凝胶渗透色谱法测定PAN分子量及其分布

针对聚丙烯腈 (PAN)在二甲基甲酰胺溶剂中的缔合作用 ,通过加入硝酸钠使PAN能够按照分子量大小进行凝胶渗透色谱分离 ,本文考察了准确测定PAN分子量的色谱条件 ,并与激光光散射法的结果进行了对照 ,误差小于 2 .5 % ,并且重现性也非常好 ,相对标准偏差小于 1.6 %     

液相凝胶渗透色谱法测定顺丁橡胶分子量分布

顺丁橡胶具有优良的物理机械性能和使用性能,这种性能与分子量有着密切关系,并且受分子量分布的影响。研究了用液相凝胶渗透色谱法测定顺丁橡胶分子量分布的方法。该方法简便、快速准确、精密度高,适用于顺丁胶产品中分子量分布的测定。     

凝胶色谱法测定破乳剂分子量及分子量分布的研究

采用凝胶色谱(GPC)法,研究了以多乙烯多胺为起始剂支化线型类破乳剂分子量及其分布测定的方法,用渐近法校正来标定GPC柱,建立了测定分子量分布的校正曲线.GPC法测定结果与VPO法相比,其相对误差均在±10%以内,在国内首次得到了GPC测得破乳剂的分子量分布曲线.     

凝胶渗透色谱法测定HDPE分子质量及分子质量分布

以窄分布聚苯乙烯为标样,建立了用凝胶渗透色谱(GPC)表征高密度聚乙烯分子质量及其分布的方法,考察了在注射体积一定时样品浓度对测定结果的影响,开展了重复性实验,测定了高密度聚乙烯的分子质量及其分布。实验结果表明:GPC谱图呈双峰模式的试样一般分子质量分布较宽;样品溶液浓度在1.0mg/mL-2.5mg/mL范围内对测定结果没有明显影响。     

凝胶渗透色谱法测定HDPE分子质量及分子质量分布

以窄分布聚苯乙烯为标样，建立了用凝胶渗透色谱（GPC）表征高密度聚乙烯分子质量及其分布的方法，考察了在注射体积一定时样品浓度对测定结果的影响，开展了重复性实验，测定了高密度聚乙烯的分子质量及其分布。实验结果表明：GPC谱图呈双峰模式的试样一般分子质量分布较宽；样品溶液浓度在1．0mg／mL-2．5mg／mL范围内对测定结果没有明显影响。     

凝胶色谱法测定7000F平均分子量及分子量分布

根据７０００Ｆ在凝胶色谱柱上的淋洗特点,确定了测定其分子量及分子量分布试验条件,采用示差和粘度双检测凝色谱系统,利用谱适校正方法,不需要Ｍａｒｋ常数Ｋ、α值,可直接测定数均分子量,重均分子量,粘均分子量并给出分子量分布曲线。     

凝胶色谱法测定BOPP分子量及其分布

双轴拉伸聚丙烯(即BOPP)是一种生产薄膜的材料,分子量大小对其加工及使用性能都有很大的影响.文中通过应用示差和粘度双检测器的高温凝胶色谱系统,用窄分布聚苯乙烯为标样进行普适校正,直接测定BOPP的分子量及其分布,该方法具有简便、快速、准确的优点.     

凝胶渗透色谱法测定石油树脂的相对分子质量及相对分子质量分布

以单分散聚苯乙烯为标样,首次建立了用凝胶渗透色谱(GPC)表征石油树脂类低相对分子质量聚合物的平均相对分子质量及相对分子质量分布的方法。并进行了重复性实验,测定了不同批号的石油树脂的相对分子质量及分布。实验结果表明:树脂样品的低分子部分影响数均分子量,高分子部分影响重均分子量。     

凝胶色谱法测定破乳剂分子量及分子量分布的研究

采用凝胶色谱(GPC)法，研究了以多乙烯多胺为起始剂支化线型类破乳剂的分子量及其分布测定的方法，用渐近校正法标定GPC柱，建立了测定分子量分布的校正曲线，取得了较好的效果。     

凝胶过滤色谱测定高分子量聚乙烯醇分子量和分子量分布

用凝胶过滤色谱对高分子量聚乙烯醇分子量、分子量分布进行剖析。采用Plaquagel-OH色谱柱,0.25mol/LNaNO3,0.01mol/L Na2HPO4-NaH2PO,pH=7的缓冲溶液流动相,流速1ml/min,示差折光检测器,柱温30℃,聚环氧乙烷作标准物。该方法能显著缩短分析时间,提高准确性,可用于对高聚合度聚乙烯醇进行研究和指导生产。     

Characterization of Different Molecular Weight Fractions Separated from Utah Maltenes by Gel Permeation Chromatography

ABSTRACT

Maltenes derived from Utah bitumens were separated by gel permeation chromatography ( OPC) into fractions having number average molecular weights ( MW) in the range from 300 to 11985. The fractions were examined by vapor pressure osmometry, absorption spectrometry in the visible region as well as proton and carbon -13 NMR. The results are reported in comparison with those for the corresponding fractions separated from Athabasca maltenes. Utah fractions appeared to be more aliphatic with longer average aliphatic chains lengths. Branched and alicyciic types were more abundant in Utah samples, especially those with low MW, There was an apparent difference in the hydrocarbon structure of both Utah and Athabasca maltenes GPC     

