Ricerc@Sapienza

The mechanical behavior of materials endowed with specific microstructure can be properly described through a continuum model suitably derived by means of a multiscale approach. In this field, the Cosserat model proved effective, with respect to Cauchy continua, especially in cases of heterogeneous materials made of particles of prominent size and/or anisotropic media (particle composites, masonry, etc.).

Tissue engineering is a highly interdisciplinary field of medicine aiming at regenerating damaged tissues by combining cells with porous scaffolds materials. Scaffolds are templates for tissue regeneration and should ensure suitable cell adhesion and mechanical stability throughout the application period. Chitosan (CS) is a biocompatible polymer highly investigated for scaffold preparation but suffers from poor mechanical strength.

In order to investigate the role of plant hybridization in barley on the overall thermomechanical performance of polymeric composites containing their by-products, straws from one self-pollinated (Quench) and two F1 hybrid lines of barley (Tatoo and Zoo) were collected and characterized from the chemical (FTIR), structural (XRD), thermal (TGA) and mechanical (tensile) point of view, and used as reinforcements in a commodity plastic, such as polypropylene.

Composites with high density polyethylene (HDPE) and poly(lactic) acid (PLA) matrix have been tested to analyze the effect of natural fillers (wood flour, recycled wastepaper and a mix of both fillers) and temperature on polymer degradation. Composting tests have been performed in both mesophilic (35 °C) and thermophilic (58 °C) conditions. Degradation development has been evaluated through mass variation, thermogravimetric analysis and differential scanning calorimetry. HDPE, as expected, did not display any relevant variation, confirming its stability under our composting conditions.

Blends based on high density polyethylene (HDPE) and poly(lactic) acid (PLA) with different ratios of both polymers were produced: a blend with equal amounts of HDPE and PLA, hence 50 wt.% each, proved to be a useful compromise, allowing a high amount of bio-derived charge without this being too detrimental for mechanical properties and considering its possibility to biodegradation behaviour in outdoor application.