Influence of clay surfactants polarity on the crystallization and rheological behavior of nanocomposites of PDLLA

Autor(es)

Brito Ramos, Renata Brandao ^[1] ; Sinohara Souza, Patricia Moraes ^[1] ; Morales, Ana Rita ^[1]

Afiliação do(s) autor(es)

^[1] Univ Estadual Campinas, UNICAMP, Dept Engn Mat & Bioproce, Fac Engn Quim, Campinas, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: MATERIALS RESEARCH-IBERO-AMERICAN JOURNAL OF MATERIALS; v. 21, n. 6 2018.
• Citações Web of Science: 0

Resumo

The effect of clay hydrophobicity on the cold crystallization and rheological properties of nanocomposites of poly(D,L-lactic acid) (PDLLA) was investigated. Crystallization was evaluated by DSC for isothermal and non-isothermal conditions. The clay modified with a hydrophilic surfactant acts as a nucleating agent, while the clay modified with a hydrophobic surfactant acts in an opposite way. The Avrami and Ozawa parameters showed a three-dimensional spherulitic growth for all samples and the activation energy increased for the hydrophobic clay and decrease for the hydrophilic one. The equilibrium melting point for the PDLLA was found at 161 degrees C, being slightly altered as function of the surfactant polarity. The rheological behavior was investigated in terms of Isothermal Flow-Induced Crystallization and Structural Recovery. The hydrophobic clay showed to reduce the mobility of chains and retard the chain relaxation, which is attributed to the formation of a network, while the hydrophilic clay increased the chain mobility. (AU)

• Processo FAPESP: 12/00227-2 - Estudo de nanocompósitos de PLA/argilas organofílicas: caracterização, biodegradação e efeitos genotóxicos e mutagênicos
• Beneficiário: Ana Rita Morales
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 11/14250-3 - Estudo da influência de argilas organofílicas no processo de biodegradação de nanocompósitos de PLA e seus efeitos genotóxicos e mutagênicos.
• Beneficiário: Patrícia Moraes Sinohara Souza
• Modalidade de apoio: Bolsas no Brasil - Mestrado