改性玉米苞叶纤维素/纳米滑石粉/豌豆淀粉复合膜的制备及性能表征

Preparation and Characterization of Modified Corn Bract Cellulose/Nano Talcum Powder/Pea Starch Composite Film

为开发绿色可降解的食品包装材料,本文以豌豆淀粉(pea starch,PS)为主要成膜基质,改性玉米苞叶纤维素(modified corn bract cellulose,MCBC)、纳米滑石粉(nano talcum powder,NTP)为增强材料,甘油为增塑剂,共混流延制备复合膜,测定其膜性能,并用扫描电子显微镜、傅里叶红外光谱对复合膜进行表征,最后对其进行热重分析与降解性分析。结果表明,经单因素实验及正交试验得到最佳复合膜制备工艺为PS 8%,甘油2.5%,MCBC 0.8%,NTP 0.15%,在此条件下制得的复合膜厚度为0.042 mm,透光率32.58%,抗拉强度32.48 MPa,断裂伸长率33.61%,水蒸气透过率0.19×10^(−10)g/(m·s·Pa),透油系数0.006 g·mm/m^(2)d,吸水率55.79%,溶解度18.04%。扫描电子显微镜(scanning electron microscopy,SEM)结果显示,复合膜表面光滑均匀,结构致密;傅里叶红外光谱(Fourier transform infrared spectroscopy,FTIR)结果显示,MCBC、NTP、PS三者之间相容性良好,分子间氢键作用增强;热重分析(thermal gravimetric analyzer,TGA)结果显示,复合膜热分解温度为318.12℃,热稳定性提高;降解性分析表明土壤掩埋8 d时自然降解率为96.47%,可完全生物降解,本研究为MCBC/NTP/PS复合膜在食品工业中的应用提供了参考。

The study aimed to develop green degradable food packaging materials.Here,the composite film was prepared by tape casting method,which pea starch(PS)was used as the main film-forming matrix,modified corn bract cellulose(MCBC)and nano talcum powder(NTP)were used as reinforcing material and glycerin was used as plasticizer.The properties of the composite membrane were determined,and the composite membrane was characterized by scanning electron microscope and Fourier infrared spectroscopy.Finally,the thermogravimetric analysis and degradation analysis were carried out.Results showed that,the optimal preparation conditions of composite film including PS 8%,glycerol 2.5%,MCBC 0.8%,NTP 0.15%by using the method of single factor experiments and orthogonal experiment.Under these conditions,the thickness of composite film was 0.042 mm,the transmittance was 32.58%,the tensile strength was 32.48 MPa,the elongation at break was 33.61%,the water vapor transmission was 0.19×10^(−10)g/(m·s·Pa),the oil permeability coefficient was 0.006 g·mm/m^(2)d,the water absorption rate was 55.79%and the solubility was 18.04%.The results of scanning electron microscopy(SEM)showed that the surface of the composite film was smooth and uniform,and the structure was compact.The results of fourier transform infrared spectroscopy(FTIR)showed that MCBC,NTP and PS were compatible well,and the intermolecular hydrogen bond of them were enhanced.Moreover,the results of thermal gravimetric analyzer(TGA)showed that the decomposition temperature of composite film was 318.12℃,and the heat stability of composite film was improved.Degradation analysis also showed that the natural degradation rate of composite film was 96.47%after being buried in soil for 8 days,therefore,the composite film could be biodegraded completely.The study would provide a reference for the application of MCBC/NTP/PS composite film in food industry.