Journal ArticleDOI
Modification of Crystallinity and Structure in Powder Processing of Polytetra Fluoroethylene
S. Radhakrishnan,V. M. Nadkarni +1 more
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TLDR
In this paper, the modification of structure, crystallinity and orientation have been studied in powder processed polytetrafluoroethylene by various techniques and it was found that the crystallinity in unsintered samples decreased with increase of compaction pressure while in sintered specimens it increased with an increase of pressure.Abstract:
The modification of structure, crystallinity and orientation have been studied in powder processed polytetrafluoroethylene by various techniques. It was found that crystallinity (as determined from regression curve analysis) in unsintered samples decreased with increase of compaction pressure while in sintered specimen it increased with increase of pressure. The crystallinity was also found to vary inversely with logarithm of cooling rate. Microfocus X-ray diffraction revealed the orientation of c-axis lying preferentially in the plane perpendicular to applied pressure. There was slight variation in the lattice dimension especially the c-axis in completely sintered specimen. The infrared studies showed the presence of some of the bands depended upon the molding/sintering conditions. These various findings have been explained on the basis of compaction and recrystallization behaviour under constrained conditions.read more
Citations
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High-temperature, polymer-graphite hybrid composites for bipolar plates: Effect of processing conditions on electrical properties
TL;DR: In this article, the effect of a third conducting component on the electrical resistance of high-temperature thermoplastic-graphite composites is studied, and the results show that a low resistance of the order of 0.1 Ω can be obtained even for a graphite concentration of 50% by addition of the third component.
Journal ArticleDOI
Effect of CaCO3 on the crystallization behaviour of polypropylene
TL;DR: In this paper, the effect of CaCO3 on polypropylene (PP) crystallization behavior and the modification of structure was investigated using X-ray diffraction and optical microscopy.
Journal ArticleDOI
Thermoplastic Vinyl Polymers: From Macro to Nanostructure
TL;DR: In this article, a structural overview of synthetic thermoplastic polymers and their physicochemical characteristics, structure-property relationships, applications, and limitations are discussed. But, the authors do not provide a thorough overview of the synthetic vinyl polymer classes available.
Journal ArticleDOI
Structure development in polyvinylidene fluoride containing oxide fillers and additives
S. Radhakrishnan,Roy Joseph +1 more
TL;DR: In this paper, the effect of additives, inorganic oxides such as PbO, TiO2, CoO and pigments such as copper-phthalocyanine on crystalline phase and morphology of polyvinylidene fluoride has been investigated.
Journal ArticleDOI
Fabrication of Polypropylene Super-Hydrophobic Surface Using PTFE-Coated-Sieves Template via Templating and Splitting Process
TL;DR: In this article, a super-hydrophobic polypropylene surface was prepared employing combination method of replicating an artificial template and subsequent lifting off the master via a splitting way, which was prepared using a 500mesh PTFE-coated sieve, has gradient structures that microbumps with typical height and radius of approximately 20 µm and nano bundles on top of the bump surface.
References
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Book
Encyclopedia of polymer science and technology
TL;DR: In this article, the authors present a survey of the properties of polymers and their application in the field of chemical engineering, including the following: Coextrusion, Injection Molding, Flexible Packaging, Fibers, Polymer-Clay, and Plasticizers.
Journal ArticleDOI
Structures of Molecules and Crystals of Fluoro-Carbons
C. W. Bunn,E. R. Howells +1 more
Book ChapterDOI
Infrared spectra of high polymers
TL;DR: In this article, the spectral properties of polyethylene terephthalate and three deuterated analogs have been obtained in the region of 70 to 3600 cm-i, polarized spectra having been obtained down to 330 cm-l. This assignment suggests a modification of the proposed chain structure of this polymer.
Journal ArticleDOI
X‐Ray Diffraction Methods
TL;DR: In this paper, the identification of crystalline materials, preferred orientations, particle sizes, strains, and structure randomness, x-ray diffraction is used to learn more about the identification.