Page 53 - 《橡塑技术与装备》英文版2025年12月

MATERIALS AND FORMULATIONS

relatively uniform cell size, with an average diameter of around physical foaming aids can produce medium-foaming foam
100 μm. The silicone rubber with sodium bicarbonate showed materials.
poorer uniformity in cell size, with some cells reaching up to (2) During the foaming molding process, pressure affects
1.6 mm in diameter and large inter-cell spacing, indicating the foaming effect. The lower the pressure, the better the
poor dispersion of the foaming aid in the polymer. The silicone foaming effect, and the greater the foaming ratio.
rubber with hollow glass microspheres had the smallest cells, (3) When using the aforementioned three foaming aids
with diameters ranging from 40 to 65 μm. to foam liquid silicone rubber, the change trends of the tensile
strength and elongation of the foamed silicone rubber are the
same, and their change trends are also the same as the change
trend of density, that is, the lower the density of the foamed
silicone rubber, the lower the tensile strength and elongation.
Figure 6 Electron microscope photographs of W 6 , T 3 ,
and B 3 samples (4) When using the aforementioned three foaming aids
to foam liquid silicone rubber, the amount of physical foaming
3 Conclusion agent added is smaller, and the pore size of the foamed silicone
(1) When using addition-type liquid silicone rubber as rubber is more uniform. By adding 2% physical foaming aid
the matrix for foaming, the foaming effect of using physical and curing under non-pressurized conditions, a foamed silicone
3
foaming aids is superior to that of using sodium bicarbonate rubber with a density of 0.4 g/cm , a tensile strength of 0.7 MPa,
and hollow glass microspheres as foaming aids. Using sodium and an average pore size of approximately 100 μm can be
bicarbonate and hollow glass microspheres as foaming aids obtained.
can only produce low-foaming foam materials, while using

Vol.51，2025 ·47·