Microstructural studies on BaCl2 doped poly(vinyl alcohol)
Microstructural studies on BaCl2 doped poly(vinyl alcohol)
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DOI：
10.1016/j.polymer.2006.03.054
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发表时间：
2006-05-03
期刊：
影响因子：
4.6
通讯作者：
Poojary, Boja
中科院分区：
文献类型：
--
作者：
Bhajantri, R. F.;Ravindrachary, V.;Poojary, Boja
研究了BaCl_2掺杂对聚乙烯醇（PVA）光学和微观结构的影响。采用溶剂浇铸法制备了纯PVA和BaCl 2掺杂PVA薄膜。采用FTIR、UV-可见光、XRD和DSC等技术对薄膜进行了表征。在FTIR光谱中观察到的3425 cm（-1）、1733 cm（-1）和1640 cm（-1）峰分别归属于O-H、C=C伸缩振动和乙酰基C=O基团振动。在掺杂的PVA中，这些谱带的位移可以根据与PVA的相邻OH基团的分子内/分子间氢键来理解。紫外-可见光谱显示掺杂PVA在196 nm附近的吸收带和在208 nm附近的肩峰具有不同的吸收强度，它们被归属于n -> pi* 跃迁。这表明不饱和键主要存在于聚合物的尾-头中。光学带隙估计使用紫外-可见光谱，它随着掺杂剂浓度的增加而减小。粉末XRD显示掺杂PVA的结晶度增加，这是由于掺杂剂与PVA的相互作用引起聚合物的无定形相内的分子重排而引起的。这些改性也影响掺杂聚合物的光学性质。DSC研究还支持由于掺杂而增加的晶体厚度和结晶度。(c)2006爱思唯尔有限公司保留所有权利。
We have studied the effect of BaCl2 dopant on the optical and microstructural properties of a polymer poly(vinyl alcohol) (PVA). Pure and BaCl2 doped PVA films were prepared using solvent casting method. These films were characterized using FTIR, UV-visible, XRD and DSC techniques. The observed peaks around 3425 cm(-1), at 1733 cm(-1) and 1640 cm(-1) in the FTIR spectra were assigned to O-H, C=C stretching and acetyle C=O group vibrations, respectively. In the doped PVA shift in these bands can be understood on the basis of intra/inter molecular hydrogen bonding with the adjacent OH group of PVA. The UV-visible spectra shows the absorption bands around 196 nm and shoulders around 208 nm with different absorption intensities for doped PVA, which are assigned to n -> pi* transition. This indicates the presence of unsaturated bonds mainly in the tail-head of the polymer. Optical band energy gap is estimated using UV-visible spectra and it decreases with increasing dopant concentration. The powder XRD shows an increase in crystallinity in the doped PVA, which arises due to the interaction of dopant with PVA causing a molecular rearrangement within the amorphous phase of polymer. These modifications also influence the optical property of the doped polymer. The DSC study also supports increasing crystalline thickness and degree of crystallinity due to doping. (c) 2006 Elsevier Ltd. All rights reserved.