Polyethylene terephthalate morphology

In semi-cristalline polymers, rate-enhancement under stress has been frequently observed, e.g. in UV-photooxidation of Kapron, natural silk [80], polycaprolactam and polyethylene terephthalate [81]. Quantitative interpretation is, however, difficult in these systems although the overall rate is determined by the level of applied stress, other stress-dependent factors like the rate of oxygen diffusion or change in polymer morphology could occur concurrently and supersede the elementary molecular steps [82, 83], Similar experiments in the fluid state showed unequivocally that flow-induced stresses can accelerate several types of reactions, the best studied being the hydrolysis of DNA [84] and of polyacrylamide [85]. In these examples, hydrolysis involves breaking of the ester O —PO and the amide N —CO bonds. The tensile stress stretches the chain, and therefore, facilitates the... 

Sometimes, small structural differences in morphology of polymer samples can be isolated by using a double subtraction technique. For example, with polyethylene terephthalate) PET, differences in the amorphous phase of the melt-quenched polymer and solution-cast polymer can be isolated by first subtracting out the contribution due to the trans isomer and then subtracting the two difference spectra from each other 214). (Fig. 16) shows the resultingdifference spectrum obtained after the second subtraction. Obviously the two amorphous structures are different from each other. 

Sanchez-Solis, A. Estrada, M.R. Cruz, J. Manero, O. On the properties and processing of polyethylene terephthalate/styrene-butadiene rubber blend. Polym. Eng. Sci. 2000,40 (5), 1216-1225. Luzinov, I. Xi, K. Pagnoulle, C. Huynh-Ba, G. Jerome, R. Composition effect on the core-shell morphology and mechanical properties of ternary polystyrene/styrene butadiene rubber polyethylene blends. Polymer 1999, 40 (10), 2511-2520. 

Morphology of bottle (high-density polyethylene [HOPE]/polyethylene terephthalate (PET) blend) taken through an optical microscope at magnification of 200x. 

The use of a fibre-coupled confocal Raman microscope and an infrared microscope for both point mapping and global imaging in the study of spatial variations in polymer chemistry and morphology is illustrated by studies of the curing of the UV-cured acrylate coatings, crystallinity in drawn polyethylene terephthalate (PET) film, molecular orientation in PET bottles, and the analysis of a PES/PEES copolymer blended with epoxy resin and cured at elevated temperature. 8 refs. 

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. 

To prepare membranes with artificial nanochannels, one can start with several polymer materials such as polyimide (PI), polycarbonate (PC), and polyethylene terephthalate (PET). A prerequisite to apply these kinds of polymers for nanochannel fabrication is that they are easy to process and susceptible to different etching techniques to produce nano-sized channels of different morphologies. Current methods for this purpose include ion-track-etching, electrochemical etching, and laser techniques. Once the nanochannels have been produced, one needs to functionalize the channel inner wall to obtain different functions. Following are some examples of polymer decorated nanochannels. 

In this chapter, the crystallization of these two engineering polymers, namely, polyethylene terephthalate (PET) and polyphenylene suffide (PPS), will be discussed with reference to the various aspects of crystallization. The effects of various parameters on the crystallization process and crystalline morphology of these polymers will also be discussed. 

L.G. Carreira in Composites of Polyethylene Terephthalate and Modified Graphite with Octadecylamine Structural, Thermal Mechanical and Morphological Characteristics, Institute de Macromoleculas Professora Eloisa Mano, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil, 2012. [Doctoral Thesis]... 

Chen C., Wang L. and Huang Y. (2008), Morphology and thermal properties of electrospun fatty acids/polyethylene terephthalate composite fibers as novel form-stable phase change materials. Solar Energy Materials Solar Cells, 92 pp. 1382-1387. 

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. 

The application of AFM to surface morphological studies has been covered in relation to the following polymers polyesters, polyethylene (PE), polystyrene (PS) [28], polycarbonate, polyimide, polytetrafuoroethylene (PTFE) [29], polyurethane (PU) [30], rubbers [31], polyethylene glycol (PEG) [32], PS and poly(N-butyl-methacrylate) [33], PS [34], PP [35, 36], polyethers [37], polyorthoesters [38], poly(p-phenylene-vinylene) [39], bisphenol A-1, 8-dibromooctane copolymer [40], polycatechol [41], polyethylene terephthalate (PET) [42], poly(p-dioxanone)-poly(epsilon caprolactone) [43], poly(L-lactide-polyethylene glycol) [44] and polyvinylidene fluoride [45]. 

Loyens W, Groeninckx G. Phase morphology development in reactively compatibiUzed polyethylene terephthalate elastomer blends. Polymer 2002 44 4929-4941. 

Sukhadia AM, Done D, Baird DG (1990) Characterizatimi and processing of blends of polyethylene terephthalate with several liquid crystalline polymers. Polym Eng Sci 30(9) 519-526 Thranas LD, Roth DD (1990) Films from liquid-oystals. Chemtech 20(9) 546-550 Tjong SC (2003) Stracture, morphology, mechanical and thermal characteristics of the in situ composites based on liquid crystalline polymers and thermoplastics. Mater Sci Eng R Rep 41 (l) l-60... 

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