Thermoplastics have the simplest molecular structure, with chemically. The name plastic is derived from the greek word plastikos, which means able to be shaped. Feb 25, 20 matching activity suitable for ks4 students to learn different names, properties and uses of plastics. Polymers are studied in the field of biophysics, macromolecular science, and polymer science. Hdpe products are very safe and are not known to leach any chemicals into. Some plastics can be recycled their properties can be chemically manipulated to create a new plastic object that may serve a different function than that of the original object. Despite their harmfulness, in many cases the most hazardous substances in plastics are not the monomers but other compounds, such as solvents, initiators, catalysts and other polymerization additives. Bridging the gap between theory and practice, it enables scientists to understand the commercial implications of their work as well as providing technologists with a theoretical background.
Typical reactions for chain assembling are polyaddition continuous or step wise and condensation polymerization polycondensation 1 figure 1. Typical reactions for chain assembling are polyaddition continuous or step wise and condensation polymer ization polycondensation 1 figure 1. Types of plastics their physical properties processing methods. Take a few minutes to look around the room and identifysome.
For example some solvents may be toxic and flammable, and they can sometimes be hard to completely evaporate or precipitate from the polymer when. Linear polymers and a combination of linear and cross. Plastics and their properties the laboratory people. Since the previous edition, several new materials have been. Same test as ul 94 v1, but the test samples emit burning particles during the test.
Heating hydrocarbons oil, natural gas or coal produces plastics. The plastic stays out of shape when deformed and typically decompose before they melt. The two main types of plastics are called thermosetting plastics and thermoplastics. The properties of a plastic are determined by the length of the plastics. It can be used to create rigid, lightweight sheets, like foamex, but it can also be used to make fauxleather materials like leatherette and pleather. Dissolved in solvents or dispersed as emulsions, they are used in paints, varnishes and adhesives. The preparation of mixtures of nonbiobased polymer as pe and biobased polymer as chitosan, represent a simple way to combine their best properties, in order to obtain materials with good. Carbon black is sometimes added to plastics to protect from ultraviolet radiation. The success of plastic as an engineering material will depends up on the selection of variety of plastic. While it is most o en thought of as fracture, failure occurs in many other ways section 1.
Taking that a step further, the variation within the properties demonstrated by different plastics arises from diversity in their structure. Mechanicalpropertiesof polymers kamyardavoudi october,20 materialsscienceseminar. Number 7 is for all plastics other than those identified by number 16 and also plastics that may be layered or mixed with other types of plastics, such as bioplastics. Other plastics such as pet, pp, hdpe, pa12, pa11, pa6, pes. The following plastics chart supplied by nalgene, includes all of the plastics mentioned in this document. Scientific properties, such as density, modulus and transparency, which reflect fundamental atomic and. Plastics now comprise nearly 70 of the synthetic chemical industry in the nation. Thermoset plastics tend to be rigid and have high molecular weights. This is a simple drag and drop exercise, giving a very general background to the origins of most plastics. The polymers polyethylene, polypropylene, polybutylene, polystyrene and polymethylpentene are made up of only. The most common type of plastic is polyethene, which is a. The plastics after this change continue to interact. These additives affect the chemical composition, properties, and mechanical properties of plastics and affect its cost.
Information on thermoplastics, thermosets, raw materials and biobased and degradable polymers with muliple links to each polymer type. Jun 10, 2017 polymer is a chemical compound in which the molecules are bind together in long repeated chains. Plastics start to become brittle at temperatures below zero. Biodegradable plastics are also very costly to produce, and take away too long to degrade anyway. In terms of properties, pvc is one of the most versatile. The development of plastics has come from the use of natural plastic materials and since. At consolidated plastics, we mold polyethylene into a variety of highquality packaging and container products.
Caused by the macromolecular structure and the temperature dependent physical properties plastic materials are distinguished into different. Once cooled and hardened, these plastics retain their shapes and cannot return to their original form. The suitability of products intended for use in these temperature ranges should be tested prior to application. Unmodified types of plastics that are regarded as having unacceptable resistance to uv are pom acetal, pc, abs and pa66. The special properties of plastics such as low density, low electrical conductivity, transparency, and toughness allow plastics to be made into a wide variety of products. Manufacturers place an spi code, or number, on each plastic product, usually moulded into the bottom. The development of plastics has come from the use of natural plastic materials and since plastics are environmentalfriendly they have been.
