Combined effects of cellulose nanocrystals and silver nanoparticles on the barrier and migration properties of PLA nano-biocomposites

Poly(lactic acid) (PLA)-based high performance nano-biocomposites were prepared to be used in active food packaging. Pristine (CNC) and surfactant modified cellulose nanocrystals (s-CNC) with silver (Ag) nanoparticles were used as the matrix modifiers. Binary and ternary systems were prepared. Morphological investigations revealed the good distribution of silver nanoparticles in PLA ternary systems. The combination of s-CNC and Ag nanoparticles increased the barrier effect of the produced films while the results of overall migration for the PLA nano-biocomposites revealed that none of the samples exceeded the overall migration limit, since results were well below 60 mg kg−1 of simulant.

El plano geométrico de Crevillent: un pla urbanístic de sanejament i reforma interior de José Guardiola Picó el 1877

El present article analitza i situa en el context l’expedient urbanístic sobre la reforma interior del nucli urbà de Crevillent que l’ajuntament d’aquesta ciutat intentà dur a terme en l’últim quart del segle xix i que, en part, constitueix el plànol geomètric parcial d’aquesta vila. Es tracta d’un expedient municipal en què se succeeixen les actes del consistori per a la seua tramitació administrativa (entre 1876 i 1878) i en què s’intercala el projecte urbà de reforma interior, que consta de tres documents (memòria i dos planols: geomètric i de perfils), firmats el 12 de gener de 1877 per l’arquitecte José Guardiola y Picó (1836-1909), i que es tanca amb un plànol solt del 9 de gener de 1884 de firma no molt llegible.

Processing and characterization of plasticized PLA/PHB blends for biodegradable multiphase systems

Blends of poly(lactic acid) (PLA) and poly(3-hydroxybutyrate) (PHB) plasticized with a lactic acid oligomer (OLA) added at three different concentrations (15, 20 and 30 wt% by weight), were prepared by an optimized extrusion process to improve the processability and mechanical properties of these biopolymers for flexible film manufacturing. Morphological, chemical, thermal, mechanical, barrier and migration properties were investigated and formulations with desired performance in eco-friendly films were selected. The efficiency of OLA as plasticizer for PLA_PHB blends was demonstrated by the significant decrease of their glass transition temperatures and a considerable improvement of their ductile properties. The measured improvements in the barrier properties are related to the higher crystallinity of the plasticized PLA_PHB blends, while the overall migration test underlined that all the proposed formulations maintained migration levels below admitted levels. The PLA_PHB blend with 30 wt% OLA was selected as the optimum formulation for food packaging, since it offered the best compromise between ductility and oxygen and water vapor barrier properties with practically no migration.

El Pla Valencià del Llibre i la Lectura. Accions recomanades

Informe-resum dels continguts del II Simposi sobre la lectura, el llibre, les biblioteques i l’escola. El Pla Valencià de Foment del Llibre i la Lectura (PVFLL): Línies d’acció. Descripció de les accions que cal realitzar per a la implantació del Pla Valencià de Foment de la Lectura i el Llibre, detecció de les necessitats informatives i els primers passos que cal seguir.