Polymer.pdf

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POLYMERS

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olym rs are substances containing a large numberof structural units joined by the same type oflinkage.

These substances often form into a chain-likestructure. Polymers in the natural world have beenaround since the beginning of time. Starch,cellulose, and rubber all possess polymericproperties.

Man-made polymers have been studied since

1832. Today, the polymer industry has grown to belarger than the aluminum, copper and steelindustries combined.

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lymers are macromolecules (i.e. large long-chain molecules), based on repeating units, withfunctional and structural properties.

Ref: http://www.crcp.com.au/about-us/what-are-polymers



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Polymer materials have been steadily replacingtraditional materials in construction industry.

Construction applications of plastics include pipesand guttering, window and door profiles, glazing,

roofing, sealants and adhesives, cement,insulation, flooring and building panels.

Civil engineering applications includegeomembranes, road and sports surfaces, building

reinforcement and bridge building.

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Polymers already have a range of applicationsthat far exceeds that of any other class ofmaterial available to man.

Current applications extend from adhesives,coatings, foams, and packaging materials totextile and industrial fibers, composites,electronic devices, biomedical devices, opticaldevices, and precursors for many newlydeveloped high-tech ceramics.

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Substances whose molecules have high molarmasses and are composed of a large numberof repeating units. There are both naturally occurring and synthetic polymers.

Among naturally occurring polymers areproteins, starches, cellulose, and latex.Synthetic polymers are producedcommercially on a very large scale and have a

wide range of properties and uses. The materials commonly called plastics are all

synthetic polymers.

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Polymers are formed by chemical reactions inwhich a large number of molecules calledmonomers are joined sequentially, forming achain.

In many polymers, only one monomer isused. In others, two or three differentmonomers may be combined.

Polymers are classified by the characteristics

of the reactions by which they are formed.

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If all atoms in the monomers are incorporatedinto the polymer, the polymer is called anaddition polymer.

If some of the atoms of the monomers arereleased into small molecules, such as water,the polymer is called a condensation polymer.

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Polymers are substances whose molecules have high molar massesand are composed of a large number of repeating units. Polymers are formed by chemical reactions in which a large number

of molecules called monomers are joined sequentially, forming achain.

Polymers are bound by covalent forces and also by weak Van DerWaals forces and usually based on H, C and other non metallic

elements. They decompose at moderate temperatures (100-400 C), and are

lightweight Examples are plastics (nylon, Teflon, polyester), PVC and rubber Polymers offer many advantages over conventional materials

including lightness, resilience to corrosion and ease of processing

Examples of building components : ABS (Acrylonitrile Butadiene Styrene)- Drainage, Waste and Vent –

pipes PVC - usable for water, gas, drainage systems, gutters, house siding

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1. Polymers can be very resistant to chemicals. Most of our cleaning fluids in our house are packed in

plastics.

2. Polymers can be both thermal and electrical insulators.

Most of the appliances used in house eg; electrical outlets

and wiring are made of polymeric materials. Thermalresistance is evident in the kitchen with pot and pan handlessmade of polymers.

3. Polymers are very light in weight with varying degrees ofstrength.

Consider the range of applications, from toys to the frame

structure of space

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Acrylonitrile Butadiene Styrene pipe



Discussioncommon problems associate withpolymerized components in building.

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1. Chemical attack- chlorineattack

2. Heat resistance3. Appearance

4. Fracture5. Brittle

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