The mechanical properties and fire resistance of vinyl ester resin (VER) composites containing cage‐shaped octaphenyl silsesquioxane (OPS), incompletely cage‐shaped phenyl silsesquioxane (PhT₇POSS), and ladder‐shaped phenyl silsesquioxane (PPSQ) were investigated. The POSS structure and dispersion have a great influence on the mechanical properties, thermal stability, and decomposition process of VER composites. The bending strength at break and modulus of the VER‐POSS composites were enhanced obviously, especially for VER‐PPSQ composite and VER‐OPS composite, respectively. In addition, PhT₇POSS‐based VER composites revealed the lower values of the peak heat release rate, total heat release, and total smoke release in cone calorimetry tests due to the formation of dense carbon/silica protective layers that acted as a barrier to heat and mass transfer. Moreover, the flame‐retardant mechanisms of condensed phase and gas phase were also investigated in detail. These results illustrate VERs modified by OPS, PhT₇POSS, and PPSQ are providing an applicable method to fabricate the composites with excellent flame‐retardant and mechanical properties.

中文翻译：

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不同苯基倍半硅氧烷改性的乙烯基酯树脂的机械和阻燃性能及热分解

研究了笼形八苯基倍半硅氧烷（OPS），不完全笼形苯基倍半硅氧烷（PhT ₇ POSS）和梯形苯基倍半硅氧烷（PPSQ）的乙烯基酯树脂（VER）复合材料的力学性能和耐火性。POSS的结构和分散度对VER复合材料的机械性能，热稳定性和分解过程有很大影响。VER-POSS复合材料的断裂抗折强度和模量明显提高，尤其是VER-PPSQ复合材料和VER-OPS复合材料。此外，PhT ₇基于POSS的VER复合材料在锥形量热测试中显示出较低的峰值放热速率，总放热和总烟气释放值较低，这是由于形成了致密的碳/二氧化硅保护层，从而阻碍了传热和传质。此外，还详细研究了冷凝相和气相的阻燃机理。这些结果说明，经OPS，PhT ₇ POSS和PPSQ改性的VERs为制备具有优异阻燃性和机械性能的复合材料提供了一种适用的方法。