【作者】 周莹； 赵晓雅； 苏敦凡； 洪崧； 陈晓农；

【Author】 Ying Zhou;Xiaoya Zhao;Dunfan Su;Song Hong;Xiaonong Chen;College of Materials Science and Engineering,Beijing University of Chemical Technology;Department of Chemical Engineering,Hengshui University;

【机构】 北京化工大学材料科学与工程学院； 衡水学院化学工程系；

【摘要】 在本研究工作中,利用红外光谱法测定聚苯乙烯-聚异丙基丙烯酰胺(PS-PNIPAM)嵌段聚合物的各组分比例,发现红外(IR)定量分析结果与核磁氢谱(1H-NMR)的结果存在显著偏差,进而发现两亲性聚合物PS-PNIPAM的IR谱图中苯乙烯上的苯环吸收峰发生蓝移,异丙基丙烯酰胺上的异丙基峰发生红移现象。由此推测可能由于PS与PNIPAM的不相容性,导致该嵌段聚合物发生微观相分离进而影响红外特征峰值。为此,采用MATLAB软件对相分离聚合物的TEM图像进行处理,计算单位面积中相分离边界的周长,将该周长数值与偏移谱峰的强度、相分离状态(双连续、球形相分离等)进行关联。结果表明相关谱峰偏移程度与相分离形态之间存在定量关系,即谱峰偏移程度越大,相分离聚合物界面周长越大。以此为基础建立了通过IR波谱分析判断两亲聚合物微观相分离形态的新方法。更多还原

【Abstract】 Abstrate: In the present work, infrared spectroscopy(IR) spectrum was initially recorded to measure the composition of amphiphilic styrene-N-isopropylacrylamide(PS-PNIPAM) block copolymers prepared via reversible addition fragmentation chain transfer(RAFT) polymerization. It was found that the composition calculated based on the IR spectra of the copolymers was quite different from that obtained by 1H nuclear magnetic resonance(1H-NMR) measurement. Meanwhile, transmission IR spectra of block and graft copolymers of N-isopropylacrylamide with styrene showed a blue shift of the band associated to the phenyl ring of styrenic moieties and a red shift of the band assigned to the isopropyl groups of NIPAM units. Since poly(N-isopropylacrylamide)(PNIPAM) is immiscible with polystyrene(PS), the phase separation morphology of the amphiphilic copolymers influenced the peak characters in their infrared spectra. Differential IR absorbance around the bands related to the phenyl ring was linked to the interfacial characteristic observed from transmission electron microscopy(TEM) images of the copolymer specimen. In image TEM data process, MATLAB was employed to calculate interfacial length in the image, which provided quantitative information on morphological features. The synthetic work, composition characterization and morphology investigation were completed to reveal clear link between the band character in IR spectrum of amphiphilic copolymer and its phase separation morphology. Our aim is to establish a simple IR-based approach to predict potential morphology of amphiphilic copolymer system.更多还原