关键词: 茶粉, 聚乳酸, 生物质, 复合材料, 增韧, 增塑剂

Abstract: In order to make high-valued use of the tea waste,we prepared the toughened tea dust/poly(lactic acid)(TD/PLA)composites with a melt blending method,and using glycerol(GL),polyethylene glycol,epoxidized soybean oil(ESO)and tributyl acetylcitrate(ATBC)as plasticizers to improve the ductility of TD/PLA Fourier infrared absorption spectroscopy(FTIR),thermogravimetric analysis(TGA),torque rheometer(TR),scanning electronic microscopy(SEM)and mechanical test were adopted to study the effects of plasticizers on the structure and performance of TD/PLA blends. The results showed that the addition of GL,PEG,ESO or ATBC resulted in an improvement in the processing rheological properties and toughness,but a decrease in mechanical strength. The TD/PLA composites showed best toughness by adding ESO and the corresponding elongation at break and notched impact strength increased by 154.23% and 65.53%,respectively. The TD/PLA composites showed the best mechanical strength with ATBC and the worst ductility plasticized with GL. The interaction between ESO or ATBC and PLA was confirmed by a small shift of C-O stretching peak in the IR spectrum. The water adsorption of the composites decreased with the addition of ESO or ATBC but increased with PEG or GL. The vicat softening point and thermal stability of the TD/PLA composites were improved in the presence of ESO. The fracture surface SEM images of the composites indicated that ESO was well dispersed in PLA matrix and the fracture surface morphology was much rough,while there was distinct phase separation in the fracture surface of TD/PLA/GL composites.

Key words: tea dust, poly(lactic acid), biomass, composites, toughening, plasticizer