Reactive Compatibilization of Polylactide/Polypropylene Blends

Abstract

Polylactide (PLA) was melt blended with either polypropylene (PP) or a polypropylene based elastomer (PBE, Vistamaxx) in an effort to improve its mechanical properties. An ethylene−glycidyl methacrylate−methyl acrylate terpolymer (PEGMMA, Lotader) was utilized as compatibilizer through coupling to the end groups of PLA. Graft copolymers formed enhanced the adhesion between PLA and polyolefin phases and lowered the interfacial tension. The morphological, mechanical, and rheological properties of the PLA/polyolefin compatibilized blends were investigated, and the blends exhibited substantial improvement in elongation at break and tensile toughness as compared to the corresponding binary blends. The remarkable efficacy of PEGMMA as a reactive compatibilizing agent allows the bridging of two immiscible but important classes of thermoplastics, polylactide and polypropylene, and the production of ductile PLA/PP blend materials.

Development of biodegradable PLA/PBT nanoblends

“…From these images, it is possible to observe a significant reduction in the size of the dispersed particles for the compatibilized blends. 5,28 Considering for the blends studied that a constant shear rate was imposed during the melt blending and analyzing Figure 6, it is possible to observe a significant reduction in the size of the dispersed particles for the compatibilized blends. 9,10,27,28 The role of the compatibilizer in the blend is to reduce interfacial tension and aid in dispersion and stabilization of the system by preventing the coalescence of the particles.…”

“…[1][2][3] They have attracted great interest as a substitute for traditional petroleumbased thermoplastics, because they have the possibility of solving environmental problems. [1][2][3]5 It is widely used for biomedical and packing applications because of its excellent optical properties and very low toxicity. However, it is a relatively brittle thermoplastic and has a low crystallization rate.…”

“…However, it is a relatively brittle thermoplastic and has a low crystallization rate. 3,[5][6][7] The successful development of immiscible blends is strongly dependent on two important parameters: adjustment of the interface interactions between the two constituent materials and obtaining an optimized phase morphology. 1,3 Blending of PLA with an immiscible component has been reported in order to obtain improved toughness and expand PLA use and applications.…”

“…[1][2][3]5 It is widely used for biomedical and packing applications because of its excellent optical properties and very low toxicity. 5,8 Singular properties can be achieved in immiscible polymer blends when the particles of the dispersed phase have dimensions at nanometer sizes, called nanoblends. 3,[5][6][7] The successful development of immiscible blends is strongly dependent on two important parameters: adjustment of the interface interactions between the two constituent materials and obtaining an optimized phase morphology.…”

“…1 Glycidyl methacrylate (GMA) grafted copolymers are often used in polyester blends as reactive compatibilizers. 5 The aim of this work was to analyze the influence of PBT and of a functionalized copolymer on the morphology and mechanical and thermal behavior of the PLA matrix, as well as to study the influence of PBT on the crystallization rate of PLA. Figure 2 identifies two main reactions that can occur between the epoxide functional groups contained in GMA and the polyester end groups.…”