Physical Properties of Gelatin Films Plasticized by Blends of Glycerol and Sorbitol
Physical Properties of Gelatin Films Plasticized by Blends of Glycerol and Sorbitol
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DOI：
10.1111/j.1365-2621.2005.tb07132.x
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发表时间：
2006-05
影响因子：
3.9
通讯作者：
Maira Thomazine;R. A. Carvalho;P. Sobral
中科院分区：
文献类型：
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作者：
Maira Thomazine;R. A. Carvalho;P. Sobral
增塑剂的添加增加了基于生物聚合物的膜的柔韧性和可加工性。然而，使用一些增塑剂会导致不期望的结果，例如这些添加剂从膜中迁移出来或在保质期期间结晶。因此，本研究的目的是评估具有不同比例的山梨糖醇和甘油的共混物在2种增塑剂浓度下对基于明胶的膜的机械、粘弹性和水蒸气阻隔性能的影响。用2 g明胶/100 mL水和25或55 g增塑剂/100 g明胶制备膜。甘油与山梨醇的比例为0：100、20：80、40：60、60：40、80：20和100：0。如预期的，增塑剂浓度从25 g增塑剂/100 g明胶增加到55 g增塑剂/100 g明胶引起柔韧性的增加以及阻力和水蒸气阻隔性的降低。关于混合物的效果，甘油比例的增加导致穿刺力、拉伸强度、弹性模量的降低，并且由于甘油的更高塑化效果而导致穿刺变形、断裂伸长率和水蒸气渗透性的增加。这种行为被解释的增塑剂的分子量，这表明，所研究的性能可以被认为是在膜中的增塑剂的分子数的函数。
The addition of plasticizers increases the flexibility and workability of films based on biopolymers. However, the use of some plasticizers cause undesirable results, such as the migration of these additives out the film or crystallization during shelf life. Thus, the aim of this study was to evaluate the effect of blends with different ratios of sorbitol and glycerol, at 2 plasticizer concentrations, on mechanical, viscoelastic, and water vapor barrier properties of films based on gelatin. The films were prepared with 2 g gelatin/100 mL of water and with 25 or 55 g plasticizer/100 g gelatin. The ratio, glycerol to sorbitol, was studied as 0:100, 20:80, 40:60, 60:40, 80:20, and 100:0. The increase of plasticizer concentration from 25 to 55 g plasticizer/100 g gelatin caused an increase of flexibility and reduction of resistance and water vapor barrier as expected. In relation to the effect of the mixture, the increase in the proportion of glycerol caused a reduction of the puncture force, tensile strength, modulus of elasticity, and an increase of the puncture deformation, elongation at break, and water vapor permeability due to the higher plasticizing effect of glycerol. This behavior was explained in terms of molecular weight of the plasticizers, which demonstrated that the studied properties could be considered as functions of the number of molecules of plasticizers in the films.