Preparative gel permeation chromatography of Athabasca asphaltene and the relative polymer-forming propensity of the fractions
Preparative gel permeation chromatography of Athabasca asphaltene and the relative polymer-forming propensity of the fractions
复制标题
阿萨巴斯卡沥青质的制备型凝胶渗透色谱和各馏分的相对聚合物形成倾向
DOI：
10.1016/0016-2361(83)90097-2
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发表时间：
1983
期刊：
影响因子：
7.4
通讯作者：
O. Strausz
中科院分区：
文献类型：
--
作者：
T. Ignasiak;L. Kotlyar;N. Samman;Douglas S. Montgomery;O. Strausz
阿萨巴斯卡沥青质已根据 Bio-Beads SX-1 凝胶上的分子量进行分离。通过该分馏获得的五个任意级分的数均分子量范围为1200至17000。这些级分的化学、光谱和热性质都相似，但它们的聚合物形成倾向明显不同。后一性质的重要性是根据 300 °C 热解时产生的 CH2Cl2 不溶性物质的量来定义的，随着级分分子量的增加而迅速增加。相比之下，在相同条件下，整个沥青质在 300°C 时不会形成聚合物，因此得出结论，链增长步骤被沥青质团聚体中包含的各种抑制剂终止。在凝胶渗透色谱分离过程中，沥青质中存在的粘土浓缩在较高分子量的馏分中。这种吸引粘土的亲和力被认为与这些较高分子量材料的物理性质而非化学性质有关。粘土还对沥青质馏分的聚合发挥催化作用，该催化作用在最高分子量馏分中最为明显，并随着分子量的降低而逐渐减弱。
Athabasca asphaltene has been separated according to molecular weight on Bio-Beads SX-1 gel. The number-average molecular weights of the five arbitrary fractions obtained by this fractionation range from 1200 to 17000. The chemical, spectral and thermal properties of the fractions are all similar but their polymer-forming propensities are markedly different. The significance of this latter property, which is defined in terms of the amount of CH2Cl2-insoluble material produced upon thermolysis at 300 °C, increases rapidly with increasing molecular weight of the fraction. In contrast the whole asphaltene does not form polymer at 300 °C under the same conditions and it is concluded that the chain propagating steps are terminated by a variety of inhibitors that are contained in the asphaltene agglomerate. During gel permeation chromatography separation the clay present in the asphaltene concentrates in the higher-molecular-weight fractions. This affinity to attract the clay is thought to be related to the physical, and not the chemical, properties of these higher-molecular-weight materials. The clay also exerts a catalytic effect on the polymerization of the asphaltene fractions which is most pronounced in the highest-molecular-weight fraction and gradually decreases with decreasing molecular weight.