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以偶联剂γ-巯丙基三甲氧基硅烷(MPMS)对微米级硅胶微粒进行表面改性,制得表面键合巯基的改性微粒MPMS-SiO2.在非水溶剂二甲基甲酰胺(DMF)中使偶氮二异丁腈(AIBN)与MPMS-SiO2表面的巯基(-SH)构成表面引发体系(-SH/AIBN),实现甲基丙烯酸(MAA)在非水介质中的表面引发接枝聚合,制得接枝度为20 g/100 g的接枝微粒PMAA/SiO2,对其进行了表征,考察了主要因素对MAA表面引发接枝聚合的影响规律,研究了PMAA/SiO2对酚酸化合物阿魏酸的氢键吸附作用.结果表明,-SH/AIBN可顺利引发MAA在非水介质中的接枝聚合,适宜条件为75℃,AIBN用量为单体质量的1.5%.在PMAA/SiO2与阿魏酸分子之间可产生强氢键作用,包括高强度的多位点常规氢键与p型氢键,导致PMAA/SiO2对阿魏酸有强吸附力,吸附容量达266 mg/g.质子性溶剂甲醇中的溶剂竞争吸附作用使阿魏酸的吸附容量降低,升高温度吸附容量降低.
Surface modification of micron-sized silica particles with γ-mercaptopropyltrimethoxysilane (MPMS) as coupling agent to obtain surface-bonded mercapto-modified particles MPMS-SiO2 was carried out in a non-aqueous solvent dimethylformamide DMF) to make surface initiating system (-SH / AIBN) of azobisisobutyronitrile (AIBN) and thiol group (-SH) on the surface of MPMS-SiO2, to achieve the surface initiation of methacrylic acid (MAA) The grafting degree of grafted PMAA / SiO2 was 20 g / 100 g. The effects of main factors on the surface-initiated graft polymerization of MAA were investigated. The effects of PMAA / SiO2 on The results showed that -SH / AIBN could successfully initiate the graft polymerization of MAA in non-aqueous medium, the suitable conditions were 75 ℃, and the dosage of AIBN was 1.5% of the monomer mass. PMAA / SiO2 and ferulic acid molecules can produce strong hydrogen bonding, including high-intensity multi-site conventional hydrogen bonds and p-type hydrogen bonds, resulting in PMAA / SiO2 strong adsorption of ferulic acid, adsorption capacity of 266 mg / g. Solvent competitive adsorption in protic solvent methanol reduced the adsorption capacity of ferulic acid and decreased the adsorption capacity at elevated temperature.