Polyurethane Waste Reduction and Recycling: From Bench to Pilot Scales

Nikje, Mir Mohammad Alavi; Garmarudi, Amir Bagheri; Idris, Azni

doi:10.1163/138577211x587618

Cited by 75 publications

(51 citation statements)

References 67 publications

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“…PU foam waste can be recycled using physical, thermochemical, and chemical methods. The physical recycling methods include regrinding, rebinding, adhesive pressing, injection molding, and compress molding, while the most common chemical methods are hydrolysis, aminolysis, and glycolysis [7]. Glycolysis processes have been reported for a great variety of polyurethane products, including elastomers, coatings, rigid foams, flexible foams, reaction injection molding, reinforced reaction injection molding polyurethanes [5], and even high resilience flexible PU foams [8].…”

Section: Introductionmentioning

confidence: 99%

Recovery of Flexible Polyurethane Foam Waste for Efficient Reuse in Industrial Formulations

et al. 2020

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Ester polyurethane (PU) foam waste was reacted at atmospheric pressure in an autoclave and using microwaves with diethylene glycol (DEG) at different PU/DEG ratios in the presence of diethanolamine as a catalyst to find the glycolysis conditions that allow for the improved recovery of the PU foam waste and enable the recycling of the whole glycolysis product in foam formulations suitable for industrial application. The recycled polyol was characterized by dynamic viscosity, hydroxyl number, water content, and density, while thermal stability was assessed using thermogravimetric analysis. In the PU foam formulation, 1% and 5% of the glycolyzed material was reused. The relationship between the reuse level of the recycled polyol and the physical properties of the foam was thoroughly investigated. It was observed that both hardness and air flow decreased with increasing recycled polyol content, particularly for the polyester type foam, while tensile strength and compression strength increased. Depending on the amount of recycled polyol and catalyst used, polyether-based foams could be obtained with a low air permeability, needed in special applications as sealed foams, or with higher air permeability desirable for comfort PU foams. The results open the way for further optimization studies of industrial polyurethane foam formulations using a glycolysis process without any separation stage.

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Section: Introductionmentioning

confidence: 99%

Recovery of Flexible Polyurethane Foam Waste for Efficient Reuse in Industrial Formulations

et al. 2020

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“…Nowadays, chemical or thermochemical processes do not seem to be the most effective solution for PU recycling: mechanical processes should be preferred. Mechanical regrinding is the oldest method in PU waste recycling and the use of regrind wastes as filler in new formulations [10]. PU recycled granules can be mixed with virgin materials and reused in typical production processes such as injection molding or compression molding.…”

Section: Introductionmentioning

confidence: 99%

Recycling of thermoset polyurethane foams

Quadrini

Bellisario

Santo

2012

Polymer Engineering & Sci

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A new way for recycling polyurethane (PU) foams is shown by scrap pulverization and subsequent compression molding of resulting particles. The compression molding stage is also called “direct molding” to highlight the absence of any linking agent or virgin material. Large disks, 190 mm in diameter, were molded by recycling foam scraps from motorcycle seats. Aluminum alloy molds and a hot parallel press plate press were used: the molding temperature was fixed to 180°C, the molding pressure to 4.2 MPa, and the molding time to 15 min, whereas the weight of the particles to mold was changed so as to obtain disks with different thickness. The final density of molded product was close to 1 g/cm3, resulting in a compacting factor of 14 in comparison with the initial PU foam. Indentation tests and tensile tests showed that final products exhibit good mechanical performances

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“…The absence of an NCO peak at 2285–2250 cm −1 implies that the reaction has gone to completion. All these spectral changes provide convincing evidence for the formation of fluorescently labeled polyurethane . Figure shows the 1 H‐NMR spectra of PLGU30, PLGU30‐N01, PLGU30‐E01, and PLGU30‐D01.…”

Section: Resultsmentioning

confidence: 99%

Fluorescently labeled degradable thermoplastic polyurethane elastomers: Visual evaluation for the degradation behavior

Liu

Shi

et al. 2015

J of Applied Polymer Sci

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Thermoplastic polyurethane elastomers (TPU) were synthesized with isophorone diisocyanate (IPDI) as the rigid segment, poly(lactic-co-glycolic acid) (PLGA-PEG-PLGA) diol as soft segment, and 1,4-butanediol (BDO) as the chain extender. During the chain extension process, three kinds of fluorescent monomers 4-(2-hydroxyethylamino)21,8-naphthoyl-(2-hydroxyethyl)imide (HNHI), 1,5-dihydroxy naphthalene (DHN), and dicoumarin (DIC) were introduced to get the fluorescently labeled degradable TPUs. The structure and degradation properties of the TPUs were characterized in detail. The results showed that there was no significant effect found on average molecular weight, mechanical properties, and glass transition temperature of polyurethane by introducing 0.001% (wt) weight percent of fluorescence monomers. The degradation behavior of fluorescent-tagged thermoplastic elastomer has been characterized with fluorescence microscopy. Results showed that polyurethane elastomers, in which fluorescence monomers especially HNHI were introduced by chemical reaction, had more homogeneous and stable fluorescence intensity than that with fluorescence monomers introduced by post blending. This work also provides a promising visual characterization approach to monitor degradation behavior of degradable TPUs for tissue engineering applications or drug delivery system.

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Polyurethane Waste Reduction and Recycling: From Bench to Pilot Scales

Cited by 75 publications

References 67 publications

Recovery of Flexible Polyurethane Foam Waste for Efficient Reuse in Industrial Formulations

Recovery of Flexible Polyurethane Foam Waste for Efficient Reuse in Industrial Formulations

Recycling of thermoset polyurethane foams

Fluorescently labeled degradable thermoplastic polyurethane elastomers: Visual evaluation for the degradation behavior

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