Polyethylene terephthalate infrared spectroscopy

Boston, Ma., March 1999, p.627-8. 012 ELUCIDATION OF CRYSTALLINE STRUCTURE IN POLYETHYLENE TEREPHTHALATE BY EXTERNAL REFLECTION INFRARED SPECTROSCOPY Cole K C Ajji A Pellerin E Canada,National Research Council (ACS,Div.of Polymer Chemistry)... 

A better understanding of NNSM-induced morphological changes has been initiated by employing synchrotron-based infrared micro-spectroscopy. In this recent study [17], authors have chosen three common semi-crystalline and amorphous polymers for blending Hydrophobic polymers polystyrene (PS), polyethylene terephthalate (PET), and poly(methyl-methacrylate) (PMMA) labelled hereafter PS/PET and PET/PMMA. The results of such studies clearly show the potential of the synchrotron technique to detect the transition region between the two polymers, and provide evidence for the fluctuations in blend concentration for PS/PMMA. 

In the Master s dissertation entitled Effect of natural and accelerated ageing on the properties of PET/PC (80/20) blend , recycled polyethylene terephthalate (rPET) was blended with PC (80/20 wt/wt), and then submitted to natural ageing in the city of Rio de Janeiro [17]. For comparison purposes, we also monitored the accelerated ageing of the blend in an appropriate chamber under the same conditions, 2,000 h of exposure were performed. The Fourier-Transform infrared spectroscopy revealed the tendency of the PET and PC carbonyl indices to decrease upon an increase in... 

Miller CE, Eichinger BE. Determination of crystalhnity and morphology of fibrous and bulk polyethylene terephthalate by near-infrared diffuse reflectance spectroscopy. Appl Spectrosc 1990 44 496-504. 

C. Y. Liang and S. Krimm, Infrared Spectra of High Polymers. Part IX. Polyethylene Terephthalate, J. Mol. Spectroscopy 3, 554, 1959. 

UHMWPE were specifically identified (e.g., polyethylene terephthalate [PET], polyethylene [PE], polyamide, polyvinyl alcohol [PVOH]) by declaration of the manufacturer and by using Fourier transform infrared spectroscopy (FTIR) (System 2000, Perkin-EImer, Shelton, Connecticut, USA). The packaging materials were identified as one of seven types, as summarized in Table 3.3. 

Virgin and recycled polyethylene terephthalate (PET) was blended with polyether-imide (PEI) in proportions between 0 and 50 percent PEI content and samples were examined by differential scaiming calorimetry and Fourier transform infrared spectroscopy. All blends were completely miscible, as indicated by a single glass transition temperature which is dependent on blend composition. Crystallisation rates of PET were retarded strongly at 20 percent PEI content and above, but degree of crystallinity was easily determined from a linear correlation between a structural parameter measured spectroscopically and enthalpy of fusion. Trans conformer activation energy measurement confirmed the effects of PEI content on crystallisation of PET. 9 refs. 

Identification of plastics can be as simple as finding the resin identification code (typically on the bottom of the component) or as complex as separating the base resin from the filler, reinforcements, and colorants to analyze via infrared (IR) spectroscopy. The resin identification codes developed by the Society of Plastics Industry in 1998 are shown in Table 1.5. Despite the desire of many individuals to recycle, many communities recycle often only recycle plastics polyester (polyethylene terephthalate (PET)) and high-density polyethylene (HDPE). In fact, local recycling companies in the United States will often bury plastics in a landfill, either with the rest of the waste or in separate locations, ostensibly to mine at a later date. Collected recyclables are also shipped from the United States as baled... 

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