General properties and applications of thermoplastics. Polymers the basic materials of the rubber and plastic industries and important to the textile, petroleum, automobile, paper, and pharmaceutical industries as well exhibit viscoelasticity to a pronounced degree. Polymers range from familiar synthetic plastic such as polystyrene to natural biopolymers such as dna and proteins that are fundamental to biological structure and function. Polymers range from familiar synthetic plastics such as polystyrene to natural biopolymers such as dna and proteins that. The general polymers product line represents one of the broadest seamless flooring lines in the industry. Physical properties of polymers textile study center. We present a general theory for the intrinsic viscosity of flexible polymers of arbitrary architecture.
Epoxy resins are a family of monomelic or oligomeric material that can be further reacted to form thermoset polymers possessing a high degree of chemical and solvent resistance, outstanding adhesion to a broad range of substrates, a low order of shrinkage on cure, impact resistance, flexibility, and good electrical properties. Their use gives a significant touch to the valves making them flexible, durable and of optimum performance which totally suffices the needs of the market. These issues will be discussed at length in the next chapter. Mcq quiz on polymers multiple choice questions and answers on polymers mcq questions quiz on polymers objectives questions with answer test pdf. Polymers are materials with a seemingly limitless range of characteristics and colors. Polymers are materials consisting of very long molecules. Physical structure of polymers, small vs large molecules, molecular features, some physical technique for studying polymers, molecular sizes and shapes and ordered structures, polymer blends and copolymers, polymer blends and copolymers, regular chains and crystallinity, morphology and motion, morphology morphology and motion. Polymers can be made to mimic cotton, silk, and wool fibers. The following variables can be controlled when producing a polymer.
Chain forms when same basic unit is repeated over and over. The polymers used by us add a lot of years to the life of the valves produced. Since data tend to be widely scattered over many sources and are very scarce compared to the conventional polymers, it is the purpose of this article to give an overview of the most relevant properties of a range of biodegradable polymers. Due to their broad range of properties, both synthetic and natural polymers play essential and ubiquitous roles in everyday life. Polyethylene polymers can be broadly categorised into branched and linear polyethylenes, however, categorisation.
The weak coupling limit of disordered copolymer models caravenna, francesco and giacomin, giambattista, the annals of probability, 2010. Polymers multiple choice questions and answers mcq. Professionals, teachers, students and kids trivia quizzes to test your knowledge on the subject. Characteristics, applications and properties of polymers. General properties 1 introduction polyethylene is a versatile thermoplastic polymer consisting of long hydrocarbon chains. Many of the useful properties of polymers are in fact unique to polymers and are due to their long chain molecular structure. Reinforcement this is a discontinuous phase and is a principal loadbearing component. Neoprene is a polymer of chloroprene and is considered a general or allpurpose rubber. Matrix this is the polymer, which is a continuous phase and is classified as the weak link in a pmc structure. S ramaiah school of advanced studies bangalore 3 advantages of polymers. Several features of mechanical behaviour of polymers are discussed, including major effects of temperature and time scale of measurement. Structure of polymers different type of polymers properties of polymers applications of polymers.
In this chapter, focus will be on general characteristics, applications and an introduction to the mechanical behavior including elementary concepts of their. Thermosetting polymers become permanently hard at elevated temperatures and pressures. Physical, thermal, and mechanical properties of polymers. Mechanical properties of linear and crosslinked polymers filled with detailed graphs to help explain important quantitative trends, physical properties of macromolecules teaches by example, ensuring comprehension of the subject as well as the methodology to implement theory, problemsolving techniques, and research results in practical situations. Properties of plastics or polymers play a vital role in the field of mechanical engineering. When you want to apply any type of load on a particular member, you need to know its material properties, density, etc. Localization of directed polymers with general reference walk bates, erik, electronic journal of probability. Inorganic polymer chemistry pdf 30p this note covers the following topics. This lesson introduces students to polymers, their properties, and some of the many ways polymers. In fact, the basic molecular structure of all plant and animal life is similar to that of a synthetic polymer. A condition to obtain crosslinked polymers is that at least one of the monomers has a functionality higher than 2. General properties of plastics use of polymers notes. In this chapter, we describe general properties of hydrogels formed by freeradical crosslinking copolymerization of vinyldivinyl monomers in aqueous solutions. Polymers are huge molecules that are encountered in nature as well as in our modern technology.
