Preparation and characterization of plasticized gelatin films cross-linked with low concentrations of Glutaraldehyde
Preparation and characterization of plasticized gelatin films cross-linked with low concentrations of Glutaraldehyde
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DOI：
10.1007/s10853-011-6167-3
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发表时间：
2012-04-01
影响因子：
4.5
通讯作者：
Ruseckaite, R. A.
中科院分区：
文献类型：
--
作者：
Martucci, J. F.;Accareddu, A. E. M.;Ruseckaite, R. A.
热性能和机械性能以及防潮性和水蒸气阻隔性的薄膜从牛明胶添加D-山梨糖醇（30重量%）作为增塑剂和交联与低量的戊二醛（GTA，从0到2重量%）进行了研究，以确定其作为软包装材料的阻隔层的适用性。结果表明，明胶的游离氨基侧链基团随着GTA的减少而减少，证实了GTA与明胶之间发生交联。与未增塑的对应物相比，在d-山梨糖醇存在下的交联反应的程度较低，这表明增塑剂阻碍GTA反应。从差示扫描量热法（DSC）测量的玻璃化转变温度（T（g））增加与GTA浓度由于形成更多的网状材料，而d-山梨醇的掺入导致该参数的一个小的减少，由于塑化。将GTA浓度从0增加到1重量%引起弹性模量从3.7 +/-A0.2增加到4.9 +/-A0.2 GPa。这些值通过添加d-山梨糖醇显著降低，而断裂伸长率提高约150%。用于预期目的的最佳配方是含有1重量% GTA和30重量% d-山梨糖醇的配方，因为它表现出最佳的一组性能：总可溶性物质从100%减少到16%，吸湿性从1854.1 +/-A85减少到210.4 +/-A8%，65%相对湿度下的水蒸气渗透率从2.42 +/- A 0.27提高到0.94 +/- A 0.06 × 10（-14）kg mPa-1 s（-1）m（-2），不透明度略有降低，并且具有仅释放初始GTA含量的5%的额外益处。
Thermal and mechanical properties as well as moisture resistance and water vapor barrier properties of films from bovine gelatin added with d-sorbitol (30 wt%) as plasticizer and cross-linked with low amounts of glutaraldehyde (GTA, from 0 to 2 wt%) were investigated to determine their suitability as barrier layers for flexible packaging materials. Results revealed that free amino side chain groups of gelatin decreased with GTA, confirming the occurrence of cross-linking between GTA and gelatin. The extent of cross-linking reaction in the presence of d-sorbitol was lower compared with the unplasticized counterpart suggesting that plasticizer hampers GTA to react. The glass transition temperature (T (g)) as measured from differential scanning calorimetry (DSC) increased with GTA concentration owing to the formation of more reticulated materials while the incorporation of d-sorbitol led to a small reduction in this parameter due to plasticization. Increasing GTA concentration from 0 to 1 wt% provoked the enhancement of elastic modulus from 3.7 +/- A 0.2 to 4.9 +/- A 0.2 GPa. These values reduced significantly by the addition of d-sorbitol, whereas elongation at break improved in about 150%. The optimum formulation for the intended purpose was that containing 1 wt% GTA and 30 wt% d-sorbitol since it exhibited the best set of properties: total soluble mater reduced from 100 to 16%, moisture absorption decreased from 1854.1 +/- A 85 to 210.4 +/- A 8%, water vapor permeability at 65% relative humidity improved from 2.42 +/- A 0.27 to 0.94 +/- A 0.06 x 10(-14) kg m Pa-1 s(-1) m(-2), with minor reduction in opacity and with the additional benefit of releasing only 5% of the initial GTA content.