Supercritical foaming technology is used for producing foamed silicone rubber (SR) materials because of its many advantages, but this technology has been limited by its propensity to prepare microcellular silicone rubber foams (SRF) with surface defects. In this study, a novel method of preparing microcellular SRF without surface defects was successfully developed by investigating the principle of cellular formation during the process of supercritical foaming. Meanwhile, the microstructure, surface profile, mechanical properties, and thermal conductivity of microcellular SRF were investigated in detail. The results show that the plasticity of the SR matrix plays an important role in cellular formation. The maximum tensile strength of the microcellular SRF achieves 4.77 MPa and the elongation at break is 1866.29%. The thermal conductivity of the microcellular SRF achieves a minimum value of 0.14 W/m K, and the thermal insulation property is improved by approximately 39% compared with the SR composites. Based on the mechanism of cellular formation, the cellular formation and postcuring process were separated in this paper. First, the foamed sheets were rested at room temperature for 20 min. Then, the foamed sheets were fully vulcanized in a plate vulcanizing press at 165 °C for 8 min. A novel method of preparing microcellular silicone rubber foams without surface defects has been successfully created.

中文翻译：

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改善表面质量的微孔硅橡胶泡沫的微观结构和性能

超临界发泡技术因其众多优点而被用于生产发泡硅橡胶 (SR) 材料，但该技术因其制备具有表面缺陷的微孔硅橡胶泡沫 (SRF) 的倾向而受到限制。在这项研究中，通过研究超临界发泡过程中微孔形成的原理，成功开发了一种制备无表面缺陷的微孔 SRF 的新方法。同时，详细研究了微孔SRF的微观结构、表面轮廓、机械性能和热导率。结果表明，SR 基质的可塑性在细胞形成中起着重要作用。微孔SRF的最大拉伸强度达到4.77 MPa，断裂伸长率为1866.29%。微孔 SRF 的热导率达到最小值 0.14 W/m K，与 SR 复合材料相比，隔热性能提高了约 39%。本文根据细胞形成的机理，将细胞形成和后固化过程分开。首先，发泡片材在室温下静置 20 分钟。然后，将发泡片材在平板硫化机中在 165°C 下完全硫化 8 分钟。一种制备无表面缺陷的微孔硅橡胶泡沫的新方法已成功创建。本文将细胞形成和后固化过程分开。首先，发泡片材在室温下静置 20 分钟。然后，将发泡片材在平板硫化机中在 165°C 下完全硫化 8 分钟。一种制备无表面缺陷的微孔硅橡胶泡沫的新方法已成功创建。本文将细胞形成和后固化过程分开。首先，发泡片材在室温下静置 20 分钟。然后，将发泡片材在平板硫化机中在 165°C 下完全硫化 8 分钟。一种制备无表面缺陷的微孔硅橡胶泡沫的新方法已成功创建。