Effect of copolymers synthesized by nitroxide‐mediated polymerization as chain extenders of postconsumer poly(ethylene terephthalate) waste

2019 ◽  
Vol 59 (11) ◽  
pp. 2255-2264 ◽  
Author(s):  
Juan José Benvenuta‐Tapia ◽  
Eduardo Vivaldo‐Lima ◽  
Ramiro Guerrero‐Santos
Keyword(s):  
Ethylene Terephthalate ◽  
Poly Ethylene Terephthalate ◽  
Chain Extenders ◽  
Poly Ethylene ◽  
Nitroxide Mediated Polymerization

Calix[4]arenes Used as a New Type of Chain Extender in the Preparation of Polyurethanes

2007 ◽  
Vol 60 (3) ◽  
pp. 167 ◽  
Author(s):  
Qin Zheng ◽  
Shuling Gong ◽  
Haiqing Dong ◽  
Yuanyin Chen
Keyword(s):  
Ethylene Terephthalate ◽  
Toluene Diisocyanate ◽  
Elongation At Break ◽  
Poly Ethylene Terephthalate ◽  
Solvent Type ◽  
Lower Yield Strength ◽  
New Type ◽  
Chain Extenders ◽  
Poly Ethylene ◽  
Hydroxy Groups

A series of polyether– or polyester–polyurethanes based on tetrahydrofuran–propylene oxide copolyether diol (PTMG/PPG) or poly(ethylene terephthalate) diol (PET), toluene diisocyanate (TDI), and three kinds of chain extenders including two calix[4]arene derivatives and 3,3´-dichloro-4,4´-diaminodiphenylmethane (MOCA) were synthesized in toluene. The thermal stability and mechanical properties of solvent-type polyurethanes were investigated. Incorporation of calixarenes into polyurethane backbones improved the thermal properties of the polyurethane as a result of the residual phenol hydroxy groups of the calix[4]arene units. Compared with polyurethane chain-extended by MOCA, the polyurethanes with calix[4]arene derivatives had higher elongation at break, lower elastic modulus, and lower yield strength, as a result of the larger steric cubage of calix[4]arene units and relatively large free volume of the polymer.

Improving the properties of recycled PET/PEN blends by using different chain extenders

2016 ◽  
Vol 36 (6) ◽  
pp. 615-624 ◽  
Author(s):  
Simge Can ◽  
N. Gamze Karsli ◽  
Sertan Yesil ◽  
Ayse Aytac
Keyword(s):  
Ethylene Terephthalate ◽  
Chain Extender ◽  
Degree Of Crystallinity ◽  
Recycled Pet ◽  
H Nmr ◽  
Loading Level ◽  
Poly Ethylene Terephthalate ◽  
Chain Extenders ◽  
Izod Impact ◽  
Poly Ethylene

Abstract The main aim of this study was to improve the mechanical properties of the recycled poly(ethylene terephthalate)/poly(ethylene 2,6-naphthalate) (r-PET/PEN) blends by enhancing the miscibility between PET and PEN with the usage of chain extenders. This idea was novel for the recycled PET-based r-PET/PEN blends, as investigation of the effects of the chain extender usage on the properties of r-PET/PEN blends has not been studied in the literature, according to our knowledge. 1,4-Phenylene-bis-oxazoline (PBO), 1,4-phenylene-di-isocyanate (PDI), and triphenyl phosphite (TPP) were selected as chain extenders. The maximum tensile strength value was observed for the 1.0PDI sample. Moreover, PDI-based blends exhibited better Izod impact strength when compared with all other samples. The miscibility and degree of crystallinity values of all blends were discussed by means of thermal analysis. 1H-nuclear magnetic resonance (1H-NMR) analysis was carried out to determine transesterification reaction levels. According to 1H-NMR results, the increase in the level of transesterification was around 40% with the usage of PDI. The optimum loading level for selected chain extenders was determined as 1 wt.%, and PDI-based blends exhibited better properties when compared with those of the blends based on PBO and TPP at this loading level.

Microcellular injection molding of recycled poly(ethylene terephthalate) blends with chain extenders and nanoclay

2014 ◽  
Vol 34 (1) ◽  
pp. 5-13 ◽  
Author(s):  
Yottha Srithep ◽  
Lih-Sheng Turng
Keyword(s):  
Mechanical Properties ◽  
Injection Molding ◽  
Ethylene Terephthalate ◽  
Average Cell Size ◽  
Recycled Pet ◽  
Average Cell ◽  
Poly Ethylene Terephthalate ◽  
Microcellular Injection Molding ◽  
Chain Extenders ◽  
Poly Ethylene

Abstract Poly(ethylene terephthalate) (PET) resin is one of the most widely used thermoplastics, especially in packaging. Due to thermal and hydrolytic degradations, recycled PET (RPET) exhibits poor mechanical properties and lacks moldability. The effects of adding chain extender (CE) and nanoclay to RPET were investigated. Melt blending of RPET with CE was performed in a thermokinetic mixer (K-mixer). The blended materials were then prepared via solid and microcellular injection molding processes. The effects of CE loading levels and the simultaneous addition of nanoclay on the thermal and mechanical properties and cell morphology of the microcellular components were noted. The addition of 1.3% CE enhanced the tensile properties and viscosity of RPET. The higher amount of CE (at 3%) enhanced the viscosity, but the margin of improvement in mechanical properties diminished. While the solid RPET and CE blends were fairly ductile, the samples with nanoclay and all microcellular specimens showed brittle fractural behavior. Finally, nanoclay and the increase of CE content decreased the average cell size and enlarged the cell density of the microcellular samples.

Molecular structure and rheological properties of a poly(ethylene terephthalate) modified by two different chain extenders

2020 ◽  
Vol 138 (13) ◽  
pp. 50110
Author(s):  
Michael Härth ◽  
Andrea Dörnhöfer ◽  
Joachim Kaschta ◽  
Helmut Münstedt ◽  
Dirk W. Schubert
Keyword(s):  
Molecular Structure ◽  
Rheological Properties ◽  
Ethylene Terephthalate ◽  
Poly Ethylene Terephthalate ◽  
Chain Extenders ◽  
Poly Ethylene
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