scholarly journals The Feasibility of Using the MFC Concept to Upcycle Mixed Recycled Plastics

2021 ◽  
Vol 13 (2) ◽  
pp. 689 ◽  
Author(s):  
Maja Kuzmanović ◽  
Laurens Delva ◽  
Ludwig Cardon ◽  
Kim Ragaert
Keyword(s):  
Cold Drawing ◽  
Polymer Waste ◽  
Poly Ethylene Terephthalate ◽  
Interesting Approach ◽  
Poly Ethylene ◽  
Recycled Plastics ◽  
Pet Film ◽  
Microfibrillar Composites ◽  
High Level ◽  
Mixed Bilayer

Several mixed recycled plastics, namely, mixed bilayer polypropylene/poly (ethylene terephthalate) (PP/PET) film, mixed polyolefins (MPO) and talc-filled PP were selected for this study and used as matrices for the preparation of microfibrillar composites (MFCs) with PET as reinforcement fibres. MFCs with recycled matrices were successfully prepared by a three-step processing (extrusion—cold drawing—injection moulding), although significant difficulties in processing were observed. Contrary to previous results with virgin PP, no outstanding mechanical properties were achieved; they showed little or almost no improvement compared to the properties of unreinforced recycled plastics. SEM characterisation showed a high level of PET fibre coalescence present in the MFC made from recycled PP/PET film, while in the other MFCs, a large heterogeneity of the microstructure was identified. Despite these disappointing results, the MFC concept remains an interesting approach for the upcycling of mixed polymer waste. However, the current study shows that the approach requires further in-depth investigations which consider various factors such as viscosity, heterogeneity, the presence of different additives and levels of degradation.

Constant-Temperature Embossing of Amorphous Poly(Ethylene Terephthalate) Films

2007 ◽  
Author(s):  
Donggang Yao ◽  
Pratapkumar Nagarajan ◽  
K. R. T. Ramasubramani
Keyword(s):  
Thermal Cycling ◽  
Amorphous Phase ◽  
Constant Temperature ◽  
Ethylene Terephthalate ◽  
Mold Temperature ◽  
Cycle Times ◽  
Poly Ethylene Terephthalate ◽  
Micro Features ◽  
Poly Ethylene ◽  
Pet Film

In the standard hot embossing process for thermoplastic polymers, thermal cycling is needed in order to soften and subsequently cool and solidify the polymer. This thermal cycling, however, not only results in long cycle times but also deteriorates the quality of embossed features. A new embossing method based on slowly crystallizing polymers was investigated to eliminate thermal cycling. Poly(ethylene terephthalate) was used as a model system for demonstration. Due to its slow crystallization, amorphous PET film can be made by casting a PET melt onto a chill roll. The amorphous PET film was embossed at a constant temperature of 180°C for a period of time comparable to or longer than PET’s half-time of crystallization. During constant-temperature embossing, the film first liquefies, caused by rubber softening of the amorphous phase, and then solidifies, resulting from the crystallization of the amorphous phase. Since the embossed film is hardened under the constant mold temperature, no cooling is needed. Selected micro features, including circular microchannels and high aspect ratio rectangular microchannels, were successfully embossed using a total cycle time about 40 s.

Crystallization of poly(ethylene terephthalate) filaments by infusion of ethanol upon cold drawing

Polymer ◽  
2015 ◽  
Vol 59 ◽  
pp. 26-34 ◽  
Author(s):  
Rina Khanum ◽  
Wataru Takarada ◽  
Arun Aneja ◽  
Takeshi Kikutani
Keyword(s):  
Ethylene Terephthalate ◽  
Cold Drawing ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene

scholarly journals New UV Curable Acrylated Urethane-Oligoesters Derived From Poly(Ethylene Terephthalate) PET Waste

2021 ◽  
Author(s):  
Medhat S. Farahat Khedr
Keyword(s):  
Ethylene Terephthalate ◽  
Value Added ◽  
Hydroxyl Groups ◽  
Polymer Waste ◽  
Uv Curable ◽  
Pet Waste ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene ◽  
High Mechanical Stress ◽  
Value Added Products

Abstract The glycolysis products of polyethylene terephthalate (PET) waste represent a potential source for many value-added products that contain terephthalate repeating units in their backbones. Terephthalate repeating units were not attained directly from terephthalic acid due to its high melting point in addition to its tendency to sublime before it reacts. Glycolysis of PET provides an excellent solution for recycling polymer waste and constitutes a substantial starting material for manufacturing materials with high mechanical stress, such as unsaturated polyesters and polyurethane products. In this study, PET was first depolymerized by glycolysis, and glycolyzed products were then dimerized by reaction with toluene di-isocyanate TDI with half equivalence of their hydroxyl groups for the purpose of inserting urethane blocks into the oligomer structure. The remaining half equivalence of terminal hydroxyl groups was modified into acrylate groups by an acrylation reaction. The acrylated oligo urethane ester products were crosslinked with different co-monomers and tested for UV curability and mechanical properties, and they showed outstanding results.

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