pbs Compositesmentioning

confidence: 99%

Highly flame‐retardant and low toxic polybutylene succinate composites with functionalized BN@APP exfoliated by ball milling

Jiang

Zhu

et al. 2022

This article describes the preparation of nitrogen‐phosphorus‐doped boron nitride (BN@APP) as a multifunctional nanofiller for flame‐retardant and thermal conductivity in polybutylene succinate (PBS). The BN@APP was obtained by a one‐step ball milling method. The improvement of thermal conductivity effectively reduces the generation of toxic smoke during PBS combustion. After incorporating 1.0 wt% BN@APP into the PBS, the thermal conductivity of the PBS composite is increased by 62.8%. The heat and toxic smoke are reduced significantly, the heat release rate, total heat release, and total smoke rate of PBS composites were dramatically reduced by 28.2%, 23.5%, and 44.8%, respectively, compared to pure PBS. This research offers a prospective route to prepare highly flame‐retardant composites that have low‐toxicity and smoke.

“…This phenomenon is also found in the T g investigation as shown in Figure 6a. The second weight loss between 450 and 750 C belonged to further degradation of LCER, 46 and the 30 wt% K-BN/LCER composites displayed higher residual char rates than others, indicating relatively better thermal stability. For the LCER without K-BN, there was residual, which can't be decomposed completely.…”

Section: Thermal Properties Of Lcer and K-bn/lcermentioning

confidence: 99%

Investigation of liquid crystal epoxy resin composites for application in cryogenic environments

Li,

Ma,

Liu

et al. 2024

It is well accepted that the intrinsic thermal conductivity is extremely important in achieving excellent thermal conductivity composite and can be improved via incorporation of mesogens. In this work, an azomethine type liquid crystal epoxy (LCE) with aliphatic ether was designed and synthesized with expected structure, and the liquid crystal epoxy resin (LCER), together with KH‐550‐modified boron nitride (K‐BN)/LCER composites, has been obtained. Results show an increase of 31.6% in the thermal conductivity of the matrix, which could result in an enhancement of 57.7% for the composites when compared with E‐51. Additionally, the coefficient of thermal expansion (CTE), dielectric properties, and shear strength of LCER and K‐BN/LCER composites were assessed across a broad temperature range. Remarkably, the 30 wt% K‐BN/LCER composites showed a maximum decrease of 37.8% in CTE, while maintaining adequate shear strength to fulfill the bonding requirement and high thermal conductivity at both RT and −196°C.