表面光交联对热塑性淀粉力学和耐水性能的影响

Effect of Surface Photo-crosslinking on Mechanical Properties and Water Resistance of Thermoplastic Starch

通过挤出注塑工艺制备了热塑性淀粉(TPS),将溶于乙醇的光引发剂二苯甲酮制成溶液涂覆于TPS表面后进行紫外光照射,研究了紫外光照射时间对TPS力学性能、动态热力学性能及耐水性能的影响。结果表明,当辐照时长为15min时,TPS表面能形成最佳的交联网络状结构,使力学和耐水性能得到显著改善;此时TPS的拉伸强度、弯曲强度、冲击强度最高分别为5.28、5.83 MPa和73.99kJ/m^2,储存模量提高,损耗因子峰值对应的转变温度分别提高到-45.40、60.60℃,接触角最高为96.8(°)。

Thermoplastic starch（TPS）was prepared by extrusion and then injection molded into the test bars.The ethanol solution containing benzophenone was coated on the surface of TPS and the irradiated by UV light.The effect of UV irradiation time on the mechanical performance,dynamic thermomechanical properties and water resistance of TPS was investigated intensively.The results indicated that an optimum cross-linked network structure was formed with UV irradiation for15 min,which led to an effective improvement in mechanical properties and water resistance.In this case,the resulting TPS achieved the maximum tensile strength of 5.28 MPa as well as the flexural strength of 5.83 MPa and impact strength of 73.99 kJ/m^2.Moreover,the TPS presented two loss factor peaks at -45.40 and 60.60 ℃ with an improved storage modulus,and it also exhibited the highest surface contact angle of 96.8°.