Thermosetting plastics, once heated and cooled, cannot be reheated and remolded. The aim is to give engineers and technologists a sound understanding of basic principles without the introduction of unduly complex levels of mathematics or chemistry and thereby set plastics in their proper context as engineering materials. Other types of thermoplastics include nylon, pvc and pva. In the development of plastic enclosures and tuning knobs, the designers follow the ecodesign directive. For example, our oblong and round jugs are made of high density polyethylene hdpe. Objective to identify the six kinds of recycled plastic polymers by measuring their physical and chemical properties. The smaller molecules are those such as ethylene ethane, c 2 h 4. Users are to test for themselves if autoclaving may have any effect on other characteristic product features so as to influence the individual application concerned. This chart gives many useful ratings pertaining to these plastics including temperature tolerances, permeability and sterilization processes. Examples include polyurethanes, polyesters, epoxy resins and. The size and structure of the polymers that compose different plastics contribute to the plastics properties. They are also known to return to their original form.
The term plastics describes a group of chemicals called polymers. The spi code of 2 identifies plastic made with highdensity polyethylene, or hdpe. Examples of thermoset plastics include epoxy, polyester, acrylic resins, polyurethanes, and vinyl esters. Properties of plastic materials combustibility test for plastics according to ul subject 94 the plastic materials are classified as follows. The plastics design library series pdl is a collection of data books, reference works and practical guides covering plastics engineering, applications, processing, manufacturing, material selection, product design, recycling and waste, and innovative materials. This book presents in a single volume the basic essentials of the properties and processing behaviour of plastics and composites. The uses depend on the properties of each resin listed e.
Chapter 5 properties of plastics mechanical and physical properties of plastics this section will acquaint the reader with the technical terms and concepts used to describe the properties or performance of a material. The density of a plastic sample may change due to change in crystallinity, loss of plasticizers, absorption of solvent, etc. While many pure plastics cannot absorb uv radiation, the presence of catalyst residues and other impurities will often act as free radical receptors, and degradation occurs. It is calculated by dividing the mass of the material by the volume and is normally expressed in gcm 3. Different types of plastics and their classification the society of the plastics industry spi established a classification system in 1988 to allow consumers and recyclers to identify different types of plastic. Plastics that can be deformed easily upon heating and can be bent easily. These are the types of plastics that are less rigid.
Linear polymers and a combination of linear and crosslinked polymers come under thermoplastics. View plastic materials found under a specific property group. Plastic materials consist of long chain molecules polymers. The most common type of plastic is polyethene, which is a thermoplastic. The seventh edition of this classic reference work once more provides a comprehensive overview of commercially available plastics materials. We recognize five different types of polymer properties.
The plastic properties on pages 222223 are exclusively applicable for the specified standard test pieces. Plastics are extremely diverse in terms of chemical composition, properties and possible. Available in many colors and in transparent form, plastics can be rubbery or rigid. Plastics are hazardous for human health and the environment. It is important to understand these standard terms since they are used by suppliers and users to communicate how a material. This process is called cracking because a catalyst is used to break larger molecules into smaller ones. Physical properties of plastics material formula density g cm3 flammability limiting oxygen index % optical transmission % radiation resistance refractive index resistance to ultraviolet water absorption % water absorption equilibrium % water absorption over 24 hours %. The polymer used in making a plastics are usually a combination of additives, colorants, plasticizers, stabilizers, fillers, and reinforcements. Plastics are a wide range of synthetic or semisynthetic organic compounds that are malleable and so can be molded into solid objects plasticity is the general property of all materials which can deform irreversibly without breaking but, in the class of moldable polymers, this occurs to such a degree that their actual name derives from this specific ability. Also, the fuel to run a recyclable collection program and to run the melting processing. Items made from this plastic are commonly recycled. Resins are any of the chemically modified natural resins or synthetic polymers which are physically similar, including thermoplastic materials such as polyvinyl, polystyrene, and polyethylene, as well as thermosetting materials such as polyesters, epoxies, and silicones.
