Highly efficient fire retardant behavior, thermal stability, and physicomechanical properties of rigid polyurethane foam based on recycled poly(ethylene terephthalate)

Purpose Poly(ethylene terephthalate) (PET) waste from soft drink bottles was incorporated into palm olein alkyd to produce new polyol for use in polyurethane resins as surface protection on metal surfaces. Design/methodology/approach Alkyd was prepared from palm olein, glycerol and phthalic anhydride. PET underwent simultaneous glycolysis and transesterification reactions with the alkyd. Varying the amount of PET has led to polyols with different viscosities. Polyurethane resins were produced by reacting the polyols with toluene diisocyanate. The resins were coated on mild steel panels and cured. Performances of the cured films were tested. Findings The polyurethanes (PU) resin cured to a harder film with better thermal stability. Films showed excellent adhesion properties, while higher content of PET exhibited higher pencil hardness, better water, salt, acid and alkali resistance. Research limitations/implications Other vegetable oils could also be used. The alkyd structure could be changed by formulation to have different functionality and the ability to incorporate higher amount of PET waste. Rate of glycolysis of PET could be increased by higher amount of ethylene glycol. Practical implications This method has managed to use waste PET in producing new polyol and PU resins. The cured films exhibit good mechanical and chemical properties, as well as excellent adhesion and thermal stability. Social implications The non-biodegradable PET has created environmental pollution problems connected to littering and illegal landfilling. It has become necessary to pay greater attention to recycling PET bottles for obtaining valuable products. Originality/value This approach is different from the earlier reports, where PET was recycled to recover the raw materials.

Download Full-text

Novel Oligo-Ester-Ether-Diol Prepared by Waste Poly(ethylene terephthalate) Glycolysis and Its Use in Preparing Thermally Stable and Flame Retardant Polyurethane Foam

Polymers ◽

10.3390/polym11020236 ◽

2019 ◽

Vol 11 (2) ◽

pp. 236 ◽

Cited By ~ 10

Author(s):

Cuong N. Hoang ◽

Chi T. Pham ◽

Thu M. Dang ◽

DongQuy Hoang ◽

Pyoung-Chan Lee ◽

...

Keyword(s):

Flame Retardant ◽

Polyurethane Foam ◽

Flame Retardancy ◽

Ethylene Terephthalate ◽

Recycled Pet ◽

Pet Bottles ◽

Poly Ethylene Terephthalate ◽

Ul 94 ◽

Poly Ethylene ◽

Fire Properties

Rigid polyurethane foam (PUF) was successfully prepared from a novel oligo-ester-ether-diol obtained from the glycolysis of waste poly(ethylene terephthalate) (PET) bottles via reaction with diethylene glycol (DEG) in the presence of ZnSO4 7H2O. The LC-MS analysis of the oligodiol enabled us to identify 67 chemical homologous structures that were composed of zero to four terephthalate (T) ester units and two to twelve monoethylene glycol (M) ether units. The flame retardant, morphological, compression, and thermal properties of rigid PUFs with and without triphenyl phosphate (TPP) were determined. The Tg values showed that TPP played a role of not only being a flame retardant, but also a plasticizer. PUF with a rather low TPP loading had an excellent flame retardancy and high thermal stability. A loading of 10 wt % TPP not only achieved a UL-94 V-0 rating, but also obtained an LOI value of 21%. Meanwhile, the PUF without a flame retardant did not achieve a UL-94 HB rating; the sample completely burned to the holder clamp and yielded a low LOI value (17%). The fire properties measured with the cone calorimeter were also discussed, and the results further proved that the ﬂame retardancy of the PUF with the addition of TPP was improved significantly. The polymeric material meets the demands of density and compression strength for commercial PUF, as well as the needs of environmental development. The current study may help overcome the drawback of intrinsic high ﬂammability and enlarge the ﬁre safety applications of materials with a high percentage of recycled PET.

Download Full-text

Effect of chemical surface treatment on thermal stability of poly(ethylene terephthalate) films used in flexible circuits

Polymer Degradation and Stability ◽

10.1016/j.polymdegradstab.2004.11.018 ◽

2005 ◽

Vol 88 (3) ◽

pp. 461-467 ◽

Cited By ~ 7

Author(s):

S.C. Domenech ◽

V.L.S. Severgnini ◽

E.A. Pinheiro ◽

A.O.V. Avila ◽

N.G. Borges ◽

...

Keyword(s):

Thermal Stability ◽

Surface Treatment ◽

Ethylene Terephthalate ◽

Chemical Surface ◽

Poly Ethylene Terephthalate ◽

Poly Ethylene ◽

Thermal Stability Of

Download Full-text

Assessment of the PETase Conformational Changes Induced by Poly(ethylene terephthalate) Binding

10.22541/au.161530497.73055461/v1 ◽

2021 ◽

Author(s):

Clauber Henrique Costa ◽

Alberto dos Santos ◽

Cláudio Nahum Alves ◽

Sérgio Martí ◽

Vicente Moliner ◽

...

Keyword(s):

Thermal Stability ◽

Conformational Changes ◽

Active Site ◽

Terephthalic Acid ◽

Structural Changes ◽

Ethylene Terephthalate ◽

Md Simulations ◽

Poly Ethylene Terephthalate ◽

Bounded State ◽

Poly Ethylene

Recently, a bacterium strain of Ideonella sakaiensis was identified with the uncommon ability to degrade the poly(ethylene terephthalate) (PET). The PETase from I. sakaiensis strain 201-F6 catalyzes the hydrolysis of PET converting it to mono(2-hydroxyethyl) terephthalic acid (MHET), bis(2-hydroxyethyl)-TPA (BHET), and terephthalic acid (TPA). Despite the potential of this enzyme for mitigation or elimination of environmental contaminants, one of the limitations of the use of PETase for PET degradation is the fact that it acts only at moderate temperature due to its low thermal stability. Besides, molecular details of the main interaction of PET in the active site of PETase remains unclear. Herein, molecular docking and molecular dynamics (MD) simulations were applied to analyze structural changes of PETase induced by PET binding. Results from the essential dynamics revealed that β1-β2 connecting loop is very flexible. This Loop is located far from the active site of PETase and we suggest that it can be considered for mutagenesis in order to increase the thermal stability of PETase. The free energy landscape (FEL) demonstrates that the main change in the transition between the unbounded to the bounded state is associated with β7-α5 connecting loop, where the catalytic residue Asp206 is located. Overall, the present study provides insights into the molecular binding mechanism of PET into the PETase structure and a computational strategy for mapping flexible regions of this enzyme, which can be useful for the engineering of more efficient enzymes for recycling the plastic polymers using biological systems.

Download Full-text

Effects of Halloysite Nanotubes on Mechanical and Thermal Stability of Poly(Ethylene Terephthalate)/Polycarbonate Nanocomposites

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.735.8 ◽

2015 ◽

Vol 735 ◽

pp. 8-12

Author(s):

Nurul Ain Jamaludin ◽

Azman Hassan ◽

Norhayani Othman ◽

Mohammad Jawaid

Keyword(s):

Thermal Stability ◽

Ethylene Terephthalate ◽

Flexural Modulus ◽

Halloysite Nanotubes ◽

Mechanical And Thermal Properties ◽

Poly Ethylene Terephthalate ◽

Twin Screw ◽

Poly Ethylene ◽

The Impact ◽

Thermal Stability Of

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.

Download Full-text