Flame retardant and mechanism of vinyl ester resin modified by octaphenyl polyhedral oligomeric silsesquioxane

Abstract

Flamability is one of the major issues for utilization of bisphenol A-type vinyl ester resin (VER) polymeric composites in practical applications. The thermal stability and mechanical property of VER composites containing octaphenyl polyhedral oligomeric silsesquioxane (OPS) were investigated and discussed in detail. With increasing the mass ratio of OPS, the residues yield at 800°C and bending strength at break of the VER/OPS composites were enhanced, accompanied with the gradually decreased values of the peak heat release rate, total heat release, and total smoke release due to the formation of dense carbon/silica protective layers that acted as a barrier to heat and mass transfer. In addition, the flame-retardant mechanisms of condensed phase and gas phase were analyzed by XPS, TGA-FTIR, and GC-MS. The results showed that when OPS was incorporated to the resin matrix, the characteristic peaks intensity of the gaseous products was reduced obviously due to some of the characteristic groups still retained in condensed phase. Therefore, the significance of this work is providing an optional method to fabricate flame-retarding VER composites with excellent mechanical properties.

Improved mechanical and flame resistance properties of vinyl ester resin composites by lithium containing polyhedral oligomeric phenyl silsesquioxane

“…The main pyrolysis product peaks of pure VER and VER‐3 are similar, including phenol derivatives/water (3586 cm −1 ), aliphatic components (2660–2860 cm −1 ), aromatic components (3010, 1504, and 670 cm −1 ), carbonyl components (1723 cm −1 ), ester/ether components (1153 cm −1 ), and CO (2178 cm −1 ). [ 31,32 ] With 3 wt% Li‐Ph‐POSS incorporation of the matrix, the pyrolysis product peaks have declined except for 3010, 1504 — , and 670 cm −1 . The reduction demonstrates that more decomposition products of the matrix remain in the condensed phase.…”

“…The Si 2p spectra (Figure 8D) reveal two silicon configurations, which are SiOSi/SiOC at 103.4 eV and CSi at 102.0 eV. [ 26,28,32,33 ] The Li 1s spectra (Figure 8E) are only one peak attributed to LiCO 3 . It is reported that LiCO 3 can promote the formation of char layer.…”

“…The detailed chemical structure information of char residues of VER and VER-3 composite after test is analyzed by XPS. As shown in Figure 8A, there are two peaks [26,28,32,33] The Li 1s spectra (Figure 8E) are only one peak attributed to LiCO 3 . It is reported that LiCO 3 can promote the formation of char layer.…”

Enhanced mechanical and flame retardancy properties of vinyl ester resin systems with the synthesis of two flame retardants with vinyl group

“…The major pyrolysis gases detected in the decomposition process of VER systems are phenol derivatives/water (3650 cm −1 ), aromatic components (3072, 3033, 1603, 1506, 1335 cm −1 ), aliphatic components (2973, 2930 cm −1 ), ester or ether components (1752, 1256, 1176, 1126 cm −1 ) and CO 2 (2358 cm −1 ), which correspond well with the decomposition of VER matrix in the literature. 38 As shown in Fig. 10(A), the gas species changed when the flame retardants were added into VER.…”

Study on the evaluation and compensating strategy for the wear damage of non‐return valve during injection molding process

“…[5][6][7] Nonetheless, some potential disturbances may occur and have an influence on the stabilization of the part weight. [8] Therefore, some researchers have adopted data analysis to achieve failure detection and maintenance prediction of injection molding machine. Pilla et al [9] use edge computing and cloud computing for machine learning by introducing the Industry 4.0 framework, to enable effective prediction and management of maintenance operations for injection molding equipment.…”