Polymer Chemistry An Introduction, Raymond B. Seymour and Charles E. Seymour/Carraher's Polymer Chemistry: Sixth Edition, Revised and Expanded. Introduction to Polymer Chemistry. Frank W. Harris. Wright State University, Dayton, OH Polymers are extremely large molecules that are essential. Lecture Notes: Introduction To Polymer Chemistry. Polymer: A large molecule (macromolecule) built up by repetitive bonding (covalent) of.
|Language:||English, Spanish, Japanese|
|Genre:||Health & Fitness|
|Distribution:||Free* [*Register to download]|
volume of the Practical Approach in Organic Chemistry series, and whilst initially I could see the value of . Synthesis of an acrylate-based liquid crystal polymer. Polymers are the giant molecules of chemistry. • Chemists also call them macro- molecules. • The small building-block molecules are called monomers. chemistry has done, where ~t has had the brggest effect on everyday life The world . few years by the application of' polymer physics and physical chemistry to.
Authors view affiliations A. Front Matter Pages i-xv. Introduction and Nomenclature. Pages Physical Properties and Physical Chemistry of Polymers.
Free-Radical Chain-Growth Polymerization.
Ionic Chain-Growth Polymerization. Ring-Opening Polymerizations. Common Chain-Growth Polymers. For example, the structure of a crystalline protein or polynucleotide, such as a sample prepared for x-ray crystallography , may be defined in terms of a conventional unit cell composed of one or more polymer molecules with cell dimensions of hundreds of angstroms or more.
Synthetic polymers may consist of both crystalline and amorphous regions; the degree of crystallinity may be expressed in terms of a weight fraction or volume fraction of crystalline material.
Few synthetic polymers are entirely crystalline. Polymers with microcrystalline regions are generally tougher can be bent more without breaking and more impact-resistant than totally amorphous polymers. For many polymers, reduced crystallinity may also be associated with increased transparency.
Chain conformation The space occupied by a polymer molecule is generally expressed in terms of radius of gyration , which is an average distance from the center of mass of the chain to the chain itself. Alternatively, it may be expressed in terms of pervaded volume , which is the volume of solution spanned by the polymer chain and scales with the cube of the radius of gyration.
The bulk properties of a polymer are those most often of end-use interest. These are the properties that dictate how the polymer actually behaves on a macroscopic scale.
Tensile strength The tensile strength of a material quantifies how much elongating stress the material will endure before failure. For example, a rubber band with a higher tensile strength will hold a greater weight before snapping.
In general, tensile strength increases with polymer chain length and crosslinking of polymer chains. Young's modulus of elasticity Young's modulus quantifies the elasticity of the polymer.
It is defined, for small strains , as the ratio of rate of change of stress to strain. Like tensile strength, this is highly relevant in polymer applications involving the physical properties of polymers, such as rubber bands.
The modulus is strongly dependent on temperature. Viscoelasticity describes a complex time-dependent elastic response, which will exhibit hysteresis in the stress-strain curve when the load is removed. Dynamic mechanical analysis or DMA measures this complex modulus by oscillating the load and measuring the resulting strain as a function of time. Transport properties Transport properties such as diffusivity describe how rapidly molecules move through the polymer matrix.
These are very important in many applications of polymers for films and membranes. The movement of individual macromolecules occurs by a process called reptation in which each chain molecule is constrained by entanglements with neighboring chains to move within a virtual tube.
The theory of reptation can explain polymer molecule dynamics and viscoelasticity. As the temperature increases, both amorphous and semicrystalline polymers go through the glass transition Tg.
Amorphous polymers A do not exhibit other phase transitions, though semicrystalline polymers B undergo crystallization and melting at temperatures Tc and Tm, respectively. Depending on their chemical structures, polymers may be either semi-crystalline or amorphous. Semi-crystalline polymers can undergo crystallization and melting transitions , whereas amorphous polymers do not. In polymers, crystallization and melting do not suggest solid-liquid phase transitions, as in the case of water or other molecular fluids.
Instead, crystallization and melting refer to the phase transitions between two solid states i.
Crystallization occurs above the glass transition temperature Tg and below the melting temperature Tm. Glass transition All polymers amorphous or semi-crystalline go through glass transitions. Author s: NA NA Pages.
Similar Books. Polyester Production, Characterization and Innovative Applications This book provides leading edge research on improvements of functional properties of polyester, modifications of unsaturated polyester resins, and polyester usage in construction and in automotive application areas in the form of fiber, resin, and composite.
Nurhan Onar Camlibel 98 Pages. Polymer Science and Engineering This note explains the following topics: Stanford University NA Pages. Introduction to polymer science Lecture Notes This note covers the following topics: Polymer Science This book explains the following topics: Faris Yilmaz Pages.