偏振拉曼光谱法定向测定聚乙烯

结合偏振显微拉曼系统和IQ框架的旋转对准功能，准确地评估了聚乙烯的取向状态。这种组合可用于评估各种聚合物膜和纤维（如聚对苯二甲酸乙二醇酯和聚丙烯）的取向。示例：Application Note030-AN-0024 Orientation measurement of polyethyleneby polarized Raman spectroscopy2/3Application Note In this note， we i ntroduce the results of the orientation analysis of a polyethylene string using a polarized microscopic Raman system and the lQ Frame. Keyword s Raman spectroscopy， po l arization， polyethy l ene ， IQ Frame Experimental A polyethylene string was aff i xed o n a metal plate and set i n the IQ Frame*2. In t he measurement， the analyzer was placed so the sample was parallel to the polarization direc t ion of the inc i dent light (laser)， and the polarized Raman scatter i ng parallel to the i ncident light was d e tected. T h e sample was rotated i n 10o steps using the scale on the IQ Frame， and Rama n spectra were obtai n ed at each of the 36 points (total 360o) using the rotational alignment func t ion of the IQ Frame. Rotational alignment function After rotat i ng the sample unde r the microscope， it is a challenge to align exactly a t the same measurement position.The rotational alignment f unction mentioned in this note uses the image matching technology of t h e IQ Frame， and the measurement position can be al i gned accurately and quickly even if the sample is rotated. It is especially effective when evaluating the orientation of a heterogeneous sample. Exampl e： M e as uremen t a f t e r rota te d 45° Figure 2. I m ag e o f rot at ion al a l ignmen t func t ion Measurement Conditions： Raman Microscopic System Main Unit NRS-4500 Raman spectrometer Ex Wavelength 532nm Objective Lens 20X Exposure Time 3 seconds Accumulation 2 times Figure 3. NRS-4500 Rama n spect r o meter Results First， it can be conf i rmed from the optical images shown i n Figure 5 that the same point can be measured at each angle As a result of obtaining Raman spectra by rotat i ng the polyethylene string by 360°， changes were observed in the peak of C-C skeletal vibrat i on indicated by the arrow in the spectrum of Figure 4. The peak of C-C skeletal vibration is closely related to the degree of orientation. From the results i n Figure 5 in which the peak i ntensities were plotted for each angle，it was confirmed an 8-shaped i ntens i ty distribution with maxima at 0° and 180°. Therefore， it was suggested that the polyethylene string measured was strongly stretched uniaxially in the laser polarization direction (horizontal direction on the paper) at 0° and 180°. JASCO IN C. 28600 Mary's Cour t ， E asto n， MD 21601US A A ppli c a tio n Lib r ary： jasc o i n c.com /appli c ati o ns F i gure 4. Ea c h sp e ctr um at 0°，90°180° Figure 5. Pea k i n tens iti es p lot and ob served ima ge Conclusion Combining the polarized microscopic Raman system and the rotational al i gnment funct i on of the IQ F r ame， the orientation state of the polyethylene string was evaluated accurately. This combinat i o n could be used to evaluate t he orientation of various polymer f i lms and fibers such as polyethylene terephthalate and polypropylene. *1 Raman Application Note： 210-AN-0019 *2 Raman Application Note： 210-AN-0016 System Configuration Model Description Part Number Main Unit NRS-4500-532 Raman Spectrometer 7118-JO51A Options RAP4-745 Automatic polarization measurement unit (0/90 6882-J501A degree switching) SHO2-RM IQ Frame for Raman 7071-J137A