POLYMERS : PLASTICS AND THERMOPLASTICS

sahilnagpal79025 10,625 views 65 slides Apr 13, 2015
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About This Presentation

POLYMERS : PLASTICS AND THERMOPLASTICS


Slide Content

POLYMERS: PLASTICS AND RUBBER MADE BY $ ahil Nagpal (Coordinator ) B.COM(HONS) 232 Date Of Submission

PLASTIC A plastic material is any of a wide range of synthetic or semi-synthetic organic solids that are moldable. Plastics are typically organic polymers of high molecular mass, but they often contain other substances. They are usually synthetic, most commonly derived from petrochemicals but many are partially natural.

Plastics History First Plastic - Parkesine The first man-made plastic was created by Alexander Parkes who publicly demonstrated it at the 1862 Great International Exhibition in London. The material called Parkesine was an organic material derived from cellulose that once heated could be molded, and retained its shape when cooled.

Snapshots of some Parkesine Materials (First Plastic)

Celluloid is derived from cellulose and alcoholized camphor. John Wesley Hyatt invented celluloid as a substitute for the ivory in billiard balls in 1868. He first tried using collodion a natural substance, after spilling a bottle of it and discovering that the material dried into a tough and flexible film. However , the material was not strong enough to be used as a billiard ball, until the addition of camphor, a derivative of the laurel tree. The new celluloid could be molded with heat and pressure into a durable shape.

Snapshot of Billiard Balls Made After Enhancing Parkesine

Formaldehyde Resins - Bakelite After cellulose nitrate, formaldehyde was the next product to advance the technology of plastic. Around 1897, efforts to manufacture white chalkboards led to casein plastics (milk protein mixed with formaldehyde) Galalith and Erinoid are two early tradename examples . In 1899, Arthur Smith received British Patent 16,275, for "phenol-formaldehyde resins for use as an ebonite substitute in electrical insulation", the first patent for processing a formaldehyde resin.

In 1899, Arthur Smith received British Patent 16,275, for "phenol-formaldehyde resins for use as an ebonite substitute in electrical insulation", the first patent for processing a formaldehyde resin. However, in 1907, Leo Hendrik Baekeland improved phenol-formaldehyde reaction techniques and invented the first fully synthetic resin to become commercially successful, tradenamed Bakelite.

Snapshot of Materials made from Bakelite

Timeline - Precursors 1839 - Natural Rubber - method of processing invented by Charles Goodyear 1843 - Vulcanite - Thomas Hancock 1843 - Gutta-Percha - William Montgomerie 1856 - Shellac - Alfred Critchlow , Samuel Peck 1856 - Bois Durci - Francois Charles Lepag

Timeline - Beginning of the Plastic Era with Semi Synthetics 1839 - Polystyrene or PS discovered - Eduard Simon 1862 - Parkesine - Alexander Parkes 1863 - Cellulose Nitrate or Celluloid - John Wesley Hyatt 1872 - Polyvinyl Chloride or PVC - first created by Eugen Baumann 1894 - Viscose Rayon - Charles Frederick Cross, Edward John Bevan

Timeline - Thermosetting Plastics and Thermoplastics 1908 - Cellophane ® - Jacques E. Brandenberger 1909 - First true plastic Phenol-Formaldehyde tradenamed Bakelite - Leo Hendrik Baekeland 1926 - Vinyl or PVC - Walter Semon invented a plasticized PVC. 1927 - Cellulose Acetate 1933 - Polyvinylidene chloride or Saran also called PVDC - accidentally discovered by Ralph Wiley, a Dow Chemical lab worker. 1935 - Low-density polyethylene or LDPE - Reginald Gibson and Eric Fawcett 1936 - Acrylic or Polymethyl Methacrylate

1937 - Polyurethanes tradenamed Igamid for plastics materials and Perlon for fibers . - Otto Bayer and co-workers discovered and patented the chemistry of polyurethanes 1938 - Polystyrene made practical 1938 - Polytetrafluoroethylene or PTFE tradenamed Teflon - Roy Plunkett 1939 - Nylon and Neoprene considered a replacement for silk and a synthetic rubber respectively Wallace Hume Carothers 1941 - Polyethylene Terephthalate or Pet - Whinfield and Dickson 1942 - Low Density Polyethylene 1942 - Unsaturated Polyester also called PET patented by John Rex Whinfield and James Tennant Dickson 1951 - High-density polyethylene or HDPE tradenamed Marlex - Paul Hogan and Robert Banks 1951 - Polypropylene or PP - Paul Hogan and Robert Banks

1953 - Saran Wrap introduced by Dow Chemicals. 1954 - Styrofoam a type of foamed polystyrene foam was invented by Ray McIntire for Dow Chemicals 1964 - Polyimide 1970 - Thermoplastic Polyester this includes trademarked Dacron, Mylar, Melinex , Teijin, and Tetoron 1978 - Linear Low Density Polyethylene 1985 - Liquid Crystal Polymers

Plastic Products 1.Plastic Garbage Bags A bin bag or bin liner or garbage bag , or trash bag (American English) is a disposable bag used to contain rubbish (British English) or trash (American English).

