scholarly journals Impact of Enzymatic Degradation on the Material Properties of Poly(Ethylene Terephthalate)

Polymers ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 3885
Author(s):  
Teresa Menzel ◽  
Sebastian Weigert ◽  
Andreas Gagsteiger ◽  
Yannik Eich ◽  
Sebastian Sittl ◽  
...  

With macroscopic litter and its degradation into secondary microplastic as a major source of environmental pollution, one key challenge is understanding the pathways from macro- to microplastic by abiotic and biotic environmental impact. So far, little is known about the impact of biota on material properties. This study focuses on recycled, bottle-grade poly(ethylene terephthalate) (r-PET) and the degrading enzyme PETase from Ideonella sakaiensis. Compact tension (CT) specimens were incubated in an enzymatic solution and thermally and mechanically characterized. A time-dependent study up to 96 h revealed the formation of steadily growing colloidal structures. After 96 h incubation, high amounts of BHET dimer were found in a near-surface layer, affecting crack propagation and leading to faster material failure. The results of this pilot study show that enzymatic activity accelerates embrittlement and favors fragmentation. We conclude that PET-degrading enzymes must be viewed as a potentially relevant acceleration factor in macroplastic degradation.

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 248 ◽  
Author(s):  
Dashan Mi ◽  
Yingxiong Wang ◽  
Maja Kuzmanovic ◽  
Laurens Delva ◽  
Yixin Jiang ◽  
...  

In situ microfibrillation and multiflow vibrate injection molding (MFVIM) technologies were combined to control the phase morphology of blended polypropylene (PP) and poly(ethylene terephthalate) (PET), wherein PP is the majority phase. Four kinds of phase structures were formed using different processing methods. As the PET content changes, the best choice of phase structure also changes. When the PP matrix is unoriented, oriented microfibrillar PET can increase the mechanical properties at an appropriate PET content. However, if the PP matrix is an oriented structure (shish-kebab), only the use of unoriented spherical PET can significantly improve the impact strength. Besides this, the compatibilizer polyolefin grafted maleic anhydride (POE-g-MA) can cover the PET in either spherical or microfibrillar shape to form a core–shell structure, which tends to improve both the yield and impact strength. We focused on the influence of all composing aspects—fibrillation of the dispersed PET, PP matrix crystalline morphology, and compatibilized interface—on the mechanical properties of PP/PET blends as well as potential synergies between these components. Overall, we provided a theoretical basis for the mechanical recycling of immiscible blends.


2015 ◽  
Vol 735 ◽  
pp. 8-12
Author(s):  
Nurul Ain Jamaludin ◽  
Azman Hassan ◽  
Norhayani Othman ◽  
Mohammad Jawaid

The objective of this study is to investigate the effect of halloysite nanotubes (HNTs) loading on mechanical and thermal properties of poly(ethylene terephthalate)/polycarbonate (PET/PC) nanocomposites. Nanocomposites containing 70PET/30PC and 2-8 phr HNTs were prepared by twin screw extruder followed by injection moulding. As the percentage of HNTs increased, the flexural modulus increased. However, the flexural strength decreased with increasing HNTs content. The impact strength also decreased when HNTs increased. Thermogravimetry analysis of PET/PC/HNTs nanocomposites showed higher thermal stability at high HNTs content. However, on further addition of HNTs up to 8 phr, thermal stability of the nanocomposites decreased due to the poor dispersion of HNTs.


2005 ◽  
Vol 26 (17) ◽  
pp. 1400-1405 ◽  
Author(s):  
Rolf-Joachim Müller ◽  
Hedwig Schrader ◽  
Jörn Profe ◽  
Karolin Dresler ◽  
Wolf-Dieter Deckwer

2014 ◽  
Vol 695 ◽  
pp. 131-134 ◽  
Author(s):  
Mohd Nazry Salleh ◽  
Ruey Shan Chen ◽  
Mohd Hafizuddin Ab Ghani ◽  
Farizul Hafiz Kasim ◽  
Ahmad Sahrim

Polymer blends based on recycled high density polyethylene (rHDPE) and recycled poly (ethylene terephthalate) (rPET) with two types of ethylene-glycidyl methacrylate copolymer (E-GMA), Lotader AX8840 and Lotader AX8900 as compatibilizer were produced in a co-rotating twin screw extruder. The effects of adding rPET content on the impact properties of rHDPE-rich blends were also investigated. The result showed an enhancement of about 80-270% in impact properties as compared to those of the Lotader AX8900. The impact strength also showed a decreasing trend as the rPET content was increased. The addition of E-GMA to the rHDPE/rPET blends was found to recover the blend toughness as well as improving the compatibility between HDPE and PET. In this study, the highest result was obtained for the rHDPE/rPET blends using Lotader AX8840 composition with 7.5% E-GMA content. FTIR analysis of the compatibilized blends confirmed the chemical interaction and improved interfacial bonding between the two phases.


Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2499
Author(s):  
Alena Opálková Šišková ◽  
Katarína Mosnáčková ◽  
Jakub Hrůza ◽  
Jaroslava Frajová ◽  
Andrej Opálek ◽  
...  

In this study, fibrous membranes from recycled-poly(ethylene terephthalate)/silk fibroin (r-PSF) were prepared by electrospinning for filtration applications. The effect of silk fibroin on morphology, fibers diameters, pores size, wettability, chemical structure, thermo-mechanical properties, filtration efficiency, filtration performance, and comfort properties such as air and water vapor permeability was investigated. The filtration efficiency (FE) and quality factor (Qf), which represents filtration performance, were calculated from penetration through the membranes using aerosol particles ranging from 120 nm to 2.46 μm. The fiber diameter influenced both FE and Qf. However, the basis weight of the membranes has an effect, especially on the FE. The prepared membranes were classified according to EN149, and the most effective was assigned to the class FFP1 and according to EN1822 to the class H13. The impact of silk fibroin on the air permeability was assessed. Furthermore, the antibacterial activity against bacteria S. aureus and E. coli and biocompatibility were evaluated. It is discussed that antibacterial activity depends not only on the type of used materials but also on fibrous membranes’ surface wettability. In vitro biocompatibility of the selected samples was studied, and it was proven to be of the non-cytotoxic effect of the keratinocytes (HaCaT) after 48 h of incubation.


Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1755
Author(s):  
Wieslaw Lyskawinski ◽  
Mariusz Baranski ◽  
Cezary Jedryczka ◽  
Jacek Mikolajewicz ◽  
Roman Regulski ◽  
...  

The aim of this study was to investigate and analyze the impact of selected parameters during the tribocharging process of shredded poly(ethylene terephthalate) (PET) and high-density polyethylene (PE-HD) plastics on accumulated electric charge and electrostatic separation effectiveness. The accumulation of electric charge on surfaces of polymer particles as a result of their circular motion forced by the airflow cyclone container was investigated. The impact of the container material, time of tribocharging and the airflow intensity were experimentally examined. A container in which the particles of the considered polymers are electrified with opposite charges was selected. A high ability to accumulate surface charge on small particles of both polymers was demonstrated. The electrified mixed PET/PE-HD was subjected to a separation process. An electrostatic separator designed and constructed by the authors was used for to the separation. In turn, to assess the effectiveness of this separation, a dedicated vision system was used. Based on the result of the carried out tests, it has been assumed that the proposed approach’s effectiveness has been demonstrated by means of empirical validation.


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