Correlation analysis between biodegradable nature and microstructure of functional hybrid materials using biomass

首先，基于草酸水溶液存在下的反应裂解气相色谱，建立了一种直接快速测定甲壳素乙酰化度的新方法。根据特征热解产物的峰强度准确地确定了乙酰化度。测定值与~1H-核磁共振及其它方法的结果吻合较好。此外，该技术适用于任何类型的甲壳质样品，包括结晶度较高的不溶性甲壳素和完全乙酰化的人造甲壳素，但^1H核磁共振不适用于这些样品。其次，通过程序升温热解(TPPy)-质谱仪和TPPy原子发射光谱对甲壳素衍生物/聚氯乙烯(PVC)杂化材料的相容性和分子间相互作用部位进行了表征。与各自共混聚合物的降解过程相对应，杂化材料通常表现为明显的三个阶段的分步降解。然而，每个降解峰的温度被证明与杂交物的混相性相关。此外，在聚氯乙烯的脱氯化氢阶段，在低于300ﾟC的较低温度下，甲壳素衍生物和聚氯乙烯形成的许多特征产物的演化引发了甲壳素衍生物的降解，甲壳素衍生物应该稳定到约350ﾟC。

Firstly, anew method to determine directly and rapidly the degree of acetylation of chitin was developed based on reactive pyrolysis-gas chromatography in the presence of an oxialic acid aqueous solution. The degree of acetylation was precisely determined on the basis of peak intensities of the characteristic pyrolysis products. The observed values were in good agreement with those obtained by ^1H-NMR and the other methods. Moreover, the proposed technique was applicable to any kinds of chitin samples over the whole range of acetylation including insoluble chitin and perfectly acetylated artificial chitin having higher crystallinity to which ^1H NMR had been inapplicable.Next, chtin derivative/poly(vinyl chloride) (PVC) hybrids were characterized mainly in terms of their miscibility and sites of the intermolecular interactions by temperature programmed pyrolysis (TPPy)-mass spectrometry and TPPy-atomic emission detection. Stepwise degradation apparently in three stages was commonly observed for the hybrids corresponding to the degradation of the respective blending polymers. However, each degradation peak temperature proved to change correlating to the miscibility of the hybrids. Moreover, during the dehydrochlorination stage for PVC at relatively lower temperatures below 300ﾟC, the evolution of many characteristic products formed from the chitin derivative and PVC were triggering the degradation of the chitin derivatives which should be stable up to ca. 350ﾟC.