Molecular weights of poly(butyl cyanoacrylate) nanoparticles determined by mass spectrometry and size exclusion chromatography
Molecular weights of poly(butyl cyanoacrylate) nanoparticles determined by mass spectrometry and size exclusion chromatography
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DOI：
10.1016/j.ejpb.2005.02.009
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发表时间：
2005-08-01
影响因子：
4.9
通讯作者：
Kreuter, J
中科院分区：
文献类型：
--
作者：
Bootz, A;Russ, T;Kreuter, J
采用基质辅助激光解吸电离飞行时间质谱（MALDI-TOF MS）和尺寸排阻色谱（SEC）研究了乳液聚合法制备的聚氰基丙烯酸丁酯（PBCA）的化学组成、平均数均分子量（M-n）、平均重均分子量（M-w）和多分散性（PD）。两种方法对M-n给出了相似的结果，但对M-w和PD观察到了实质性差异，MALDI产生的值始终较低，这不能通过SEC和MALDI的离线偶联来改善。MALDI对氰基丙烯酸酯的化学组成给出了更详细的看法，并揭示了除了预期的PBCA系列之外，还存在两种具有不同端基的额外聚合物系列，其在SEC中显示出不同的保留。它们的形成是由甲醛通过（反向）Knoevenagel反应从/到常规聚合物的分离/加成来解释的。在另外的实验中，通过比较聚合产率和粒径与它们的化学组成（如MALDI光谱所揭示的）来检查聚合期间不同pH对PBCA-NP的影响。在pH I下产生具有最高聚合产率、最小粒径和质量分布的最均匀的纳米颗粒。(c)2005 Elsevier B. V.保留所有权利。
Matrix-assisted laser desorption ionisation time-of-flight mass spectrometry (MALDI-TOF MS) and size exclusion chromatography (SEC) were employed to elucidate the chemical composition, mean number average molecular weight (M-n), mean weight average molecular weight (M-w), and polydispersity (PD) of poly(butyl cyanoacrylate) (PBCA) manufactured by emulsion polymerisation. Both methods gave similar results for M-n, but substantial differences were observed for M-w and PD, with MALDI producing consistently lower values which could not be improved by off-line coupling of SEC and MALDI. MALDI gave a more detailed view on the chemical composition of the cyanoacrylate and revealed the presence of two additional polymer series with different end groups besides the expected PBCA series, which showed different retention in SEC. Their formation is explained by the secession/addition of formaldehyde from/to the regular polymer via (reverse) Knoevenagel reaction. In additional experiments, the influence of different pH on PBCA-NP during polymerisation was examined by comparison of polymerisation yield and particle diameter to their chemical composition as revealed by the MALDI spectra. The most uniform nanoparticles, with the highest polymerisation yield, narrowest particle size, and mass distribution were produced at pH I. (c) 2005 Elsevier B.V. All rights reserved.