INTRODUCTION
What is polymer?
The term name of polymer came from ancient greek, poly and mers meaning many parts. Polymer consist a very large molecule comprising hundreds or thousands of atoms formed by successive linking of one or two, occasionally more, types of small molecule in chain or network structures. In Fig 1, this specific molecular structure (chainlike structure) of polymeric materials is responsible for their intriguing mechanical properties. Polymer architecture can vary.
Figure 1: A polymer chain.
In Fig 2 three possible molecule architectures are depicted. A linear polymer consists of along chain of monomers. A branched polymer has branches covalently attached to the main chain. Cross-linked polymers have monomers
POLYMER PROPERTIES / BEHAVIOR There is several properties analysis of polymer. In this topic, we will discuss further the five polymer properties and behavior. Mechanical properties / Behavior. Thermal properties / Behavior. Melting properties / Behavior. Electrical properties / Behavior. Optical properties / Behavior
Mechanical properties / Behavior
The mechanical properties of a polymer involve its behavior under stress. These properties tell a polymer scientist or engineer many of the things he or she needs to know when considering how a polymer can be used. How strong is the polymer? How much can we stretch it before it breaks? How stiff is it? How much does it bend when push on it? Is it brittle? Does it break easily if hit it hard? Is it hard or soft? Does it hold up well under repeated stress? The mechanical properties of polymers are one of the features that distinguishes them from small molecules.
In figure 3.1 the tensile strength is the stress needed to break a sample. It is expressed in Pascals or psi (pounds per square inch). 1 MPa = 145 psi. The tensile strength is an important property for polymers that are going to be stretched. Fibers, for instance, must have good tensile strength.
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Carbon is one of the 115 chemical elements discovered on Earth which is part of the nonmetals group with other elements such as nitrogen, oxygen, and hydrogen. Carbon as an element has good stability, it is very light, very stable, and has many types of forms such as graphite, and coal. Carbon fiber is just another form of carbon, basically has filaments between five to ten micrometers in diameter of pure carbon or at least 90% of carbon. Thousand carbon fibers are twisted together to form a long chain, which can then be used in a variety of raw forms, including yarns, weaves, and braids, which are in turn mixed with synthetic resins to create the carbon fiber as a composite material. Based on different characteristics carbon fibers can be divided into three principals groups: according to carbon fiber tensile modulus, according to precursor fiber materials, and according to final heat
(A) A monomer showing the central α-helix flanked by N-terminal and C-terminal regions. (B) Dimer of two monomers are coiled coil with a length of 48nm. (C) Assembly of antiparallel dimers forming a staggered tetramer. (D) Two tetramers are linked together. (E) The 10nm-intermediate filament is composed of twisted eight tetramers. Figure adapted from Alberts et al., 2008).
The first term that I noted during the movie was Conductive Polymers. Conductive polymers are almost always organic meaning a large class of chemical compounds whose molecules contain carbon. These polymers have extended delocalized bonds which are bonds found in a molecule that do not belong to a single atom or covalent bond. They are conjugated systems of double bonds and in a aromatic systems. The conjugated systems are atoms covalently bonded with alternating single and double bonds. When the electrons are removed or added into the valence bands the electrical conductivity increases. The conductive polymer has a low conductivity until the electron is removed from the valence band called (p-doping) or (n-doping) until it becomes more conductive. The movement of the charges is what is responsible for electrical conductivity. These polymers are plastic which are organic polymers and with mechanical properties such as flexibility and elasticity.
Polymer creatures are very fascinating, because they can grow when put in liquids, and experiments are going to be conducted relating to this growing. A polymer is a very long chain of molecules strung together (What). Polymers are very versatile, and can have almost limitless colors and characteristics (Definition). One of these qualities is absorbency, and some can absorb as much as five hundred times their weight in water (Growing). It is hypothesized that if the polymer creatures are submerged in water for a day it will at least double in size, while it will not grow as much when put in Sprite.
Polymer chains are long, individual chains, although they behave as if they are attached to each other. The individual chains are actually held together by ‘Electrostatic Forces’ between molecules, also known as ‘Hydrogen Bonds’. Scientists discovered this, by using a special type of X-ray microscopy called ‘XANES’. This was able to reveal the orientation of molecules in materials. It has also been discovered that the components of Kevlar fiber, have a radial orientation that is in a crystal. The crystal-like regularity is the largest contributing factor in the strength of Kevlar fiber.
It is a kind of plastic that originates from consolidating ethylene (found in unrefined petroleum) and chlorine (found in salt). At the point when joined together these substances get to be Polyvinyl Chloride (PVC) gum, or as it is better known - Vinyl. It is then further handled to be made more adaptable, inflexible, semi-fluid, clear or bright, thick or thin.
Most of the necessities humans need are provided in supermarkets, in fact supermarkets have become a necessity for our everyday life. They are now the main source of water, food, clothes and everyday tools. Therefore, the plastic bags demanded and supplied in this industry increase every day. In the past decade, we produced as much plastic as we did in the whole twentieth century (Freinkel, 2011). This exponential increase of a non-biodegradable material has negatively impacted our environment immensely. Plastic production requires our dwindling fossil fuel resources, robs away animal lives, litters our beautiful landscapes and even affects our very own well-being. Hence, if plastic production doesn’t diminish immediately, we will suffer great
PostText1: Annealing allows plastic to "bend" like the proverbial willow tree, instead of breaking like the proverbial oak.
The synthesis of polymers starts with ethylene, (or ethene). Ethylene is obtained as a by-product of petrol refining from crude oil or by dehydration of ethanol. Ethylene molecules compose of two methylene units (CH2) linked together by a double carbon
however, is a synthetic fiber. It is a polyamide whose molecular chains are formed by regularly
How are ionic and covalent bonding similar? How are they different? You should discuss how they bond and what the major differences are in their nomenclature (the way they are named).
The purpose of this experiment was to create a polymer by reacting a mixture of decanedioyl dichloride and dichloromethane with a mixture of water, 1,6-hexadiamine and sodium carbonate. Specifically, we created the polymer Nylon-6,10. Nylon-6,10 polymers are used in a vast majority of things we use in everyday life such as zippers, the bristles in brushes, and even car parts. This experiment was different from the industrial method of making nylon because that takes place at a much higher temperature. A polymer is a substance that has a structure made of similar or identical units bonded together. All polymerizations fall into two categories: step-growth and chain-growth (both of which we used to form our polymer). Step growth polymerization
Polymer-Polyethylene is partially crystalline as well as amorphous because it has crystalline and amorphous regions. Also it has linear chains so this is the simplest structure compared to a branched or network chain. This can be of an advantage to it over other types of materials as its good toughness and elongation makes it very significant in the engineering industry as it can be moulded or extruded into shape...
chains instead of hydrogen atoms. Cross-linking is another way in which the polymer can be made stronger. This involves ultraviolet radiation that bombards the polymer with electrons and formulates bonds between the molecular chains of the polymers. This is like linear polyethylene but different in that it is more impact resistant, and it has a much higher density. This allows it to be stored or be used with different chemicals that would normally cause the polymer to desolve.3 This can start to become a problem because as the polymer continues to become chemically enhanced. So the ways of dissolving and recycling the polymer become more difficult.