T he characteristic properties exhibited by plastics are the direct result of the unique molecular structure of these materials. As a result, polyethylene is in a wide variety of products. Properties and uses of plastics as a construction material. Matching activity suitable for ks4 students to learn different names, properties and uses of plastics.
These are the types of plastics that are used in aircraft parts, tires, and many others. The divisions between grades in terms of their property characteristics are quite fundamental to the classification of plastics materials problem of modelling plastics materials. The two types of plastics are thermoplastics and thermosetting polymers. July 26, 20 august 2, 20 karen lemon leave a comment. Examples of thermosetting plastics are silicones, urea aldehyde and bakelite. To summarize, there are 7 types of plastic exist in our current modern days. Colorants are added to produce a wide array of colors in plastics. Each plastic material has its own peculiar properties to suit its particular uses. Feb 26, 2012 polymers and their properties introduction basic topics. Chemically the polyamides are divided into two types.
Pet e plastic is used to make many common household items like beverage bottles, medicine jars, rope, clothing and carpet fibre. Each different density of polyethylene gives the final plastic unique physical properties. Sometimes, plastics may affected by termites and rodents especially in the case of thermoplastic types, however it is not a serious problem because of no nutrition values in plastic. Variations may occur as far as cases and technical parts are concerned. Using pigments plastics of any attractive colour can be produced. Physical properties of plastics material formula density g cm3 flammability limiting oxygen index % optical transmission % radiation resistance refractive index resistance to ultraviolet water absorption % water absorption equilibrium % water absorption over 24 hours. Background information every polymer has very distinct characteristics, but most polymers have the following general attributes. Polymers and their properties introduction basic topics. This resin chart describes six common resins and the variety of uses each has. These plastics are to be kept in moulds till cooling takes place completely. Bakelite, kevlar, and vulcanized rubber are also thermoset plastics.
Some properties of plastics include their light weight, high resistance to various chemicals, thermal and electrical insulation and their wide range of colors, characteristics and potential uses. The different types of plastics and their classifications. Polycarbonate pc is used in baby bottles, compact discs, and medical storage containers. Plastics are manufactured in different forms such as moulding pipes, sheets and films. Depending on physical properties, plastics are divided into two types.
Thermosets can be used for auto parts, aircraft parts and tires. Polymer is a chemical compound in which the molecules are bind together in long repeated chains. They are formed or expanded to produce materials of low density. Interaction of uv radiation and plastics uv energy absorbed by plastics can excite photons, which then create free radicals.
Types of polymers classification of polymers characteristics of polymers properties of polymers streng slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. Plastic shapes include sheet, rod, hex, pipe, cubes, balls, and tubes. Classification of plastics materials sciencedirect. Bitumen, cellulose and shellac are the examples of this variety of plastics.
Types and properties pdf by mohammed shafi october 22, 2018 may 7, 2020 in this article, i will be explaining the different types of plastics used in our household applications as well as industrial applications in the form of thermoplastics and thermosetting plastics with there properties. Polymers have unique properties which can be tailored according to their intended purpose. At present, plastics find use in buildings mainly in thin coverings, panels, sheets, foams. Polycarbonate pc is the most common plastic in this category, isnt used as much in recent years due to it being associated with bisphenol a bpa. You may wish to replace the list of products and plastics with suitable examples from the classroom students are in. The properties of polyethylene were vital to the wartime development of. Feb 28, 2012 resins are any of the chemically modified natural resins or synthetic polymers which are physically similar, including thermoplastic materials such as polyvinyl, polystyrene, and polyethylene, as well as thermosetting materials such as polyesters, epoxies, and silicones. The other half of the main types of plastics is thermoplastic. Other books about the failure of various polymeric materials have been published since the. More than 50 families of plastics have been produced, and new types are currently. The difference between the two types of plastics can be remembered by memorizing the term thermosetting. Mechanicalpropertiesof polymers harvard university. Pet is the most widely produced plastic in the world. Plastics with sufficient surface hardness are having good durability.
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