Rheological and Thermal Behavior of Recycled PET Modified by PMDA

2011 ◽  
Vol 391-392 ◽  
pp. 688-691 ◽  
Author(s):  
Ming Yi Wang ◽  
Zhi Qiang Guo ◽  
Bu Yu Lei ◽  
Nan Qiao Zhou

In this work pyromellitic dianhydride (PMDA) was used as the chain extender to increase the molecular weight of the recycled poly(ethylene terephthalate) (R-PET) and improve the rheological properties of the R-PET. The reaction was performed in a Brabender torque rheometer. The rheological and thermal characterization were performed by means of a fusion index instrument and a differential scanning calorimeter (DSC ) to compare the effectiveness of the chain extending reaction of different percentages of PMDA. The experimental results showed that compared with the unmodified R-PET, the addition of PMDA decreased the melt flow index and increased the viscosity of the R-PET. In addition, increased crystallization temperatures ( ) were observed with the modified R-PET. It was also found that the modified R-PET with the concentration of 1.0wt% PMDA exhibited the lowest MFI.

2016 ◽  
Vol 36 (6) ◽  
pp. 615-624 ◽  
Author(s):  
Simge Can ◽  
N. Gamze Karsli ◽  
Sertan Yesil ◽  
Ayse Aytac

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.


1997 ◽  
Vol 67 (9) ◽  
pp. 684-694 ◽  
Author(s):  
J. Radhakrishnan ◽  
Takeshi Kikutani ◽  
Norimasa Okui

Sheath-core bicomponent spinning of high molecular weight poly (ethylene terephthalate) (hmpet, IV = 1.02 dl/g) and low molecular weight pet (lmpet, IV = 0.65 dl/g) is done at a take-up velocity range of 1 to 7 km/min. The structures of the individual components in the as-spun bicomponent fibers are characterized. Orientation and orientation-induced crystallization of the hmpet component are enhanced, while those of the lmpet component are suppressed in comparison to corresponding single component spinning. Numerical simulation with the Newtonian model shows that elongational stress in the hmpet component is enhanced and that of the lmpet decreases during high-speed bicomponent spinning. The difference in elongational viscosity is the main factor influencing the mutual interaction between hmpet and lmpet, which in turn affect spinline dynamics, solidification temperature, and structural development in high-speed bicomponent spinning. Simulation with an upper-convected Maxwell model shows that considerable stress relaxation can occur in the lmpet component if the hmpet component solidifies before lmpet. A mechanism for structural development is also proposed, based on the simulation results and structural characterization data.


Polymer ◽  
1997 ◽  
Vol 38 (24) ◽  
pp. 6079-6081 ◽  
Author(s):  
Kwan Han Yoon ◽  
Sang Cheol Lee ◽  
Il Hyun Park ◽  
Hyang Mok Lee ◽  
O.Ok Park ◽  
...  

2018 ◽  
Vol 772 ◽  
pp. 33-37
Author(s):  
Nattakarn Hongsriphan ◽  
Pajaera Patanathabutr ◽  
Kanyakarn Lappokachai

Recycled poly (ethylene terephthalate) or R-PET is conventionally melt blended with polycarbonate with the presence of chain extender in order to produce polymer blend that provides good mechanical properties and cost effectiveness. This research was carried out to improve properties of such a blend by compounding them with silane treated hollow glass microspheres (HGMs), which mixing procedure was emphasized how it could affect mechanical properties. R-PET/PC/HGM composites of a fixed composition were melt compounded with three different mixing procedures. It was found that the compounding HGMs with PC and then R-PET obtained the most rigidity specimens than the all-in-one compounding or the compounding HGMs with R-PET and then PC. Silane treated HGMs were well distributed in the polymer matrix presenting good interfacial adhesion. However, the notched impact strength of all composites were inspected to be in the same range.


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