Page 52 - 《橡塑技术与装备》英文版2025年12月

HINA R&P TECHNOLOGY AND EQUIPMENT

Figure 4 Relationship between the tensile strength of foamed silicone rubber filled with different foaming agents and
the mass fraction (a) and density (b) of the foaming agent

Figure 5 Relationship between elongation rate and mass fraction (a) and density (b) of foaming agent in foamed
silicone rubber with different foaming agents added

surface-modified fumed silica and other additives to prepare and hollow glass microspheres is shown in Figure 5. As the
foamed silicone rubber with a tensile strength of 0.697 MPa filling amount increases, the elongation rate decreases; as the
and an apparent density of 0.553 g/cm3. Compared to this, density of the foamed silicone increases, the elongation rate
the foamed silicone rubber with 2% physical foaming agent increases. When adding physical foaming aids, the elongation
has a higher tensile strength and lower density. When using rate changes more significantly with changes in the filling ratio,
sodium bicarbonate for foaming, the tensile strength and and the trend of elongation rate change is the same as the trend
elongation of foamed silicone rubber with 3% and 2% sodium of density change.
bicarbonate added show little change. When using hollow glass 2.3 Morphology of foamed silicone rubber
microspheres, the tensile strength and elongation of foamed Based on the relationship between the dosage of three
silicone rubber decrease slowly with increasing addition level. foaming aids and their foaming effects, silicone rubber samples
Among these three foaming agents, to obtain foamed silicone were prepared with the following proportions of foaming
rubber with the same tensile strength, the amount of physical aids: 4% physical foaming agent (labeled as W6), 3% sodium
foaming agent required is smaller. bicarbonate (labeled as T3), and 8% hollow glass microspheres
2.2.2 Elongation (labeled as B3). The cell structure of these samples was

The elongation rate of foamed silicone obtained using observed using an electron microscope, as shown in Figure 6.
physical foaming aids, sodium bicarbonate as a foaming aid, The silicone rubber with the physical foaming agent exhibited

·46· Vol.51，No.12