共查询到19条相似文献,搜索用时 62 毫秒
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凝胶渗透色谱(GPC)是获得高聚物各种平均分子量和分布的最重要的手段之一。在使用GPC条件下校准线作出之后,借助Benoit等提出的普适校准原理,并已知被测样品的Mark-Houwik常数时,即可很容易计算出样品的各种平均分子量,但在实际中会遇到一定的困难。人们努力寻求方便可行的办法,其中Amber,Mahabadi提出的方法取得了一定进 相似文献
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]本文提出了对未知Mark-Howink常数的一个聚合物样品,从它的特性粘数和GPC图谱得到各种平均分子量的新方法。该方法对窄分布和宽分布的样品都适用,已用三组不同分子量分布和不同K和的聚合物样品进行了验证。用该方法得到的各种平均分子量与已知K和时用传统的普适法得到的结果是一致的。 相似文献
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用简易GPC柱研究了在未知合适的Mark-Houwink 系数的情况下,通过GPC和特性粘度的数据,同时计算出宽分布硅烷亚芳弹性体聚合物的分子量和这种类型聚合物的 Mark-Houwink 系数的方法。装柱填料为多孔硅胶球,理论塔板数 4200—5500块/米以上,塔板高度 0.7—0.9毫米。其分子量分布宽度指数在2左右。素炼后,分子量分布变窄,分子量下降。 相似文献
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研究了均聚和共聚甲醛在六氟异内醇中的凝胶渗透色谱(GPC)。对共聚甲醛出现的缔合现象从主链结构作了解释,并找到了避免缔合的方法;对共聚甲醛GPC淋洗曲线上的异常小峰从聚合机理角度进行了探讨,推测得到小峰所对应的物质。确定了以六氟异丙醇为溶剂的聚甲醛的凝胶色谱表征方法,并探索采用凝胶色谱-粘度计联用法得到分子量和分子量分布结果。 相似文献
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淋洗剂凝胶渗透色谱法研究非缔合多组分溶液 总被引:2,自引:0,他引:2
A polyglycol solution containing different molecular weight PEG components was chosen as test solution. By comparing the results obtained by conventional gel permeation chromatography GPC(water as eluent, sample solution as injected solution)and Eluent-GPC (PEG sample solution as eluent, the concentrated sample solution ,diluted sample solution, water, and sample solution itself as injected solution respectively), the advantage and potential practical usage of Eluent-GPC were discussed. 相似文献
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Adrian Boborodea Alan Brookes 《International Journal of Polymer Analysis and Characterization》2015,20(2):172-179
The increasing world demand for polyphenylene sulfide (PPS) due to its unique properties has augmented the pressure on development of analytical methods to evaluate its molecular weight distribution and structure. Whilst gel permeation with triple detection (GPC3D) has been considered for PPS analysis, its development and effectiveness has been impaired because of, firstly, the high temperature needed to maintain solubility (>205°C), and, secondly, a very low dn/dc for the polystyrene calibration standards in 1-chloronaphthalene. This article presents practical recommendations to overcome these early difficulties by discussing the results obtained on PPS samples analyzed with a commercially available GPC3D instrument. 相似文献
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凝胶渗透色谱用大孔硅胶的制备 总被引:1,自引:0,他引:1
采用NaCl、LiCl~KNO33组分盐,通过一次焙烧扩孔,制备了孔径4×102~1×103nm的大孔硅胶,其孔容可达0.8mL/g,孔度为0.65以上。实验结果表明,可用于GPC分离相对分子质量为1.5×107以下的聚丙烯酰胺。 相似文献
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Adrian Boborodea François Collignon Alan Brookes 《International Journal of Polymer Analysis and Characterization》2015,20(4):316-322
This study presents the possibility of replacing the 1,2,4-trichlorobenzene (TCB) recommended by ASTM D 6474 for the analysis by gel permeation chromatography (GPC) of linear polyethylenes with dibutoxymethane (DBM, butylal), a halogen-free and less toxic solvent. The molecular weight distributions as well as the K and alpha parameters of the Mark-Houwink-Sakurada relationship were measured for polyethylene solutions in TCB and DBM, using a GPC system with triple detection (light scattering, differential refractive index, and viscometer). For commercial metallocene polyethylene resins typically used for film and packaging applications, the GPC method in DBM provided results comparable to those obtained in TCB. 相似文献