Non-Isothermal Crystallization Kinetic of Polyethylene/Carbon Nanotubes Nanocomposites Using an Isoconversional Method

• Published in: Journal of composites science Vol. 3; no. 1; p. 21
• Main Authors: Beatriz Rossi Canuto de Menezes, Tiago Moreira Bastos Campos, Thais Larissa do Amaral Montanheiro, Renata Guimarães Ribas, Luciana de Simone Cividanes, Gilmar Patrocínio Thim
• Format: Journal Article
• Language: English
• Published: MDPI AG 2019
• Subjects: carbon nanotubes; crystallization kinetic; functionalization; high-density polyethylene; isoconversional method
• ISSN: 2504-477X
• DOI: 10.3390/jcs3010021

Behavior studies of thermoplastic polymers during non-isothermal crystallization are extremely important since most of their properties are influenced by degree of crystallinity and the crystallization process. In general, an approach based on a model-fitting method is used to perform crystallization kinetic studies. Due to their inability to uniquely determine the reaction mode, many studies have used the isoconversional method, where it is not necessary to assume a crystallization model to obtain the kinetic parameters. Therefore, in this work, the influence of acid and octadecylamine functionalized carbon nanotubes (CNTs) in the crystallization kinetic of polyethylene (PE) was studied using an isoconversional method with differential scanning calorimetry (DSC) and polarized optical microscopy (POM). The kinetic parameters and the crystallization model were determined. The incorporation of functionalized and non-functionalized CNTs into PE did not change the Johnson-Mehl-Avrami crystallization model. However, the CNTs increased the crystallization temperature and reduced the activation energy for crystallization. In addition, the Avrami coefficient values were lower for the nanocomposites when compared to pure PE. The incorporation of CNTs accelerated the crystallization of PE, reducing the crystallite sizes and modifying their morphology.