SILLY PUTTY Silly Putty is a toy based on silicone polymers which display unusual physical properties. It bounces, but breaks when given a sharp blow and can also flow like a liquid. It contains a viscoelastic liquid silicone, a type of non-Newtonian fluid, which makes it act as a viscous liquid over a long time period but as an elastic solid over a short time period.

VELCRO Velcro is a company that produces the first commercially marketed fabric hook-and-loop fastener typically , two lineal fabric strips. The first component features tiny hooks; the second features even smaller and "hairier" loops. When the two components are pressed together, the hooks catch in the loops and the two pieces fasten or bind temporarily. When separated, by pulling or peeling the two surfaces apart, the velcro strips make a distinctive "ripping" sound.

Types Of Plastics The response of a polymer to mechanical forces at elevated temperature is related to its dominant molecular structure. One classification of polymers is according to its behavior and rising temperature. Thermoplastics and Thermosets are the 2 categories. A THERMOPLASIC is a polymer that turns to a liquid when heated and freezes to a very glassy state when cooled sufficiently. Most thermoplastics are high-molecular-weight polymers whose chains associate through weak Van der Waals forces (polyethylene); stronger dipole-dipole interactions and hydrogen bonding (nylon).

Snapshots of Thermoplastics

Examples of Thermoplastics

More Examples of Thermoplastics

The effect of Temperature on the Structure and Behavior of Thermoplastics ©2003 Brooks/Cole, a division of Thomson Learning, Inc. Thomson Learning ™ is a trademark used herein under license.

Thermoplastic polymers differ from thermosetting polymers (Bakelite, vulcanized rubber) since thermoplastics can be remelted and remolded. Thermosetting plastics when heated, will chemically decompose, so they can not be recycled. Yet, once a thermoset is cured it tends to be stronger than a thermoplastic. Typically, linear polymers with minor branched structures (and flexible chains) are thermoplastics. The networked structures are Thermosets .

Snapshots of Thermosetting Plastics

Thermoset Data

Structure Of Thermoplastics and Thermosets

Thermoplastic v/s Thermosetting Plastic Thermoplastic Thermosetting Plastic Little Cross Linking Large Cross Linking Ductile Hard and Brittle Soften with Heating Doesn’t Soften with Heating E.G.-Polyethylene, Polypropylene, Polycarbonate, Polystyrene . E.G.-Vulcanized Rubber, Epoxies, Polyester Resin, Phenolic Resin.

Manufacturing Of Plastic Acquiring the raw material or monomer.

Synthesizing the basic polymer .

Compounding the polymer into a material that can be used for fabrication.

Molding or shaping the plastic into its final form.

Properties Of Plastics Lightweight   Resistance to breakage  Insulating capacity (electrical, thermal and acoustic )  Ease of handling and safety  Versatility   Recyclability   Usefulness   Simple , cheap manufacturing  Impermeability (water, light, gases)  Does not conduct electricity (excellent for cables, plugs)        

Advantages It is cheap and easy to buy. Hard plastics can be used in making chairs, toys etc. Can be putted in other materials and strengthens them. Easy to clean and hard to break, you can use it to store water and food. Can be used in all types of season and weather even if its summer or raining. Can be recycled into another product. Can be used in surgeries.

Disadvantages It takes a hundred of years to decompose. Hard to dispose properly. It is made from nonrenewable resources of Earth. Can’t stand up because of its lightness. Are not biodegradable. Number one flood causing material . Recycling is very Expensive.

Recycling Plastic Plastic recycling is a process in which old plastics is turned into another more useful products. Since plastics can be considered indestructible or simply does not break down easily. It is also the number one trash of humans in landfills which took a lot of space. One way to reduce it is to recycle. From the word recycling itself I know you have already an idea what will they do to it. The plastics are brought back to the factories where they do recycling and turned to another products. Some can be turned into trashcans, pots, papers and many more.

Process of Recycling Plastic

Types Of Recycling Processes Mechanical Recycling The recycling in which plastics are grouped, then melted, shredded and molded into new shapes creating a new product . Chemical Recycling The recycling in which plastics are melted altering some chemical properties to create a new product.

Biodegradable Plastics This is the another way to solve our environmental problems from plastics, this replaces the non-biodegradable plastics into new breed called bioplastic . These breed of plastics are commonly made from plants such as corn starch, cane sugar, potato starch and native wild grasses. It also helps reducing the use of nonrenewable resources of Earth by using renewable ones which benefits both humans and nature. Disposing it properly is the best way to help in reducing pollution and minimizing the dependence on fossil fuels.

