Chitosan/Hydrophilic Plasticizer-Based Films: Preparation, Physicochemical and Antimicrobial Properties
Chitosan/Hydrophilic Plasticizer-Based Films: Preparation, Physicochemical and Antimicrobial Properties
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DOI：
10.1007/s10924-013-0621-z
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发表时间：
2014-03-01
影响因子：
5.3
通讯作者：
Soto Valdez, Herlinda
中科院分区：
文献类型：
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作者：
Rodriguez-Nunez, Jesus R.;Madera-Santana, Tomas J.;Soto Valdez, Herlinda
在生物聚合物薄膜中添加增塑剂是改善其理化性能的一种很好的方法。本研究的目的是评价壳聚糖（CHI）与两种亲水性增塑剂甘油（GLY）和山梨醇（SOR）在20%和40%的浓度下对其机械、热、阻隔、结构、形态和抗菌性能的影响。以虾头发酵乳酸为原料，采用碱性脱乙酰法制备壳聚糖。壳聚糖的脱乙酰度（DA）为84 +/- a2.7，分子量为136 kDa，表明壳聚糖已形成良好的膜层。与纯壳聚糖膜相比，由CHI和GLY （20% wt%）组成的膜表现出最好的力学性能。与纯壳聚糖膜（b (o) = 8.8 +/- A 0.8）相比，含40% GLY的壳聚糖膜的断裂伸长率提高到700%以上，水蒸气透过率（WVTR）最高，为79.6 +/- A 1.9 g m(2) h(-1)，颜色为黄色（b (o) = 17.9 +/- A 2.0）。对于结构性质，傅里叶变换红外光谱（FTIR）和x射线衍射分析揭示了乙酰胺基团的相互作用和塑化膜结晶度的变化。扫描电镜结果表明，制备的壳聚糖薄膜表面光滑，无团聚现象，无孔隙，无微相分离现象。差示扫描量热法（DSC）热分析表明，纯壳聚糖膜的玻璃化转变温度（Tg）为130℃，而SOR或GLY的加入使峰值温度（120℃）降低。此外，壳聚糖膜对单核增生李斯特菌的抑菌活性测试表明，在24 h后，壳聚糖膜的抑菌活性降低了2 log。增塑剂浓度为20%的GLY足以获得具有良好力学性能的柔性壳聚糖膜，可以作为一种替代包装材料，减少合成包装膜的环境问题。
The addition of plasticizers to biopolymer films is a good method for improving their physicochemical properties. The aim of this study was to evaluate the effect of chitosan (CHI) blended with two hydrophilic plasticizers glycerol (GLY) and sorbitol (SOR), at two concentrations (20 and 40 wt%) on their mechanical, thermal, barrier, structural, morphological and antimicrobial properties. The chitosan was prepared through the alkaline deacetylation of chitin obtained from fermented lactic from shrimp heads. The obtained chitosan had a degree of deacetylation (DA) of 84 +/- A 2.7 and a molecular weight of 136 kDa, which indicated that a good film had formed. The films composed of CHI and GLY (20 wt%) exhibited the best mechanical properties compared to the neat chitosan film. The percentage of elongation at break increase to over 700 % in the films that contained 40 % GLY, and these films also exhibited the highest values for the water vapor transmission rate (WVTR) of 79.6 +/- A 1.9 g m(2) h(-1) and a yellow color (b (o) = 17.9 +/- A 2.0) compared to the neat chitosan films (b (o) = 8.8 +/- A 0.8). For the structural properties, the Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction analyses revealed an interaction in the acetamide group and changes in the crystallinity of plasticized films. The scanning electron micrographs revealed that all formulations of the chitosan films were smooth, and that they did not contain aggregations, pores or microphase separation. The thermal analysis using differential scanning calorimetry (DSC) revealed a glass transition temperature (Tg) of 130 A degrees C for neat chitosan film, but the addition of SOR or GLY elicited a decrease in the temperature of the peak (120 A degrees C). In addition, the antimicrobial activity of the chitosan films was evaluated against Listeria monocytogenes, and reached a reduction of 2 log after 24 h. The plasticizer concentration of 20 % GLY is sufficient for obtaining flexible chitosan films with good mechanical properties, and it could serve as an alternative as a packaging material to reduce environmental problems associated with synthetic packaging films.