Avaliação das propriedades mecânicas e térmicas do poli(ácido lático) com a adição de Therpol® como modificador de impacto

Abstract

The use of biodegradable polymers is seen as one of the many strategies to minimize the environmental impact generated by the improper disposal of plastic waste. Poly(lactic acid) (PLA) is a biodegradable polymer with high mechanical strength and high modulus of elasticity. Its use is limited due to its high brittleness and low toughness. Therpol® is an elastomer from the company Proquitec, composed of natural rubber and additive, which works as an impact modifier in polymers. Impact modifiers are additives capable of increasing fracture toughness, enabling changes in both mechanical and thermal properties. Thus, this study aims to evaluate the effect of the additive Therpol® on the mechanical and thermal behavior of PLA. The Therpol® content in the PLA blends was 3, 5 and 10% by weight, being prepared by extrusion and their test specimens by pressing. These samples were characterized by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR) and tensile testing. The effect of the impact modifier on the brittleness and thermal properties of PLA was verified. In the characterization results of the PLA/Therpol blends, no improvements were observed in the flexibility and thermal properties of the polymer, without chemical change, since there was not a sufficient degree of mixing in the blends.