Flame‐retardant materials based on phosphorus‐containing polyhedral oligomeric silsesquioxane and bismaleimide/diallylbisphenol a with improved thermal resistance and dielectric properties

Abstract

Polyhedral oligomeric silsesquioxane containing 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DP) was used to flame-retard 4,4 0 -bismaleimidophenyl methane (BDM)/2,2 0 -dially bisphenol A (DBA) resins, and the integrated properties of the resins were investigated. The fire resistance of BDM/DBA resins containing DP was analyzed by limiting oxygen index (LOI) and vertical burning (UL94) tests. The results show that DP increased the LOI of the resins from 25.3 to 38.5%. The BDM/DBA resins were evaluated to have a UL-94 V-1 rating, which did not satisfy the high standards of industry. On the other hand, BDM/DBA containing DP achieved a UL-94 V-0 rating. The thermal stability and char formation were studied by thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy. TGA and scanning electron microscopy-energy-dispersive X-ray spectrometry measurements demonstrated that the DP resulted in an increase in the char yield and the formation of the thermally stable carbonaceous char. The results of Raman spectroscopy showed that the DP enhanced the graphitization degree of the resin during combustion. Moreover, the modified BDM/DBA resins exhibited improved dielectric properties. Specifically, the dielectric constant and loss at 1 MHz of the BDM/DBA/15% DP resin were 3.11 and 0.008, respectively, only about 93 and 73% of those of the BDM/DBA resin. All of the investigations showed that DP was an effective additive for developing high-performance resins with attractive flame-retardant and dielectric properties.

Synthesis of low phosphorus flame retardant containing benzimidazole and hydroxyl and its application in reducing combustion smoke for epoxy resin

“…Although this effect reduced the initial decomposition temperature of the flame‐retardant EP system, the char residual content of the system at 750°C was higher than that of pure EP. It can be seen from Table 2 that although the thermal stability of the modified EP was decreased, the decrease was still smaller than that of some other P and N‐containing flame retardants reported in the literature 37,38 . Additional, the glass transition temperature ( T g ) of EP and EP/6% DOPO‐BHM was characterized by DSC tests.…”

“…It can be seen from Table 2 that although the thermal stability of the modified EP was 31 P NMR (B), and 1 H NMR (C) spectra of DOPO-BHM F I G U R E 3 TG curves of epoxy thermosets under nitrogen atmosphere decreased, the decrease was still smaller than that of some other P and N-containing flame retardants reported in the literature. 37,38 Additional, the glass transition temperature (T g ) of EP and EP/6% DOPO-BHM was characterized by DSC tests. In Figure 3C…”

The Recent Advances of Polymer–POSS Nanocomposites With Low Dielectric Constant

“…However, for unmodified BMI resin, the disadvantages such as high molding temperature and brittle curing hinder its application in the highend direction. [120][121][122] The presence of flexible long straight chains will enhance the solubility of the polymer and improve the processing performance of the polymer. Devaraju et al [123] prepared POSS-AEBMI nanocomposites with high thermal stability, limiting oxygen index, and low dielectric constant by reacting four different linear aliphatic ether-linked aromatic bis maleimides (AEBMI) with different mass fractions of OAPs.…”

“…However, for unmodified BMI resin, the disadvantages such as high molding temperature and brittle curing hinder its application in the high‐end direction. [ 120–122 ] The presence of flexible long straight chains will enhance the solubility of the polymer and improve the processing performance of the polymer. Devaraju et al.…”

Flame-Retardant Performance of Transparent and Tensile-Strength-Enhanced Epoxy Resins

“…Both of the two spectra displayed two peaks at 1355 cm −1 (D band) and 1582 cm −1 (G band). Generally, the D band corresponds to carbons in a disorder arrangement, while the G band relates to carbons in graphite layers [9,36,37]. The intensity of D and G bands was represented by the relevant peak area, and the ratio of the intensity of D and G bands (I D /I G ) of neat EP and EP-DSD9 thermosets was calculated by the ratio of peat areas.…”