Andreas Himmelsbach, Yavuz Akdevelioglu, Mohammadreza Nofar, Holger Ruckdäschel
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引用次数: 0
Abstract
In this study, the influence of the chain extender (CE) and the blend ratio on the bead foam extrusion of rPET/PBT is investigated. The shape and density of the bead foams were analyzed during extrusion using a camera scanner while the morphology of the foam was investigated using scanning electron microscopy (SEM). Melt strength and thermal behavior were also investigated with Rheotens and differential scanning calorimetry (DSC), respectively. Both chain extender and blend ratio had pronounced effect on the foaming behavior. Significant improvements were observed up to 0.8 wt.-% CE in rPET50PBT50, which achieved an average cell size of 107 ± 17 μm and a density of 182 kg/m³, representing a weight reduction of 86.4% compared to the bulk material. In addition, rPET40PBT60 with 0.8 wt.-% CE gave an average cell size of 108 ± 23 μm and a foam density of 170 kg/m³, with a comparable cell size distribution. After CE modification, the melt strength of rPET-dominant blends obtained higher values but a strong decrease in elongation was observed. In contrast, the CE-modified rPET40PBT60 and rPET30PBT70 blends exhibited much higher elongation with a moderate increase in melt strength which resulted in better bead and foam morphologies. DSC analysis revealed lowest crystallization temperature in rPET50PBT50 with deviations shifting towards higher temperatures. All blends except rPET70PBT30 shows double melting peak formation, with higher rPET formulations also exhibiting cold crystallization. These findings provide crucial insight for development of rPET/PBT foams by controlling the blend and CE composition, which is critical for achieving temperature-resistant bead foams with improved structural integrity.
期刊介绍：
The Journal of Polymers and the Environment fills the need for an international forum in this diverse and rapidly expanding field. The journal serves a crucial role for the publication of information from a wide range of disciplines and is a central outlet for the publication of high-quality peer-reviewed original papers, review articles and short communications. The journal is intentionally interdisciplinary in regard to contributions and covers the following subjects - polymers, environmentally degradable polymers, and degradation pathways: biological, photochemical, oxidative and hydrolytic; new environmental materials: derived by chemical and biosynthetic routes; environmental blends and composites; developments in processing and reactive processing of environmental polymers; characterization of environmental materials: mechanical, physical, thermal, rheological, morphological, and others; recyclable polymers and plastics recycling environmental testing: in-laboratory simulations, outdoor exposures, and standardization of methodologies; environmental fate: end products and intermediates of biodegradation; microbiology and enzymology of polymer biodegradation; solid-waste management and public legislation specific to environmental polymers; and other related topics.
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