INVESTIGADORES
ARANGUREN mirta Ines
congresos y reuniones científicas
Título:
Biodegradable films from grafting of modified PLA onto starch nanocrystals
Autor/es:
N. GARCÍA; M. LAMANNA; N. D´ACCORSO; A. DUFRESNE; M. I. ARANGUREN; S. GOYANES
Lugar:
no consigna
Reunión:
Congreso; 3rd International Conference on Biodegradable and Biobased Polymers (BIOPOL-2011); 2011
Resumen:
The lack and the high costs of fossil resources have generated numerous initiatives aimed at replacing these sources with renewable ones. As polylactic acid (PLA) is a biodegradable, thermoplastic polymer, it is an ideal candidate to replace oil derivatives. On the other hand, starch is a cheap, abundant, renewable and biodegradable biopolymer, and then it is also a viable alternative1. In previous works, the production and characterization of starch nanoparticles was reported as being an interesting reinforcing agent2. Starch-PLA composites seem to be the most promising combination for starch-based packaging, but PLA and starch are thermodynamically immiscible3. In this work we propose a strategic synthetic pathway for modifying PLA to allow an appropriate grafting of PLA onto the surface of starch nanocrystals. PLA (pellets of 90% L-LA, 10% D-LA; Mn= 49860 determined by SEC) was subjected to a two-step reaction. The first step was carried out to protect the PLA hydroxyl groups with benzoyl chloride and a new material was obtained (PLABz). The second one was performed to activate the terminal carboxylic acid by treatment with thionyl chloride (PLAM). Then, PLAM was grafted onto the starch nanocrystal. The evolution of the reactions was studied by infrared spectroscopy, which confirmed the success of each step. The grafting efficiency was investigated by TGA, FTIR and DSC.