Andrea Lazzeri

Effect of different nucleating agent on crystallinity and properties of polylactic acid

Polylactide (PLA) is a promising biobased, compostable polymer suitable for replacing petro-derived polymer not just in single use applications but also for durable equipment requiring more demanding technical performances, in particular in terms of mechanical properties and stability. Consequently a better knowledge of the crystallization behavior of PLA and its effects on the mechanical properties is crucial in order to extend its industrial applications, and even for optimization of polymeric matrices to be further used for biocomposite or active packaging production. In the present study, different nucleating agents have been added to PLA during processing by extrusion and injection molding, to tune the percentage of crystallinity, and modulate the mechanical properties. Boron Nitride and nano fillers (Talc, Calcium Carbonate) have been tested as nucleating agents in variable amount. All the additives investigated evidenced a positive effect on increasing in the degree of crystallinity of PLA and, consequently an improvement of its mechanical properties and widening of potential performance.Polylactide (PLA) is a promising biobased, compostable polymer suitable for replacing petro-derived polymer not just in single use applications but also for durable equipment requiring more demanding technical performances, in particular in terms of mechanical properties and stability. Consequently a better knowledge of the crystallization behavior of PLA and its effects on the mechanical properties is crucial in order to extend its industrial applications, and even for optimization of polymeric matrices to be further used for biocomposite or active packaging production. In the present study, different nucleating agents have been added to PLA during processing by extrusion and injection molding, to tune the percentage of crystallinity, and modulate the mechanical properties. Boron Nitride and nano fillers (Talc, Calcium Carbonate) have been tested as nucleating agents in variable amount. All the additives investigated evidenced a positive effect on increasing in the degree of crystallinity of PLA and, con...

New eco-composites based on polyhydroxyalkanoates (PHA) for marine applications

B polymers have attracted increasing attention over the last two decades, predominantly due to their environmental friendly nature and no dependence on petroleum resources. This type of polymers has got a growing consideration which has been so far focused specifically on starch based products, PLA (Polylactic acid), PHA (Polyhydroxylalkanoates) in particular PHB (Poly hydroxyl butyrate), cellulose derived plastics, etc. The production of these materials is based on renewable agricultural and biomass feedstocks. The degradability of bio-based materials not just in compost but also in different natural environments is an important property for sustainability and reduction of plastic pollution. In this work, blends of PHA and PHB with Posidonia Oceanica fibres were investigated to assess the feasibility of producing materials biodegradable in marine environment, varying the fiber percentage from 10 to 30 wt%. The chemical composition of the Posidonia O. fiber is similar to that of other lignocellulosic materials. It consists mainly of cellulose, hemicellulose, and lignin. Thermal, rheological, mechanical and morphological characterization of the developed PHA/PHB-fibre blends has been conducted in order to investigate the effect of the fibres on their processability and tensile properties. Biodegradability of the produced composites has been investigated in sea water in view of their use in marine environment.