Characterization of Different Molecular Weight Fractions Separated from Utah Maltenes by Gel Permeation Chromatography

Maltenes derived from Utah bitumens were separated by gel permeation chromatography ( OPC) into fractions having number average molecular weights ( MW) in the range from 300 to 11985. The fractions were examined by vapor pressure osmometry, absorption spectrometry in the visible region as well as proton and carbon -13 NMR. The results are reported in comparison with those for the corresponding fractions separated from Athabasca maltenes. Utah fractions appeared to be more aliphatic with longer average aliphatic chains lengths. Branched and alicyciic types were more abundant in Utah samples, especially those with low MW, There was an apparent difference in the hydrocarbon structure of both Utah and Athabasca maltenes GPC     

采用凝胶渗透色谱法快速测定润滑油沉积物

研究了用凝胶渗透色谱法（GPC）快速确定涡轮润滑油中的沉积物。该方法可测定在不同氧化时间下油样中抗氧剂的含量和相对分子质量分布的变化情况。对涡轮润滑油氧化安定性实验结果与GPC谱图中相对分子质量分布的分析对比发现,油品的氧化降解越严重,其中的抗氧剂聚合物相对分子质量就越大,相对分子质量分布也越宽。将△S／S（△S为相对分子质量高于800的增加峰值区域面积,S为新鲜油的峰值区域面积）值作为评价油品沉积物抑制能力的指标。该数值与油样氧化过程中生成的沉积物数量有很好的一致性。     

高分子聚合物凝胶的性能研究与应用

传统的修井作业井筒内流体容易进入地层,造成储层的污染。针对储层的污染问题,以天然大分子纤维素为骨架分子,接枝共聚水溶性丙烯酰胺单体,研制出一种高分子聚合物凝胶,并对该聚合物凝胶进行机理分析和性能评价。结果表明,该聚合物凝胶的成胶时间在30～600 min可控,破胶时间在1～30 d;在160℃下表观黏度仅为100 mPaws,便于现场施工注入。通过加入交联剂和催化剂控制合理的成胶时间,成胶后的聚合物凝胶完全失去流动性,能够形成高强度的凝胶塞,具有较高的承压强度。聚合物凝胶具有较好的抗污性能,对强酸、强碱、高矿化度盐水以及原油污染能保持较强的稳定性。聚合物凝胶在施工结束后能够破胶为低黏度的流体,通过连续油管或者泥浆泵循环出井筒。该聚合物凝胶在威远区块204H7-3页岩气井的修井作业中进行了应用,在120℃、45 MPa下,80 m聚合物胶塞,最高承压达72.82 MPa。聚合物凝胶较传统机械封堵,及水泥塞封堵有比较明显的优势,在修井作业、恶性漏失、封堵出水层等方面具有较好的应用前景。      

Characterization of Thermally Degraded Asphaltene Fractions Using Gel Permeation Chromatography

Petroleum asphaltene goes through three stages of mass reduction under thermogravimetric analysis from 25°C to 1,000°C at a heating rate of 1°C/min. The products from thermal degradation of asphaltene at three different temperature intervals are collected. Two residual fractions left in the sample cup are also obtained at two specific temperatures. The collected fractions and the residual fractions are characterized using gel permeation chromatography. The fraction collected between 25°C and 350°C demonstrates similar molecular weight distribution to that collected between 350°C and 450°C, with both fractions showing a typical molecular weight distribution for polymeric material. The fraction collected between 450°C and 650°C illustrates three different molecular weight distributions. The chromatogram of the residual fraction obtained at 350°C resembles that of the undegraded asphaltene. The residual fraction obtained at 450°C also demonstrates three different molecular weight distributions. The experimental data indicate that the mass reduction of asphaltene heated from 25°C to 350°C is mainly due to the evaporation of low boiling point and/or low molecular weight substances in asphaltene. Thermal decomposition and coke production occur significantly in the 350°C-450°C temperature interval. Thermal degradation continues to finish until 650°C.     

Characterization of Thermally Degraded Asphaltene Fractions Using Gel Permeation Chromatography

Abstract

Petroleum asphaltene goes through three stages of mass reduction under thermogravimetric analysis from 25°C to 1,000°C at a heating rate of 1°C/min. The products from thermal degradation of asphaltene at three different temperature intervals are collected. Two residual fractions left in the sample cup are also obtained at two specific temperatures. The collected fractions and the residual fractions are characterized using gel permeation chromatography. The fraction collected between 25°C and 350°C demonstrates similar molecular weight distribution to that collected between 350°C and 450°C, with both fractions showing a typical molecular weight distribution for polymeric material. The fraction collected between 450°C and 650°C illustrates three different molecular weight distributions. The chromatogram of the residual fraction obtained at 350°C resembles that of the undegraded asphaltene. The residual fraction obtained at 450°C also demonstrates three different molecular weight distributions. The experimental data indicate that the mass reduction of asphaltene heated from 25°C to 350°C is mainly due to the evaporation of low boiling point and/or low molecular weight substances in asphaltene. Thermal decomposition and coke production occur significantly in the 350°C–450°C temperature interval. Thermal degradation continues to finish until 650°C.