Avaliação do efeito da incorporação de nanocomponente inorgânico pró-oxidante no processamento, propriedades e comportamento frente ao envelhecimento acelerado de blendas de polipropileno e poli(-hidroxibutirato)

Abstract

The generation of waste in the world has grown almost exponentially, and between different types of waste, the polymer has an important participation. Thus, it is estimated that by 2015 there will be no landfill sites available for these wastes. Polypropylene (PP) has an important role in waste management but polymer degradation is slow. There is a concern to develop advanced oxidation processes so that we can accelerate this degradation using a pro-oxidant additives. Poly (hydroxybutyrate) (PHB) is highly biodegradable, making it very attractive as a substitute for traditional polymers. PHB has physical and mechanical characteristics similar to those of PP, but has the disadvantages of cost and difficulty of processing. In this context, we aimed to evaluate the effect of incorporation of inorganic nanocomponents pro-oxidant in the processing, properties and behavior regarding the accelerated aging of blends of PP and PHB. To verify the modifications in the blends were produced specimens for mechanical characterization, morphological and thermal, and infrared spectroscopy (FTIR) and accelerated aging second specific standards. It was demonstrated the feasibility of processing blends of PP with 10% w/w of PHB by traditional processing methods. The addition of compatibilizer was effective in reducing the average size of the dispersed phase and enhance the adhesion between the phases. The incorporation of up to 3% TiO2 nanoparticles led to an increase in the average size of the dispersed phase, indicating its incorporation in the phases rich in PHB. The change following the addition of TiO2 nanoparticles allowed the incorporation of these nanocomponents guide for the PP-rich phase. The mechanical properties of the blends proved similar to those of pure PP, tending to increase in modulus and strength, and reduced the fracture strain to the incorporation of PHB and TiO2 nanoparticles in PP. The blends of PP / PHB produced are more thermally stable than PHB. The addition of TiO2 nanoparticles was effective to increase the thermal stability of the blends. FTIR and thermogravimetric analysis showed that blends containing TiO2 nanoparticles were more affected in its degradation accelerated aging tests than blends without the presence of nanocomponents. The extraction test showed the increased presence of leachable molecules with the addition of TiO2 and reduction of this presence with the addition of compatibilizer.