In this work, three multi-alkyl polyamines, i.e., pentahexadecyl diethylenetriamine (PHDETA), hexahexadecyl triethylenetetramine (HHTETA) and heptahexadecyl tetraethylenepentylamine (HHTEPA), were synthesized and evaluated as pure flow improvers for crude oil. Under certain conditions, PHDETA, HHTETA and HHTEPA were able to improve the flow properties of L401 crude oil samples by reducing the viscosity of the crude oil by 97.5%, 94.3% and 97.1%, respectively. The three synthesized alkyl polyamines PHDETA, HHTETA and HHTEPA were able to reduce the viscosity of L1316 crude oil to a maximum of 94.3%, 93.7% and 94.9%, respectively. The pour point of L401 crude oil could be greatly reduced by 3.1 °C, 3.3 °C and 3.4 °C with PHDETA, HHTETA and HHTEPA, respectively. The pour point of L1316 crude oil with PHDETA, HHTETA and HHTEPA was strongly decreased by 2.8 °C, 2.9 °C and 3.2 °C, respectively. Photomicrographs showed the co-crystallization of L401 and L1316 crude oil in the presence of PHDETA, resulting in the formation of a non-close-packed network of wax crystals. The multi-alkyl polyamines have multiple alkyl side chains that extend in different directions into the oil phase and can co-crystallize with the wax molecules, allowing the wax crystals to disperse.

中文翻译：

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多烷基多胺的合成及其作为原油流动改进剂的性能

在这项工作中，合成了三种多烷基多胺，即五十六烷基二乙烯三胺 (PHDETA)、六十六烷基三乙烯四胺 (HHTETA) 和七十六烷基四乙烯戊胺 (HHTEPA)，并作为纯原油流动改进剂进行了评估。在一定条件下，PHDETA、HHTETA和HHTEPA能够通过将原油粘度分别降低97.5%、94.3%和97.1%来改善L401原油样品的流动特性。三种合成的烷基多胺 PHDETA、HHTETA 和 HHTEPA 能够将 L1316 原油的粘度分别降低到最大 94.3%、93.7% 和 94.9%。PHDETA、HHTETA和HHTEPA分别可以使L401原油的倾点大大降低3.1°C、3.3°C和3.4°C。L1316原油与PHDETA的倾点，HHTETA 和 HHTEPA 分别大幅下降 2.8 °C、2.9 °C 和 3.2 °C。显微照片显示 L401 和 L1316 原油在 PHDETA 存在下共结晶，导致形成非紧密堆积的蜡晶体网络。多烷基多胺具有多个烷基侧链，沿不同方向延伸到油相中，并能与蜡分子共结晶，使蜡晶体分散。