利用流動注射高分子分析法配合靜態光散射偵測器證明樹枝狀高分子聚合物的分子量與光散射強度之間的尺度關係並探討其應用

Using Flow Injection Polymer Analysis to Verify The Scaling Relation of Static Light Scattering Intensity versus Dendrimer Molecular Weight and Its Applications

曾惠鈺(Hui-Yu Tseng)

指導教授 ： 王少君

國立中正大學/理學院/化學暨生物化學系/碩士(2014年)

摘要

利用流動注射高分子分析法 (Flow Injection Polymer Analysis, FIPA) 結合直角度 (90°)雷射光光散射儀 (Right-Angle Laser Light Scattering，簡稱RALLS)來對樹枝狀高分子 (dendrimer)進行靜態光散射檢測。由於樹枝狀分子的結構大多類似於硬球狀，並非一般的random coil或rod-like構形，故無法使用一般標準品如PEO(polyethylene oxide)或Dextran來校正儀器因子，進而正確計算樹枝狀高分子之分子量。有鑑於此，我們將利用光散射儀原理中Rayleigh方程式所提到的光散射訊號強度除以濃度會正比於真實分子量的關係來建立尺度關係 (scaling relation)圖。
以已知具有高純度且修飾上吡啶 (pyridine)外圍官能基的聚乙二胺樹枝狀高分子和未修飾上吡啶的聚乙二胺樹枝狀高分子 (修飾上吡啶，分子量範圍：24134至197938 Da；未修飾吡啶，分子量範圍：14215至116493 Da)，在稀薄溶液下進行實驗。分別將4至7代樣品所提供的理論分子量與流動注射高分子分析法 (FIPA)測得的RALLS強度積分面積除以濃度值進行線性回歸，實驗結果皆可得到高度相關性，證實兩者的確能具有良好的尺度關係。接著還利用混合其他代數的不純樣品進行線性回歸，得到的R2值明顯下降許多。由以上結果可知，只要樹枝狀高分子樣品的純度不夠，建立出的檢量線就無法得到良好的尺度關係。
利用高純度樣品所建立的尺度關係對一系列未完全反應的樹枝狀樣品進行研究，從實驗結果可知只要樣品不夠純，數據點就會依照程度不同而偏離線性關係，藉此可知的確能將此方法應用於檢測樹枝狀樣品是否為不純物。
除此之外，我們還將可能受到樣品秤重影響而造成誤差的濃度值利用折射計訊號值來取代，最後結果也都能獲得良好的尺度關係；因此即便樣品為一未知濃度的樣品，仍可利用此方法來進行樹枝狀高分子的檢驗或是建立尺度關係。
目前在樹枝狀高分子的合成當中，合成出的樹枝狀產物可能同時含有未完全轉換的其他代數高分子，造成其純度不定。綜觀以上結果，我們推斷應可使用較易獲取的低代數樹枝狀高分子先建立良好的尺度關係後，再用來檢測同類型的較高代數樹枝狀高分子是否具有良好的純度。本方法不僅簡單快速，且不需使用常見用來檢測樹枝狀高分子的昂貴儀器，如：核磁共振儀 (Nuclear magnetic resonance, NMR)與基質輔助雷射脫附游離飛行時間質譜儀 (Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectrometry, MALDI-TOF MS)，因此也不會受到此兩種方法在檢測樹枝狀高分子的限制。

關鍵字

樹枝狀高分子 ； 膠體滲透層析儀

並列摘要

Unlike the configuration of long chain polymers such as random coil or rod-like shape the structures of dendrimer are of a rigid sphere. Therefore conventional polymer standards like polyethylene oxide (PEO) or dextran are not applicable to calibrate static light scattering (SLS) detector to directly determine the molecular weight (M.W.) of dendrimers. To overcome this limitation, in this thesis having verified the scaling relation of static light scattering intensity per concentration versus molecular weight of dendrimer,we use this relation for M.W. estimations.
The solutions of poly (amidoamine) (PAMAM) dendrimers and pyridine modified PAMAM dendrimer standards ranging from the fourth to seventh generation sizes were used to establish the above scaling relationusing flow injection polymer analysis (FIPA) with right angle laser light scattering (RALLS) detection. The high linearity between the LS intensity per concentration and M.W. value is proved. We also used artificial impure samples which mixed with other generation dendrimers to examine the validity of linear scaling relation. However, the R square values were significantly decreased.
We also measured the M.W. of impure dendrimers by substituting the scattering LS intensity per concentration in the established. Considerable deviations from the M.W. of standards were found.
In addition,we usedRI signal to replace the concentration of the sample which may be weighing error.The final results can get a good scaling relationship.When the unknown concentration of the sample, we still can use this method to test dendrimer usingscaling relationships.
We infer that we can firstly use the available dendrimer standards to establish a scaling relation, and to examine the purity of synthesized dendrimer of higher generations. This method requiredaffordable equipment is straightforward without using state-of-the-arts expensive equipment such as Nuclear Magnetic Resonance (NMR) or Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectrometry (MALDI-TOF MS).

並列關鍵字

Dendrimer ； Gel Permeation Chromatography, GPC

參考文獻

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