Alexandru Ioan Cuza University, Faculty of Physics, 11 Carol I Blv., Iasi, RO-700506, Romania.
Spectrochim Acta A Mol Biomol Spectrosc. 2011 Oct 15;81(1):334-8. doi: 10.1016/j.saa.2011.06.020. Epub 2011 Jun 29.
Pure and colored with phthalazinium ylids poly(vinyl-alcohol) (PVA) foils were stretched under gentile heating. The birefringence of the thin foils was determined with a Babinet compensator standardized for yellow radiation of a Sodium lamp. The determined birefringence of the colored PVA foils is higher than that of the pure PVA foils. This fact indicates that the phthalazinium ylids facilitate the increase in the anisotropy of the stretched foils. The visible absorption electronic band of phthalazinium ylids was used to estimate the dichroic ratio and the degree of order of the ylid molecules in the stretched PVA foils. An increase in dichroism and birefringence with the degree of stretching has been evidenced for uncolored and colored PVA foils.
纯的和有色的吖啶鎓基聚（聚乙烯醇）（PVA）薄膜在温和加热下拉伸。用钠灯的黄色辐射标准化的 Babinet 补偿器来测定薄箔的双折射。彩色 PVA 薄膜的双折射比纯 PVA 薄膜的高。这一事实表明吖啶鎓基有利于拉伸薄膜各向异性的增加。吖啶鎓基的可见吸收电子带被用来估计拉伸 PVA 薄膜中 ylid 分子的二色性比和有序度。对于未着色和着色的 PVA 薄膜，随着拉伸程度的增加，二色性和双折射都有所增加。
