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.
Figure:
spaced –CONH– amide groups. Nylon 6-6, or poly(hexamethylneadipamide), is composed of. two structural monomers (hexamethylendiamine (H2N(CH2)6NH2) and adipic acid. (HOOC(CH2)4COOH), whereas Nylon 6, or poly(6-caprolactam), is composed of a single structural unit (either 6-aminocaproic acid (H2N(CH2)4COOH) or caprolactam). Ultimately, the answer is yes.
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
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.
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).
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
Kevlar fiber is therefore a “Polyaromatic amide”, as it has a high breaking strength. 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.
(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).
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.
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
Mordred would always be at his most comfortable in the forest, having been raised as a Druid for much of his life. Yet there was something about Camelot he adored above all other places – not the bustling activity that marked its sunny days, but the ethereal silence which blanketed the city late at night, the soft glow of moonlight bathing the towers of the Citadel as its inhabitants slept peacefully beneath the velvet firmament.
PostText1: Annealing allows plastic to "bend" like the proverbial willow tree, instead of breaking like the proverbial oak.
This maximises the intermolecular forces between the chains as they are able to pack closely together. However, this reduces the flexibility and is therefore quite rigid and strong. This isotactic polyvinyl chloride structure occurs very little. Another structure that is produced very little is the syndiotactic PVC. The syndiotactic PVC has a regular arrangement and has similar properties of flexibility, rigidity and strength to the isotactic PVC as shown in Figure #.
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...
Polyethylene is a polymer that is made of a long chain of CH2 monomers bonded together. It is one of the most commonly used polymers in everyday items. Grocery bags, soap bottles, children’s toys, and even bullet proof vests are all made from polyethylene.2 This polymer is very versatile and can be used in many materials but this all depends on the way that the polymer is chemically made or enhanced. There are many different types of polyethylene classified by density and branching. 2