TiO_(2)/淀粉/PCL共混材料的制备及表征

Preparation and Characterization of TiO_(2)/Starch/PCL Blends

目的以玉米双磷脂淀粉和聚己内酯(PCL)为原料,甘油为增塑剂,改性纳米TiO_(2)为抗菌剂,制备一种具有抗菌性能的可降解材料,并对不同淀粉/PCL质量比和不同纳米TiO_(2)添加量下制得的共混材料进行表征,以探究最佳共混比例。方法将不同质量比的淀粉/PCL混合,添加一定量的甘油作为增塑剂,并添加不同含量的纳米TiO_(2)作为抗菌剂,熔融共混并热压成型,利用力学、红外、紫外、SEM、DSC、水接触角等方法对所制备的共混材料进行性能表征。结果随着PCL含量的增加,共混材料的断裂伸长率先下降后上升,拉伸强度逐渐上升,PCL质量分数为100%时共混材料的拉伸强度较未添加提高了104%,对紫外光的屏蔽作用增强,接触角从78.2°下降到53.3°;DSC显示当淀粉的比例相对较大时,整个体系的结晶度较低,但PCL的结晶速率加快。TiO_(2)的加入未使体系发生化学变化,对共混材料的拉伸强度无明显影响,断裂伸长率先增加后减小,在TiO_(2)质量分数为0.9%时,达到最大为51.69%。TiO_(2)的加入对共混材料紫外线的阻隔作用有所提升,对共混材料的水接触角影响较小。抗菌实验结果显示,TiO_(2)赋予了共混材料一定的抗菌能力,且随着TiO_(2)含量的升高,抗菌性能越强。结论在PCL的质量分数为100%,即淀粉/PCL质量比为1∶1时,添加质量分数为0.9%的改性纳米TiO_(2),得到的共混材料各项性能相对较好,这为制备可降解抗菌包装材料提供了参考。

Using corn diphospholipid starch and polycaprolactone(PCL)as raw materials,glycerin as plasticizer,and modified nano TiO_(2) as antibacterial agent,a degradable packaging material with antibacterial properties was prepared.The blends prepared under different starch/PCL mass ratios and different nano TiO_(2) contents were characterized to explore the optimal blend ratio.Starch/PCL with different mass ratios were mixed,a certain amount of glycerin was added as plasticizer,and nano TiO_(2) with different contents was added as antibacterial agent,then fused and hot-pressed.The properties of the blends were characterized by mechanics,infrared,ultraviolet,SEM,DSC and water contact angle.The results showed that with the increase of PCL content,the breaking elongation of the blends decreased firstly and then increased,while the tensile strength increased gradually.When the mass fraction of PCL was 100%,the tensile strength of the blends increased 104% compared with that without the addition of PCL.The shielding effect of the blends on UV light was enhanced,and the water contact angle decreased from 78.2°to 53.3°.DSC showed that when the ratio of starch was relatively large,the crystallinity of the whole system was low,but the crystallization rate of PCL was accelerated.The addition of TiO_(2) did not cause chemical changes in the system,and had no significant effect on the tensile strength of the blends.The breaking elongation increased first and then decreased,and the maximum value was 51.69% when the mass fraction of TiO_(2) was 0.9%.The addition of TiO_(2) improved the UV barrier effect,but had little influence on the water contact angle of the blends.The antibacterial experiment results showed that TiO_(2) endowed the blends with a certain antibacterial ability,and with the increase of TiO_(2) content,the antibacterial performance becomes stronger.When the mass fraction of PCL was 100%,that is,the mass ratio of starch to PCL was 1:1,modified nano TiO_(2) with the mass fraction of 0.9% was added,and the blends obtained had relatively better properties,which provided reference for the preparation of degradable antibacterial packaging materials.