以水玻璃和硫酸为原料,采用超重力反应沉淀法合成了超细二氧化硅粉体。研究表明:与传统搅拌槽反应器相比,在超重力反应器内,二氧化硅沉淀反应的时间可大大缩短(缩短至10 m in以内);通过产品分析测试发现,所得到的二氧化硅产品具有粒径小...以水玻璃和硫酸为原料,采用超重力反应沉淀法合成了超细二氧化硅粉体。研究表明:与传统搅拌槽反应器相比,在超重力反应器内,二氧化硅沉淀反应的时间可大大缩短(缩短至10 m in以内);通过产品分析测试发现,所得到的二氧化硅产品具有粒径小(<20 nm)、粒度均匀、比表面积大、孔径分布较窄等特点,并具备能提高与高分子材料的相互作用的中大孔结构。展开更多
在催化剂存在下,二羟甲基丙酸(DMPA)为反应单体,可成功地接枝超支化聚酯到经硅烷偶联剂γ-氨丙基三乙氧基硅烷(KH-550)处理过的超细二氧化硅表面。通过IR、TG、氨基分析、亲水性测试等表征其性能。结果表明,每1.5 g二氧化硅和0.65 g KH-...在催化剂存在下,二羟甲基丙酸(DMPA)为反应单体,可成功地接枝超支化聚酯到经硅烷偶联剂γ-氨丙基三乙氧基硅烷(KH-550)处理过的超细二氧化硅表面。通过IR、TG、氨基分析、亲水性测试等表征其性能。结果表明,每1.5 g二氧化硅和0.65 g KH-550反应表面氨基含量最多,为7.986 mmol/g;每1.00 g KH-550改性二氧化硅和3.00 g DMPA反应产物接枝率最高,为85.55%,产物亲油疏水性最好,使液体石蜡黏度改变最小。不同代超支化聚酯改性二氧化硅固化环氧树脂,漆膜性能表明,4.00 g DMPA改性二氧化硅固化环氧树脂漆膜铅笔硬度和柔韧性增加,改性效果最优。展开更多
Dynamic rheological properties of poly(methyl vinyl)siloxane(PMVS) filled with ultratra silica (SiO 2) were analyzed on an advanced rheometric expansion system(ARES) at 25 ℃ by varying the strain (γ) and the frequen...Dynamic rheological properties of poly(methyl vinyl)siloxane(PMVS) filled with ultratra silica (SiO 2) were analyzed on an advanced rheometric expansion system(ARES) at 25 ℃ by varying the strain (γ) and the frequency (ω). The results show that an incorporation of 5% SiO 2 into PMVS at 25 ℃ could be enough to impact a significant increase on the storage modulus (G′) of the uncured system, which is believed to be caused by the strong interactions among silica fillers. Meanwhile, γ dependence of G′ related to Payne effect was observed upon increasing γ amplitude, and no distinct “second plateau” was observed even the content of SiO 2 approached 20%. We owe this phenomenon partly to the surface esterification of silanols and partly to the unvulcanized PMVS.展开更多
文摘以水玻璃和硫酸为原料,采用超重力反应沉淀法合成了超细二氧化硅粉体。研究表明:与传统搅拌槽反应器相比,在超重力反应器内,二氧化硅沉淀反应的时间可大大缩短(缩短至10 m in以内);通过产品分析测试发现,所得到的二氧化硅产品具有粒径小(<20 nm)、粒度均匀、比表面积大、孔径分布较窄等特点,并具备能提高与高分子材料的相互作用的中大孔结构。
文摘在催化剂存在下,二羟甲基丙酸(DMPA)为反应单体,可成功地接枝超支化聚酯到经硅烷偶联剂γ-氨丙基三乙氧基硅烷(KH-550)处理过的超细二氧化硅表面。通过IR、TG、氨基分析、亲水性测试等表征其性能。结果表明,每1.5 g二氧化硅和0.65 g KH-550反应表面氨基含量最多,为7.986 mmol/g;每1.00 g KH-550改性二氧化硅和3.00 g DMPA反应产物接枝率最高,为85.55%,产物亲油疏水性最好,使液体石蜡黏度改变最小。不同代超支化聚酯改性二氧化硅固化环氧树脂,漆膜性能表明,4.00 g DMPA改性二氧化硅固化环氧树脂漆膜铅笔硬度和柔韧性增加,改性效果最优。
文摘Dynamic rheological properties of poly(methyl vinyl)siloxane(PMVS) filled with ultratra silica (SiO 2) were analyzed on an advanced rheometric expansion system(ARES) at 25 ℃ by varying the strain (γ) and the frequency (ω). The results show that an incorporation of 5% SiO 2 into PMVS at 25 ℃ could be enough to impact a significant increase on the storage modulus (G′) of the uncured system, which is believed to be caused by the strong interactions among silica fillers. Meanwhile, γ dependence of G′ related to Payne effect was observed upon increasing γ amplitude, and no distinct “second plateau” was observed even the content of SiO 2 approached 20%. We owe this phenomenon partly to the surface esterification of silanols and partly to the unvulcanized PMVS.
