Fabrication and Characterization of Novel Pla/Tpee Blends, Nanocomposites and Foams - Effects of Tpee Hard/Soft Segment Ratio and Type of Nanofillers

Biopolymers have attracted much attention during the past decades due to their eco-friendly characteristic. However, the disadvantages including narrow processing window, low heat resistance, and low strength, limit their applications. To improve the properties of biopolymers, the development of so-called “bionanocomposites” is one of the feasible ways. If the bionanocomposite foams could be further achieved through supercritical CO2 foaming process, the versatility of biopolymers can be extended. Poly(lactic acid) (PLA), possessing biomass/biodegradable character, is one of the most used biopolymers and shows great potential in replacing commodity polymers for certain applications. Thermoplastic poly(ether ester) elastomers (TPEE) show superior heat/chemical/oil resistance and excellent ductility. Its properties are controlled by the type and ratio of hard/soft segments. The blend of PLA with TPEE is less investigated, and it is anticipated that TPEE can enhance the heat resistance of PLA. According to the literature, the blend-based bionanocomposites are expected to achieve better performance compared with the neat components and blends. In this 3-year project, the PLA/TPEE blends, blend-based nanocomposites and their foams will be prepared through melt-mixing and scCO2 foaming processes. The studies on the relation between phase morphology/(cell)structure and properties of prepared blends/nanocomposites/foams will be highlighted. In the first year, PLA/TPEE blends (with different compatibilizers and hard/soft segment ratios of TPEE) of different compositions will be investigated and the results will be discussed. In the second year, the selected blends will be used to prepare the ternary PLA/TPEE blend-based nanocomposites (with a proper compatibilizer) for characterizations. The nanoCB, CNT and GNP will serve as nanofillers. Special attentions will pay to the selective localization of nanofillers and the mechanism of (double) percolation formation. In the third year, the selected blends and nanocomposites will be foamed by scCO2 under various conditions. The effects of foaming condition, nanofillers’ addition and blend composition on the structure and properties of resultant blends-nanocomposites/foams will be investigated and discussed. The instruments/equipments that will be employed for this project include: internal mixer/twin screw extruder, FESEM, TEM, DSC, TGA, PLM, WAXD, FTIR, DMA, rheometer, density/resistivity/dielectric meters etc.* nanoCB: nano carbon black; CNT: multi-walled carbon nanotube; GNP: graphene nanoplatelet

Project ID:PB10907-3543
External Project ID:MOST109-2221-E182-056-MY3