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本研究通过溶胶-凝胶法制备出纳米二氧化钛(TiO_2),并采用硅烷偶联剂KH-550对其进行表面改性,减缓纳米TiO_2的团聚,通过溶液共混法制备出聚左旋乳酸(PLLA)/TiO_2复合薄膜。采用DSC、SEM、TG、紫外光谱和DMA等系统研究了TiO_2及其PLLA复合物的结构和性能。结果表明:TiO_2经过表面接枝改性后,平均粒径由533nm降低为346nm,其接枝率为4.2%(wt,质量分数,下同)。未改性的TiO_2在PLLA中分散性差,易团聚,改性后TiO_2在含量低于1.5%的条件下,能在PLLA中分散。TiO_2的加入提高了PLLA复合物的热稳定性、抗紫外性能和储能模量,对PLLA的结晶性能影响较小。
In this study, nano-TiO 2 was prepared by sol-gel method and its surface was modified by silane coupling agent KH-550 to slow down the agglomeration of nano-TiO 2. Poly-L-lactic acid ) / TiO 2 composite film. The structure and properties of TiO_2 and PLLA composites were studied by DSC, SEM, TG, UV spectroscopy and DMA. The results showed that the average particle size of TiO 2 was reduced from 533 nm to 346 nm after grafting modification. The grafting rate of TiO 2 was 4.2% (wt, mass fraction). The unmodified TiO 2 has poor dispersibility in PLLA and easy to agglomerate. After being modified, TiO 2 can be dispersed in PLLA under the condition of less than 1.5%. The addition of TiO_2 increased the thermal stability, UV resistance and storage modulus of PLLA composites, and had little effect on the crystallinity of PLLA.