There are three different types based on the structure of the polymers. Viscoelastic properties of polymers, 3rd edition wiley. The identity and amount of the reagent used to crosslink the polymer chains. Physical properties of polymers include molecular weight, molar volume. General properties of polymers technical properties of normal polypropylene general properties of isotactic. The constituents of a pmc, which affect its overall properties, are 3. Cotton tshirts and plastic spoons do not have much in common with bicycle frames or coffee mugs. The mechanical properties of a polymer involve its behavior under stress. Request pdf physical properties of polymers this thoroughly revised and updated third edition is written by seven wellknown authorities in the polymer science community. Good strengthtoweight ratios for certain but not all polymers. These properties tell a polymer scientist or engineer many of the. The theory is based on a partially permeable sphere model for which we introduce two phenomenological functions, the drag function.
Physical properties of polymers include molecular weight, molar volume, density, degree of polymerization, crystallinity of material, and so on. Concepts of stress and strain described, including the state of stress and components of stress, the state of strain and components of strain. General properties of elastomers elastomer page butyl 2 epdm ethylenepropylenediene modified 3. Thermoplastic polymers are hard at room temperature, but on heating become soft and more or less fluid and can be molded. Polymers have many inherent properties that can be further enhanced by a wide range of additives to broaden their uses and applications. The physical properties of a polymer such as its strength and flexibility depend on. The monomer polymerized or the monomers copolymerized. Elastomers are rubbers or rubberlike elastic materials. General properties of polymers low density relative to metals and ceramics good strengthtoweight ratios for certain but not all polymers high corrosion resistance low electrical and. It is of great importance to be familiar with some basic mechanical properties of the. To obtain linear polymers, the reactants must be bifunctional.
Harris wright state university, dayton, oh 45435 polymers are extremely large molecules that are essential to our very existence. A large molecule macromolecule built up by repetitive bonding covalent of smaller molecules monomers generally not a well defined structure, or molecular weight. The reaction of these two monomers yields a polyester with a somewhat different structure figure 7. Understanding the formation and properties of polymers gives an insight into how they are used in everyday life. The chemistry involved is varied and links together many aspects of the subject including an introduction to organic chemistry, ions, structure and bonding. Properties of polymers, fourth edition incorporates the latest developments in the field while maintaining the core objectives of previous editions. These products are incorporated into floor and wall systems as described in the system bulletins. The commercial grades of nbr are usually blends of nbr with other polymers. The activities that include both practicals and questions help. Today they are an integral part of everyones lifestyle with applications varying from commonplace domestic articles to sophisticated scientific and medical instru. Here you will learn the definition and properties of polymers, another name for. A variety of synthetic polymers as plastic polythene, synthetic fibres nylon 6,6 and synthetic rubbers buna s are examples of manmade polymers extensively used in daily life as well as in industry. General properties of polymers low density relative to metals and ceramics good strengthtoweight ratios for certain but not all polymers high corrosion resistance low electrical and thermal conductivity. From the standpoint of general physical properties, we usually recog nize three types of solid polymers.
Linear polymers these polymers consist of long and straight chains. The reagent used to initiate the polymerization reaction. Introduction of polymers polymer the word polymer is the greek word. Formula of a section of a polyester molecule formed by polycondensation. They are a main constituent of our food starch, protein, etc. Characteristics, applications and properties of polymers springerlink. A description of these individual products and its typical physical properties is. It is chemically synthesised from ethylene, a compound that is usually derived from petroleum or natural gas.
General design principles for dupont engineering polymers. In order to assess the most suitable matrix polymer, one must know the properties of the available polymers. Monomers repeat units the identity of the monomer residues repeat units comprising a polymer is its first and most important attribute. Mechanical properties of polymers like tensile strength, toughness, elasticity depends upon intermolecular forces like vander waals forces and hydrogen. For that, in this article, i am exploring the necessary properties of polymers in a detailed manner.
Viscoelastic behavior reflects the combined viscous and elastic responses, under mechanical stress, of materials which are intermediate between liquids and solids in character. If you are after basic information on plastic materials, this is the place to find it. Chemists have also learned to synthesize new polymers from simple chemicals, creating a vast array of plastics and synthetic fibers. Polymers or macromolecules are very large molecules made up of smaller units called monomers or repeating units, covalently bonded together.
112 806 896 162 441 138 344 1385 455 1283 375 855 545 344 1355 645 781 1432 1181 318 763 439 556 1239 758 1005 726 870 528 483 935 1484 42 623