Molecular orientation and optical anisotropy in drawn films of miscible blends composed of cellulose acetate and poly(N-vinylpyrrolidone-co-methyl methacrylate)
Molecular orientation and optical anisotropy in drawn films of miscible blends composed of cellulose acetate and poly(N-vinylpyrrolidone-co-methyl methacrylate)
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DOI：
10.1021/ma062920t
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发表时间：
2007-03
期刊：
影响因子：
5.5
通讯作者：
T. Ohno;Y. Nishio
中科院分区：
文献类型：
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作者：
T. Ohno;Y. Nishio
聚（N-乙烯基吡咯烷酮）（PVP）与乙酰基取代度（DS）小于约的醋酸纤维素（CA）混溶。当乙烯基吡咯烷酮（VP）含量大于30 mol %，CA的取代度≤2.5时，VP/MMA无规共聚物也能与CA形成完全相容的共混物。用荧光偏振法和双折射定量法分别表征了含VP的乙烯基聚合物[P（VP-co-MMA）s]与CA的混溶共混物的单轴形变诱导的分子取向和光学各向异性。超过10对的CA/P（VP-共-MMA）的膜样品从含有少量的芪衍生物作为荧光探针的N，N-二甲基甲酰胺中的混合聚合物溶液浇铸，以假定每个单独的聚合物对的不同共混物组合物。通过偏振荧光强度分析发现，所有的拉伸膜都具有正的取向函数，但取向度较低。
Poly(N-vinylpyrrolidone) (PVP) is miscible with cellulose acetate (CA) with a degree of acetyl substitution (DS) of less than ca. 2.75, and a random copolymer of N-vinylpyrrolidone (VP) and methyl methacrylate (MMA) can also form completely miscible blends with CA, when the VP fraction in the copolymer is >30 mol % and the DS of CA is ≤2.5. The molecular orientation and optical anisotropy induced by uniaxial deformation of the miscible blends of the VP-containing vinyl polymers [P(VP-co-MMA)s] with CA were characterized by a fluorescence polarization method and birefringence quantification, respectively. Film samples of more than 10 pairs of CA/P(VP-co-MMA) were cast from mixed polymer solutions in N,N-dimethylformamide containing a slight amount of a stilbene derivative as a fluorescent probe, to assume different blend compositions for each individual polymer pair. Through analysis of polarized fluorescence intensity, it was found that all the drawn films gave a positive orientation function, but the ori...