ABSTRACT The aim of this study is to analyze the various compositions of polyvinyl alcohol (PVA) and starch (S) blends. The blends have been cross-linked with glutaraldehyde to enhance its properties. The hydroxyl groups of PVA and starch react with glutaraldehyde via formation of acetal bonds hence crosslinking could take place. The cross-linking of glutaraldehyde is observed with the help of various analytical methods such as differential scanning calorimetry (DSC) and Fourier-transform infrared spectroscopy (FTIR). The presence of two highly reactive alpha protons makes glutaraldehyde more reactive and acidic in nature. The higher reactivity of glutaraldehyde, at higher dosages leads to reduction in H-bonding of PVA and starch. The cross-linked blends showed better thermal and mechanical properties. Viscosity, tensile strength, pencil hardness, and ultimate stress were evaluated to estimate the changes due to cross-linking. It was observed that the mechanical properties are directly proportional to the amount of starch as the starch hydroxyl groups are easily accessible for the cross-linking reaction. The cross-linked blend showed better cohesion between its chains, thereby increasing the glass transition temperature. It was reflected in the subsequent increase in tensile strength properties.

中文翻译：

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戊二醛对淀粉和聚乙烯醇共混物热力学性能的影响

摘要 本研究的目的是分析聚乙烯醇 (PVA) 和淀粉 (S) 混合物的各种成分。该混合物已与戊二醛交联以增强其性能。PVA 和淀粉的羟基通过形成缩醛键与戊二醛反应，因此可以发生交联。借助差示扫描量热法 (DSC) 和傅里叶变换红外光谱 (FTIR) 等各种分析方法，可以观察戊二醛的交联。两个高反应性 α 质子的存在使戊二醛在性质上更具反应性和酸性。戊二醛在较高剂量下的较高反应性导致 PVA 和淀粉的 H 键减少。交联的共混物显示出更好的热性能和机械性能。粘度、抗张强度、铅笔硬度、和极限应力被评估以估计由交联引起的变化。据观察，机械性能与淀粉的量成正比，因为淀粉羟基很容易进行交联反应。交联混合物在其链之间表现出更好的内聚力，从而提高了玻璃化转变温度。这反映在随后拉伸强度性能的提高上。