共辐照热塑性淀粉/山梨糖醇的制备及其热塑性分析

Preparation and Thermoplastic Analysis of Co Irradiated Thermoplastic Starch/Sorbitol

为研究山梨糖醇共辐照处理对淀粉结构及其热塑性能的影响,采用高能电子束辐照淀粉/山梨糖醇,对其微观结构进行分析,并以共辐照淀粉/山梨糖醇粉末为原料,甘油为增塑剂,通过改变山梨糖醇含量,探究山梨糖醇含量对共辐照热塑性淀粉/山梨糖醇塑化性能的影响,采用扫描电子显微镜、X射线衍射仪、差示扫描量热分析仪、热重分析仪、傅里叶变换红外光谱、X射线光电子能谱(XPS)仪、力学性能测试等手段表征共辐照热塑性淀粉/山梨糖醇的微观结构及其热塑性能。结果表明:共辐照处理严重破坏了淀粉形貌,使得部分山梨糖醇附着在淀粉颗粒表面;共辐照处理不会改变淀粉的晶型;热稳定性方面,山梨糖醇共辐照处理使得样品在一定范围内热稳定性得到提高;XPS结果表明共辐照处理使玉米淀粉与山梨糖醇发生聚合反应,推断出反应位点可能出现在淀粉葡萄糖单元的C2,C3,C6碳位处;力学性能表明,共辐照山梨糖醇质量分数为15%时,对其拉伸强度改善明显,达17.3 MPa;继续增加共辐照山梨糖醇质量分数,其拉伸强度下降。

To study the effect of co-irradiation treatment with sorbitol on the structural properties and thermoplastic properties of starch,high-energy electron beams were used to irradiate sorbitol/starch and analyze its microstructure.co irradiation of starch/sorbitol was used as raw material and glycerol as plasticizer.By changing the content of sorbitol,the effect of sorbitol content on the plasticizing properties of co irradiated thermoplastic starch/sorbitol was studied,scanning electron microscope,X-ray diffractometer,dynamic stability control,thermogravimetric analysis,infrared spectroscopy,X-ray photoelectron spectroscopy(XPS),mechanical property test etc.and other means were used to characterize its microstructure properties and thermoplastic properties.The results show that the co-irradiation treatment severely damaged the morphology of starch,causing some sorbitol to adhere to the surface of starch particles;co-irradiation treatment will not change the crystal form of starch;in terms of thermal stability,the co-irradiation treatment with sorbitol improves the thermal stability of the sample within a certain range;XPS indicates that co-irradiation treatment causes polymerization reaction between corn starch and sorbitol,and it is inferred that the reaction sites may be at the C2,C3,and C6 carbon positions of the starch glucose unit.The mechanical properties indicate that when the mass fraction of co-irradiated sorbitol is 15%,the fracture strength is significantly improved,reaching 17.3 MPa;continuing to increase the mass fraction of co-irradiated sorbitol resultes in a decrease in its breaking strength.