Crystallization kinetics of poly (butylene adipate terephthalate) in biocomposite with coconut fiber

Abstract

The melt crystallization characteristics of a compound of coconut lignocellulosic fibers dispersed in poly(butylene adipate terephthalate) (PBAT), a fully biodegradable copolyester matrix, was studied by differential scanning calorimetry (DSC). PBAT/coconut fiber compounds with 10% and 20% filler content were prepared in a laboratory internal mixer; torque rheometry showed negligible degradation during processing. Nonisothermal melt crystallization of the matrix was thoroughly studied by DSC in 10% compounds at cooling rates between 2 and 32°C/min, and quantitative information was provided on crystallization temperatures and rates, as well as the crystallinity developed, which turned out to be higher than expected at the high cooling rates. Crystallization kinetic results were correlated using classical macrokinetic Pseudo-Avrami, Ozawa, and Mo models, in order to obtain quantitative analytical expressions appropriate for processing applications. Pseudo-Avrami and Mo models were found to represent well the experimental data. A detailed analysis of the model fitting is presented, in order to assess the expected uncertainties. Despite its failings at the onset and end of the crystallization process, Mo model is recommended as best overall empirical correlation of the experimental data for the intended purpose.

Curcumin Incorporated Poly(Butylene Adipate-co-Terephthalate) Film with Improved Water Vapor Barrier and Antioxidant Properties

“…The melt-crystallization of the film samples was evaluated using a differential scanning calorimeter (DSCQ100, TA Instruments, New Castle, DE, USA), and the transition temperature was calculated from the DSC thermogram following the method of Sousa et al [ 41 ].…”

Rheological, thermal and mechanical characterization of PBAT/PCL/Stearates blends

“…Where Z* is the torque adjusted to the reference temperature T* (200ºC). β is the exponential temperature coefficient of the material which was determined to be β0.017°C -1 for PCL β0.025°C -1 for PBAT and β0.014 °C-1 for the PBAT/PCL blends, regardless of composition (Sousa et al, 2018;Reul et al, 2018;Sousa et al, 2016).…”

“…where RZ and RM are, respectively, the rates of change of the adjusted torque and the weight average molar mass of the material (Canedo, 2017) and n is the pseudoplasticity index of the material which for PCL, PBAT and the PBAT/PCL blends were determined to be 0.94; 0.60 and 0.59, respectively (Sousa et al, 2018;Reul et al, 2018;Sousa et al, 2016).…”

Avaliação das potencialidades dos extratos vegetais de jurema preta (Mimosa tenuiflora) e cajueiro (Anacardium occidentale L.) para uso em embalagens ativas antimicrobianas e antioxidantes

“…As propriedades mecânicas e físicas estão relacionadas com as unidades aromáticas e a biodegradabilidade às unidades alifáticas. O PBAT pode ser aplicado na produção de embalagens de alimentos, sacos plásticos compostáveis para jardinagem e no uso agrícola, além de seu uso em revestimentos resistentes à água [10].…”