The Effect of Polystyrene on the Crystallization of Poly(3-hydroxybutyrate)

Renate Maria Ramos Wellen,Yêda Medeiros Bastos De Almeida,Camila Augusta Ventura Lima,Eduardo Luís Canedo,Marcelo Silveira Rabello,Inaldo Cesar Araújo Júnior

doi:10.1590/1516-1439.242213

Abstract

Mechanical properties, morphology and nonisothermal crystallization of poly(3-hydroxybutyrate) (PHB) and blends of PHB and polystyrene (PS) were studied by tensile tests, scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). A two-phase structure composed by a PHB matrix and nearly spherical particles of PS was clearly noticed in SEM images. The presence of small amounts (0.5% to 3%) of amorphous PS affected the crystallinity of PHB, being more evident when high cooling rates were applied. The kinetics of nonisothermal crystallization was modeled according to Ozawa equation. The dependence of Ozawa parameters on temperature followed the same trend for PHB and PHB/PS blends; model parameters were found to be lower for the blends than for the neat PHB.

Highlights

A current concern of the scientific community and the society in general is the environment preservation and other ecological issues
PHB/PS blends with PS content ranging between 0.5 and 3wt% were compounded in a Haake Rheomix 3000 internal mixer fitted with high-intensity (“roller” type) rotors, for 12 min at 180°C and 60 rpm; neat PHB was processed at same conditions to ensure the same thermal
Since PS is a fully amorphous polymer the melting and crystallization processes recorded by differential scanning calorimetry (DSC) were attributed to presence of PHB in the samples

Summary

Introduction

A current concern of the scientific community and the society in general is the environment preservation and other ecological issues Committed with this cause, polymer researchers have sought alternatives to deal with synthetic plastic waste by directing their research to the study of development and use of polymers obtained from renewable sources, such as bacterial fermentation and sugar cane. Polymer researchers have sought alternatives to deal with synthetic plastic waste by directing their research to the study of development and use of polymers obtained from renewable sources, such as bacterial fermentation and sugar cane Some of these biopolymers, like poly (3-hydroxybutyrate) (PHB), are semi crystalline, i.e., they have amorphous disordered phase, amorphous ordered phase and crystalline phase. On going research, intended on establishing its properties, and optimizing its processing conditions is reported in the literature[5,6,7]

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Conclusion