可降解pH响应型颜色指示包装膜的制备与性能

Preparation and properties of degradable pH-responsive color indicator packaging films

摘要:

以乙酰化二淀粉磷酸酯（ADSP）和聚乙烯醇（PVA）为膜基，紫甘蓝提取的花青素为指示剂，采用流延法制备了颜色指示包装膜。采用SEM、FTIR、XRD表征，基于对膜的厚度、不透明度、吸水性、透氧性等物性测定，通过拉伸强度和断裂伸长率、pH指示、挥发氨响应、土埋降解测试，考察了ADSP与PVA配比对制备的指示包装膜的微观结构、物性参数、光学和机械性能，以及pH敏感性、挥发性氨灵敏性、生物间接性的影响。结果表明，PVA与ADSP相互作用形成氢键，显著增强了指示包装膜的致密结构，ADSP溶液与PVA溶液以体积比5∶5混合制备的指示包装膜综合性能最好，其不透明度为0.112 mm–1，吸水性为24.57%，水溶性为21.23%，透氧性为26.41 g/(m2?d)，拉伸强度为15.59 MPa，断裂伸长率为301.89%，水蒸气透过率为2.98?10-10 g/(m?s?Pa)；花青素的加入可以增强指示包装膜的阻光能力，并且赋予其对pH值（2~12）明显的颜色响应性，并表现出对挥发性氨响应时间短（10 s），和检测限低（摩尔分数1×10-6）的灵敏性，并因为ADSP的加入而均具有生物可降解性。

Abstract:

Color-indicating packaging films were prepared by casting method using acetylated diastarch phosphate (ADSP) and polyvinyl alcohol (PVA) as the film base and anthocyanin extracted from purple kale as the indicator. The microstructure, physical parameters, optical and mechanical properties, and pH sensitivity, volatile ammonia sensitivity, and volatile ammonia sensitivity of the indicator packaging films prepared were investigated by using SEM, FTIR, and XRD characterization based on the physical property measurements of thickness, opacity, water absorption, and oxygen permeability of the films, as well as by tensile strength and elongation at break, pH indicator, volatile ammonia response, and soil-buried degradation tests, which investigated the microstructure, physical parameters, and optical and mechanical properties of the indicator packaging films prepared in the ratio of ADSP to PVA, as well as pH sensitivity, volatile ammonia sensitivity , and bioconsequential effects. The results showed that the interaction between PVA and ADSP formed hydrogen bonds, which significantly enhanced the dense structure of the indicator packaging film, and the indicator packaging film prepared by mixing ADSP solution with PVA solution at a volume ratio of 5:5 had the best overall properties, with an opacity of 0.112 mm-1, a water absorption of 24.57%, a water solubility of 21.23%, an oxygen permeability of 26.41 g/(m2?d), tensile strength of 15.59 MPa, elongation at break of 301.89%, and water vapor transmission rate of 2.98?10-10 g/(m?s?Pa); The incorporation of anthocyanins enhanced the light-blocking ability of the indicator packaging films and conferred them with significant color responsiveness to pH (2~12), and exhibited a short response time (10 s) to volatile ammonia, and sensitivity to a low detection limit (molar fraction of 1×10-6), and were all biodegradable because of the incorporation of ADSP.