I take this chance to show my ballots of thanks to all those guidelines who truly acted as buoy uping pillars to edify our manner throughout this undertaking that has led to successful and satisfactory completion of this survey. We are truly thankful to our HOD for supplying us with an chance to set about this undertaking in this university and supplying us with all the installations. We are extremely grateful to Mr. Harminder Singh for his active support, valuable clip and advice, whole-hearted counsel, sincere cooperation and pains-taking engagement during the survey and in finishing the assignment of fixing the said undertaking within the clip stipulated.
Last, We are grateful to all those, peculiarly the assorted friends who have been instrumental in making proper, healthy and conductive environment and including new and fresh advanced thoughts for us during the undertaking, their aid, it would hold been highly hard for us to fix the undertaking in a clip edge model
Polymers were discovered long before anyone understood what they were. It was n’t until 1920 that German chemist Hermann Staudinger ( 1881-1965 ) made his macromolecular hypothesis, proposing that polymers are really elephantine molecules formed by the lasting fond regard of infinite smaller molecules.
A polymer is a big “ MOLECULE ” composed of reiterating structural typically connected by chemical bonds like covalent bonds. Polymers are composed of really high molecular multitudes formed by the combination of big figure of simple molecules.
Polymers ( or supermolecules ) are really big molecules made up of smaller units called monomers or reiterating units, covalently bonded together.
- Monomers / Repeat Unit of measurements
- Microstructure: –
The individuality of the monomer residues ( reiterate units ) consisting a polymer is its first and most of import property.
The microstructure of a polymer ( sometimes called constellation ) relates to the physical agreement of monomer ( which I have explained above ) residues along the anchor of the concatenation.
Categorization OF Polymers: –
On the footing of structure-
- LINEAR Polymers
- BRANCHED Polymers
- CROSS-LINKED Polymers
On the footing of molecular forces
- Thermosetting polymers
These are the polymers which can be easy softened repeatedly when heated and hardened when cooled with small alteration in their belongingss. When heated due to the absence of cross links, they become free to travel and and can be moulded into any coveted forms.
- EXAMPLES- Polyvinyl Chloride ( PVC ) and Polystyrene and Polymethyl methacrylate
These are the polymers which undergo lasting alteration on warming and can non be remoulded into our coveted form. On heating their cross links get extremely linked with each other and becomes difficult and infusible.
- EXAMPLES-Bakelite, formaldehyde etc.
- Tensile strength
- Melting point
- Boiling point
Higher tensile strength holds a greater weight before snarling. Tensile strength additions with polymer concatenation length and crosslinking of polymer ironss.
The term runing point when applied to polymers, suggests non a solid-liquid stage passage but a passage from a crystalline or semi-crystalline stage to a solid formless stage.
The boiling point of a polymeric stuff is strongly dependent on concatenation length. The polymers with a big grade of polymerisation do non exhibit a boiling point because they are decomposed before making their several theoretical boiling point.
FUN FACT: – The polymer inside disposable nappies is called Na polyacrylate. It can immediately absorb about 800 times its mass in H2O.
APPLICATIONS OF POLYMERS: –
Molecular scientific discipline has developed tremendously in recent epochs. Molecular scientific discipline has a major function in our lives. It has become a necessity in our day-to-day modus operandis we shall speak now about the basic applications of polymers without which life was n’t that easy. We are traveling to discourse some of the chief polymers used in our lives.
History OF Rubber: – Natural gum elastic, obtained from the sap of the Hevea tree. Rubber was named by the chemist Joseph Priestley who found that a piece of coagulated latex gum was good for rubbing out pencil Markss on paper.
TWO TYPES OF RUBBER ARE THERE: –
- NATURAL RUBBER
- VULCANIZED RUBBER ( SYNTHETIC RUBBER )
Natural RUBBER: –
Natural gum elastic is a polymer of isoprene ( 2-methyl-1, 3-butadiene ) , with a united web structure.There is no cross links between the polymer ironss. It is non difficult and tough. It becomes gluey and soft when heated. It can be easy deformed but regains its original form after the emphasis is released. It involves a add-on reaction in which one dual bond in isoprene unfastened to organize a new bond with following unit organizing a big concatenation.
Cured Rubber: – .
