Indução da cristalinidade de poli(ácido lático) e sua influência no processo de biodegradação em solo simulado

• Autor(a) principal: Correia, Thiago Ramos
• Data de Publicação: 2016
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/15842
• topic: PLA; crystallinity; biodegradability; PLA; cristalinidade; biodegradabilidade.; CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA::QUIMICA ORGANICA::POLIMEROS E COLOIDES

So much has been discussed about the problem of irregular disposal of plastic materials. As alternatives to decrease these problems, the study of biodegradable polymers has intensified every year. The poly (lactic acid) (PLA) is a biodegradable polymer which has a great versatility and the study of their crystallinity aims to find better properties to increase the number of its possible applications. In this work, the crystallinity of the poly (lactic acid) was induced by adding nucleating agent and annealing. Was verified and the influence of the crystallinity content at their biodegradability. Biodegradability tests were conducted in simulated soil following the ASTM G160-03 and G160-12 ASTM and were evaluated the loss of mass, surface morphology of the samples by techniques of optical microscopy (OM) and scanning electron microscopy (SEM) , their thermal stability by thermogravimetric analysis (TGA) and changes in crystallinity by differential scanning calorimetry (DSC), the chemical modification in structure of the compound by infrared spectroscopy (FT-IR) and monitoring the molar mass change of the polymer by gel permeation chromatography (GPC) over time subject to soil burial. Was observed that treatments for crystallinity induction on PLA were effective. The polymer suffers from microbial attack in simulated soil as evidenced by the appearance of surface erosion and microorganisms adhesion by OM and SEM techniques, the appearance of the carboxylic acid carbonyl bands by FTIR technique, and by changes in the thermal properties by DSC and TGA after the biodegradation test