热塑性辐照玉米淀粉薄膜的制备及表征

Fabrication and Characterization of Thermoplastic Irradiated Corn Starch Films

为了提高热塑性淀粉基薄膜的力学性能,采用0、10、20、30、40、50 kGy 6个剂量的^(60)Co-γ射线对玉米淀粉进行辐照处理,研究辐照对玉米淀粉结构、颗粒尺寸的影响;并以辐照玉米淀粉为原材料,采用挤出造粒、熔融吹塑法制备热塑性辐照玉米淀粉薄膜,研究辐照剂量对热塑性薄膜力学性能、表面形貌的影响。结果表明,^(60)Co-γ射线能够有效破坏玉米淀粉分子内、分子间氢键,降低玉米淀粉的刚性;能够有效减小玉米淀粉的颗粒尺寸,增加玉米淀粉的加工流动性。随着辐照剂量的增加,热塑性辐照玉米淀粉薄膜的力学性能不断增加;未熔融颗粒不断减少,表面形貌更加均匀、平整。综合考虑热塑性辐照玉米淀粉薄膜的力学性能和钴源能耗,40kGy剂量辐照的玉米淀粉制备的热塑性淀粉基降解薄膜更具有实用价值。本研究结果为辐照玉米淀粉制造热塑性降解薄膜提供了理论依据和实际参考。

For improving the mechanical properties of starch based thermoplastic films, corn starch was exposed to 60Co -γ ray irradiation at doses 0, 10, 20, 30, 40, and 50 kGy, respectively. The effects of irradiation on the structure and particle size of irradiated corn starch were investigated. Then, the thermoplastic films were prepared by extrusion granulation and blowing method using irradiated corn starch as raw materials. The effects of irradiated doses on mechanical properties and surface structures of thermoplastic films were investigated. These results showed that 60Co -γ rays can effectively break corn starch molecules＇ hydrogen bonds and reduce the polymer rigidity. In addition, 60Co-γ rays can effectively decrease corn starch molecules＇ particle size and improve the processing flow properties. The mechanical properties of thermoplastic irradiated corn starch films increased with increasing irradiation dose. And the surface of thermoplastic irradiated corn starch films became more and more smoothed with increasing irradiation dose. Consideration of the 60Co sources＇ consumption and mechanical properties, the prepared thermoplastic degradable film using 40 kGy irradiated corn starch as the main materials have more practical value. The results provided the basis of theory and practical experience for fabricating thermoplastic degradable films using irradiated corn starch.