Ecocompatible, Biodegradable Polymers. Plastic Items. Preparation & Characterization.

The study of this thesis was focused on natural materials of marine origin such as algae or seaweeds and lignocellulosic materials such as sugar cane bagasse (SCB) and rice straw (RS). The aim was to make an improve for the mechanical properties of the polymer blending it with the selected natural fillers to obtain composites and objects that can be competitive with the conventional ones and so introduced on the market. This work was structured in three chapters, where the latter reports all the obtained results divided in six sections. In the first section, the polyhydroxyalkanoates (PHAs) production from olive oil mills wastewater, their characterization and Lyfe Cycle Assessment (LCA) were studied. For this purpose, a screening of the traditional methods and carbon source to obtain PHAs from biomasses, was conducted, in order to plan a POLYVER technology. The variables selected were four bacterial strains processed in a Pilot Aerobic Reactor (PAR), in a Small Aerobic Reactor (SAR) and in a Pilot Plant (PP) in accord to the LABOR (Rome) protocol. The PHAs were characterized by means of thermal analysis (TGA and DSC), gel permeation chromatography (GPC) and Fourier Transform Infrared Spectroscopy (FTIR). In the second section, the cellulose extracted from sugar cane bagasse and rice straw was modified by the acetylation process obtaining cellulose acetate. The starting raw materials were dried and submitted to a dewaxing process using a Kumagawa extractor and toluene/ethanol (2:1) as a solvent mixture. SCB and RS, before and after dewaxing, were characterized by means of scanning electron microscopy (SEM), TGA, DSC and FTIR. Some chemical procedures were used to isolate the material components (cellulose, alkaline peroxide soluble hemicellulose, alkaline peroxide soluble lignin, WSFR). The cellulose and its acetylated product that is cellulose acetate were characterized by means of SEM, TGA, DSC, FTIR and wide angle x-ray scattering (WAXS). The FTIR technique was used for the determination of the substitution degree (DS) of the acetylated product (DS=2.7). The third section comprises two series of experiments concerning the production of blends based on biodegradable polymers, natural and synthetic. Two different types of blends were produced: polylactic acid-Bionolle (PLABn) and cellulose acetate-polyhydroxybutirrate (CA/PHB) blends. The first type was obtained by compression moulding and the second was produced by film casting. PLABn blends were characterized by means of TGA, DSC and tensile test (Instron), while CA/PHB blends were characterized by means of SEM, TGA, DSC and wide angle x-ray scattering (WAXS). The fourth section analyzed the production and the characterization of composites based on biodegradable polymers and natural organic fillers. Some types of composites were produced using algae, ground rice and its by-products as natural fillers and PHB, PCL, hydrolene as biodegradable polymers by extrusion or compression moulding. These composites were evaluated for dimensional (ASTM distribution), morphological (SEM, FTIR), thermal (TGA, DSC) and mechanical properties. The obtained results showed that the ground rice improved the adhesion between the filler and the polymeric matrix. The mechanical properties of the Ulva family showed an increase for the Young Modulus and a decrease for the Elongation at Break and the Ultimate Tensile Strenght. The fifth and sixth sections reported the background for the foaming agents and the effervescent materials.