| 摘要 |
Reinforcing cold-curing silicone rubber with pptd. SiO2 having a high surface area and sp. vol. and low Na content gives products with good thermal and mech. propertise, Thus, silicone rubber vulcanizates filled with 40phr pptd. SiO2(furface area 242m2/g, sp. vol. 4.8mL/g, residual Na content 425ppm, 45μparticles(0.05%, moisture content(105o) 5.90%, wt. loss at 1200o 9.22%) have tensile strength 76kg/cm2, elongation 430%, 100% modulus 19.8kg/cm2, Shore A hardness 61, tear strength 18kg/cm, Zwick resilence 39%, and compression set (70h, 150o) 78% before, and 73,302,30,74,14,46 and 21 resp. after 16h at 200o, compared with 76,449,14.5,55,15,42 and 75. resp., before aging and 80,316,22.5,69,15,48, and 23, resp., after aging when filled with Cab-O-Sil SiO2.
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