纳米二氧化硅改性聚丙烯酸高碳醇酯防蜡剂的制备及其防蜡机理研究

PREPARATION AND MECHANISM RESEARCH OF NANO-SILICA MODIFIED POLYACRYLIC HIGH ALCOHOL ESTER WAX INHIBITOR

利用纳米二氧化硅(SiO_(2))表面带有羟基特性,通过硅烷偶联剂γ-氨丙基三乙氧基硅烷(KH550)对其表面进行有机改性后,采用溶液聚合的方法接枝聚丙烯酸二十二酯(PDMA),得到有机-无机纳米复合粒子(SiO_(2)@PDMA)。利用红外分析、热重分析、扫描电镜等对其化学结构、接枝率和表观形貌进行表征,利用偏光显微镜和差示扫描量热仪(DSC)等考察改性原油蜡析出情况剂及蜡晶形貌尺寸变化。结果表明:纳米SiO_(2)表面成功接枝聚丙烯酸二十二酯,SiO_(2)@PDMA表面接枝率为46.0%,改性后纳米SiO_(2)粒径变大,分散性增强;将SiO_(2)@PDMA作为防蜡剂,在加剂量为1000 mg/kg时,可将乍得原油析蜡点降低4.7℃,蜡晶平均尺寸减小89.9%,防蜡率为63.5%,降黏率为79.9%。

Organic-inorganic nanocomposite particles(SiO_(2)@PDMA)were obtained by surface modification of nano-silica(SiO_(2))with the silane coupling agentγ-aminopropyltriethoxysilane(KH550),and following grafted with polydocosyl acrylate(PDMA)using solution polymerization method.Infrared spectroscopy,thermogravimetric analysis,and scanning electron microscopy were used to characterize its chemical structure,grafting rate and apparent morphology.The wax precipitation of modified crude oil and the change of wax crystal morphology and size were investigated using polarizing microscope and differential scanning calorimeter(DSC).The characterization results showed that the surface of nano-SiO_(2) was successfully grafted with polybehenyl acrylate,and the surface grafting rate of SiO_(2)@PDMA was 46.0%.After modification,the particle size of nano-SiO_(2) became larger and the dispersion was increased.Using SiO_(2)@PDMA as a wax inhibitor,a modification experiment was carried out on Chad crude oil.The results show that when the dosage is 1000 mg/kg,SiO_(2)@PDMA can reduce the wax precipitation point of Chad crude oil by 4.7℃,the average wax crystal size can be reduced by 89.9%.the wax prevention rate is 63.5%,and the viscosity reduction rate is 79.9%.