A chemical reaction of S ( or other vulcanising agent ) with gum elastic or plastic to do cross-linking of the polymer ironss ; it increases strength and resilience of the polymer chemically ; the procedure involves the formation of cross-linkages between the polymer ironss of the gum elastic ‘s molecules. It was invented by Charles Goodyear in 1839.The formation of cross links formed at the clip of vulcanisation at the reactive sites makes rubber difficult, tough with greater tensile strength. It has really high snap, opposition to oxidization and organic dissolvers. The sulfur span in this figure prevents the faux pas of the ironss and rubber can be stretched to a limited extent and when tenseness is removed the ironss try to gyrate up recover its original form.
OTHER TYPES OF RUBBER: –
- NEOPRENE RUBBER: –
- SBR ( Styrene Butadiene Rubber ) : -Known as BUNA-S
- NITRILE Rubber: – Recognized as BUNA-N
Use: – used as dielectric, doing conveyer belts, pressman roller belts are besides made from it.
Use: – it is used for doing automobile Surs and footwears.
Use: -it is used for doing oil seals, industry of hosieries and armored combat vehicle linkings.
REACTIONS INVOLVING IN THERE FORMATIONS: –
- Plastics OR POLYHALO-OLEFINS: –
- POLYVINYLCHLORIDE- ( PVC ) : –
A really utile but common trade good of our life. But nowadays it has become a serious job due to its job of debasement which is a procedure which is a clip devouring procedure. These are called polyhalo-olefins because they are derived from halogen substituted alkenes.
Its monomer is unit is vinyl chloride. it is prepared by heating vinyl chloride in an inert dissolver in the presence of peroxides ( eg.dibenzoyl peroxides ) .It isa difficult horny stuff. It is a thermoplastic polymer and its malleability can be increased. Fig 15.0
- It is used in fabrication of rain coats, manus bags, drape apparels, playthings
- Artificial flooring.
- As a good insulating stuff in wires and other electrical goods.
- For doing gramophone records.
Tough stuff resistant to heat and chemical actions such as acids and bases. It is an add-on polymer of tetraflouroethylene.It is bad music director of heat.
- It is used as a stuff resistant to heat and chemical onslaught in family plants.
- For surfacing articles and cooking utensil to do them non-sticky as non stick utensils
- For doing gaskets, pump packaging, valve, seals, non-lubricated bearings, etc.
Fibers represent a really of import application of polymeric stuffs, including many illustrations from the classs of plastics and elastomers.It involves ester linkages
TYPES OF POLYESTERS ( FIBRES ) : –
- TERYLINE: -It is a polymer of ethene ethanediol and terephthalic acid. Besides known as Dacron.
- For doing cloth by blending with cotton.
- For doing magnetic recording tapes.
- Used for doing bristles of coppices.
- In fabrics and besides for doing sheets. It is blended with wool to do socks and jumpers.
It is used in the industry of Sur, cords, cloths, and ropes.
We have tried to give a brief information on polymers.Polymers are everyplace around us and we tried to demo a glance of polymers applications which are normally used in our lives like plastics nylon and twenty-four hours to twenty-four hours used trade goods.
MATERIAL AND FIGURE REFRENCES: –
- hypertext transfer protocol: //www.plastiquarian.com/top.htm
- hypertext transfer protocol: //www.csua.berkely.edu/~ranga/school/me223/nylon.gif
- hypertext transfer protocol: //www.openlearn.open.ac.uk/course/view.php? id=2937
- hypertext transfer protocol: //www.britanica.com/EBchecked/topic/468696/polymer
- hypertext transfer protocol: //www.polymertalk.com/history_of_polymers.php
- hypertext transfer protocol: //en.wikipedia.org/wiki/silicone
- hypertext transfer protocol: //en.wikipedia.org/wiki/branching_ % 28chemistry % 29
- hypertext transfer protocol: //www.polymertalk.com/classification_of_polymers.php
- hypertext transfer protocol: //docs.google.com/viewer? a=v & A ; q=cache: Wbn5XOJDt: www.cmse.ed.ac.uk/MSE3/Topics/MSE3-polymers.pdf+intoduction+of+polymers & A ; hl=en & A ; gl=in & A ; sig=AHIEtbQ22RNSIoIyoXUP9HtDd-nakz-w
- hypertext transfer protocol: //www.cem.msu.edu/~reusch/VirtualText/polymers.htm