Polymer Basics Polymers are made up of chains of smaller molecules called monomers. A biological example is protein which is made up of amino acids. Most plastics are derived from petroleum products. The physical and chemical properties of a polymer depend on the monomer that it is made of. Some differences between plastics can be seen, felt or
Polymers. The word "Polymer" is derived from two Greek words, 'Poly' that means many (numerous) and 'Mer' which means units. In basic terms, a polymer is a long-chain molecule that is composed of a large number of repeating units of identical structure. These identical structures, we understand as a unit made up of two or more molecules, join together to form a long chain.
Polymers are all created by the process of polymerization wherein their constituent elements called monomers, are reacted together to form polymer chains, i.e 3-dimensional networks forming the polymer bonds. The type of polymerization mechanism used depends on the type of functional groups attached to the reactants.
Natural Polymers are those substances which are obtained naturally. These polymers are formed either by the process of addition polymerization or condensation polymerization. Polymers are extensively found in nature. Our body too is made up of many natural polymers like nucleic acids, proteins, etc. The Cellulose is another natural polymer ...
Many polymers display another type of localized yielding behavior which results in whitening of the polymer in the region of maximum deformation. Under a microscope, these localized regions of yielding display an increase in volume (dilatation) through formation of micro-cracks which are bridged by polymer …
Polymers are large molecules that are formed by joining two smaller molecules called the monomers. These macromolecules are present in virtually everything that surrounds us. There are two types of polymers: Natural polymers : They are those found in nature. Among them are: DNA, starch, silk and cellulose . Artificial polymers : They are those polymers that require the intervention of the ...
By changing the monomer, they created polymers with other characteristics. One of them is a self-healing organogel. "Trapped inside a polymer metric, you have an OH group capable of hydrogen bounding," says Garcia. "When you cleave the gel and separate it and then put it together, those hydrogen bonds re-form." Polymer Possibilities
Polymer chains can include hundreds of thousands of atoms — even millions. The longer a polymer chain, the heavier it will be. And, in general, longer polymers will give the materials made from them a higher melting and boiling temperature. Also, the longer a polymer chain, the higher its viscosity (or resistance to flow as a liquid). The ...
Thermoset polymers haven't melting point. The degree of crystalinity is the main factor, affect on melting point of polymers. Symmetry, intermolecular forces, tacticity, branching and molar mass of polymer chains also greatly affect to the melting point of polymers; PTFE has the highest melting point among all polymers.
Most polymers will undergo significant changes over time when exposed to heat, light, or oxygen. These changes will have a dramatic effect on the service life and properties of the polymer and can only be prevented or slowed down by the addition of UV stabilizers and antioxidants. The degradation of polymers can be induced by
Properties of a Polymer: Most of the products we use in our daily life are polymers, such as synthetic clothes, plastic bags, Teflon, cookwares, rubber products, and many more. Polymers can be defined as any class of natural or synthetic substances built from significantly large molecules, called macromolecules that are manifolds of simpler chemical units known as monomers.
Basic Polymer Structure. There are four basic polymer structures which are shown in the figure below. In practice, some polymers might contain a mixture of the various basic structures. The four basic polymer structures are linear, branched, crosslinked, and networked. Diagrams of linear, branched, crosslinked, and networked polymer structures.
Worldwide changes in industrial polymer production often make it necessary to find and qualify a new source of polymer material. DSC is an ideal method for investigating the quality of new stocks of material and for comparing lot-to-lot variations in the following properties: Tg (softening/flow), melting, crystallization and percent crystallinity.
A polymer (/ ˈ p ɒ l ɪ m ər /; Greek poly-, "many" + -mer, "part") is a substance or material consisting of very large molecules, or macromolecules, composed of many repeating subunits. Due to their broad spectrum of properties, both synthetic and natural polymers play essential and ubiquitous roles in everyday life. Polymers …
What are polymers? Polymers are substances composed of macromolecules, very large molecules with molecular weights ranging from a few thousand to as high as millions of grams/mole. The IUPAC Gold Book definition of a macromolecule is: "A molecule of high relative molecular mass, the structure of which essentially comprises the multiple ...
Minimization of Wear of Polymers by Plasma Treatment • Crystalline polymers: HDPE, POM • Amorphous polymers: PMMA, PC • CASING (Cross-linking by activated species of inert gases) • Helium plasma (1 torr, 13.56 MHz, 100 Watts, Room temp.) for 500 and 1000 seconds • Pin-on-disk, Normal load = 4.4 N, speed = 3.3 cm/s
The term polymer is commonly used in the plastics and composites industry, often as a synonym for plastic or resin.Actually, polymers include a range of materials with a variety of properties. They are found in common goods, in clothing and toys, in construction materials and insulation, and in numerous other products.