|Series||Polymer symposia -- No.18|
|Contributions||Price, Fraser P.|
|The Physical Object|
|Number of Pages||148|
A polymer (/ ˈ p ɒ l ɪ m ər /; Greek poly-, "many" + -mer, "part") is a large molecule, or macromolecule, composed of many repeated subunits. Due to their broad range of properties, both synthetic and natural polymers play essential and ubiquitous roles in everyday life. Polymers range from familiar synthetic plastics such as polystyrene to natural biopolymers such as DNA and proteins that. The Meaning of crystallinity in polymers; American Chemical Society symposium held at Phoenix, Arizona, Janu Author: Fraser P Price ; American Chemical Society. A. Riley, in Packaging Technology, Crystallinity. Crystallinity, as applied to polymers, can be defined as the fraction of a polymer that consists of regions showing three-dimensional polymers have some degree of crystallinity. Those with little crystallinity are known as amorphous polymers, for example low density polyethylene or amorphous polyethylene terephthalate. Crystallization of polymers is a process associated with partial alignment of their molecular chains. These chains fold together and form ordered regions called lamellae, which compose larger spheroidal structures named spherulites. Polymers can crystallize upon cooling from melting, mechanical stretching or solvent evaporation. Crystallization affects optical, mechanical, thermal and chemical.
The closest to "theory" is the determination of the density of % crystalline polymer (if possible!) using the single crystal X-ray diffraction method and the unit cell size. % crystallinity. Introduction to Materials Science, Chap Polymer Structures University Tennessee, Dept. of Materials Science and Engineering 1 Chapter Outline: Polymer Structures Polymer Crystallinity (III) Crystalline polymers are denser than amorphous polymers, so the . POLYMERS • A polymer is a macromolecule (long molecules) built of small covalently bonded units called monomers (“mer” from the Greek word meros meaning part). • These small units are repeated throughout the macromolecule chain. • The macromolecules are bonded together by weak Van der Waals. Advanced Lab: DSC Investigation of Polymers 1 Introduction Di erential scanning calorimetry (DSC) is a technique used to investigate the response of polymers to heating. DSC can be used to study the melting of a crystalline polymer or the glass transition. The DSC set-up is composed of a measurement chamber and a computer. Two pansFile Size: 1MB.
The crystallinity of the polymers used in this study decreases in the order PE > PP > PET > PS > PVC (Demirell et al., ; Li et al., ). This characteristic could explain the high adsorption. Polymer molecules - mers, chemistry, common polymers 1a. Some Basic Terminology. Because polymers are so much larger than other molecules, they are often known as macromolecules. A mer is a repeating unit that makes up a polymer. The term comes from the Greek word "Meros" meaning part. From this, the term polymer was created to mean many mers. Characteristics of Polymers. The majority of manufactured polymers are thermoplastic, meaning that once the polymer is formed it can be heated and reformed over and over again. This property allows for easy processing and facilitates recycling. The other group, the thermosets, cannot be remelted. Answer to Explain the meaning of these terms: creep, stress relaxation, crazing, blushing, environmental stress cracking, and.