Process of Recycling Biodegradable Plastic

Plastic Recycling Symbols In 1988 the Society of the Plastics Industry developed a numeric code to provide a uniform convention for different types of plastic containers. These numbers can be found on the underside of containers. 1. PET; PETE (polyethylene terephthalate): plastic water and Soda bottles. HDPE (high density polyethylene): laundry/dish detergent V (Vinyl) or PVC: Pipes, shower curtains LDPE (low density polyethylene): grocery bags, sandwich bags PP (polypropylene): Tupperware®, syrup bottles, yogurt cups, PS (polystyrene): Coffee cups, disposable cutlery Miscellaneous: any combination of 1-6 plastics

Rubber Rubber can be described in two ways :- Natural rubber is a substance obtained from the milky juice, called latex, produced by a number of different kinds of plants. Synthetic rubber, made by various chemical manufacturing processes, is similar to natural rubber.

Natural Rubber Natural rubber , also called India rubber or, as initially produced, consists of suitable polymers of the organic compound isoprene, with minor impurities of other organic compounds plus water . Currently, rubber is harvested mainly in the form of the latex from certain trees. The latex is a sticky, milky colloid drawn off by making incisions into the bark and collecting the fluid in vessels in a process called "tapping".

The latex then is refined into rubber ready for commercial processing. Natural rubber is used extensively in many applications and products, either alone or in combination with other materials. In most of its useful forms, it has a large stretch ratio, high resilience, and is extremely waterproof .

Structure Of Natural Rubber

Process of Making Natural Rubber 1. Latex Is Extracted from Trees.

2. Liquid Latex Extracted Is Poured Into a Tray with Spikes So That after Drying Latex can Be easily taken out.

3.The Tray is then put in a Latex Hardening And Drying Machine (LHDM)

4. After Hardening and Getting Dried The Latex We get a Cuboid Of Natural Rubber.

Synthetic Rubber Synthetic rubber is created from petroleum and is classified as an artificial elastomer. This means that it is able to be deformed without sustaining damage, and can return to its original shape after being stretched. Synthetic rubber has many advantages over natural rubber, and is used in many applications due to its superior performance. The use of synthetic rubber is much more prominent than natural rubber in most industrialized nations.

Process of Making Synthetic Rubber Crude Oil is Extracted.

Two gases called butadiene and styrene are produced as byproducts during the petroleum refining process .

Liquid latex, a basic form of synthetic rubber, is created when butadiene and styrene are properly combined .

After liquid latex is allowed to dry, it can be formed into different shapes and used by manufacturing facilities in place of natural rubber.

Uses of Rubber Used as Tyres In Automobiles and Airplanes.

Used as Insulators in Electrical Equipments .

Used In Shoes, Stationery, Other Lifestyle products etc.

Properties of Rubber Physical Properties Non reactive Chemically Resistant to many fluids including many water, weak acids & alkalis Non conductive Poor conductor of heat & electric Elastic Tough Electric resistant Electric insulator

Chemical Properties Polymers Consists of isoprene molecules fitted together in loosed chains Consisting long chains of one or more type of molecules Contain long chains of hydrogen and carbon molecules Rubber go through vulcanization through adding sulfur which result in a hard, durable material with great mechanical properties. This create a chemical links between the chains.

Advantages Of Rubber Rubber is not only elastic, but is also waterproof and is a good electrical insulator. Natural rubber is resilient and is resistant to tearin . Some types of rubber are resistant to oils, solvents, and other chemicals. SBR (STYRENE BUTADIENE RUBBER) RUBBER provides good abrasion, wear, and tensile qualities. Rubber is resistant to ozone, sunlight, oxidation and many petroleum derivatives.

It also exhibits excellent resistance to ozone, oxidants, and severe weather conditions, thereby making it an outstanding material for outdoor applications. Other characteristics include excellent color stability, heat resistance, and dielectric qualities.

Disadvantages Of Rubber Low-cost latex products generally shrink . Making molds with latex rubber is slow and time-consuming . Latex molds are generally not suitable for casting resins.  Has offensive odour . Silicones are generally high in cost . They are also sensitive to substances, and do not have a long library life . Polysulfide rubber costs higher than latex.

Needed to cleaned it often to be kept clean. Detergent & other abrasive cleaning liquid which may discolor surface. Grease will have a drastic negative effect if not wiped up.

Recycling Rubber Why reclaim or recycle rubber? Rubber recovery can be a difficult process. There are many reasons , however why rubber should be reclaimed or recovered ; Recovered rubber can cost half that of natural or synthetic rubber. Recovered rubber has some properties that are better than those of virgin rubber. Producing rubber from reclaim requires less energy in the total production process than does virgin material. It is an excellent way to dispose of unwanted rubber products, which is often difficult.

It conserves non-renewable petroleum products, which are used to produce synthetic rubbers . Recycling activities can generate work in developing countries. Many useful products are derived from reused tyres and other rubber products. If tyres are incinerated to reclaim embodied energy then they can yield substantial quantities of useful power. In Australia, some cement factories use waste tyres as a fuel source .