312895024-investigatory-project-on-polymers-for-class-12-students-in-CBSE.pdf

Certifcate  This is to certiy that Mr. Mr. yash Patel Student o Xll science Roll Roll no__________ Worked on project titled-Polyer titled-Polyer held in !ha"#ati international pu$lic school durin" the acadeic year %&'(-%&'). *e #orked sincerely sincerely under un der the "uidance o aculties and prepar prepared ed this dissertation.

+,ternal +,ternal Teacher each er  Teacher  Teacher

Su$ject Su$ject

Principal

ackno#led"eent irst o all / a iensely inde$ted to ali"hty "od or his $lessin" and "race #ithout #hich / could not ha0e $een a success. / hu$ly consider a pri0ile"e and honor to e,press y heartiest and proound "ratitude to Mr. Rajendra.S.Mal#al principal !/PS Patan. or his appropriate direction 0alua$le su""estion under jud"in" assistance so "enerously e,tended to e. / #ish to e,press y deepest eelin"s o "ratitude to Mr. 1a$akishor sorokhai$a cheistry departent !/PS Patan. or his erudite in0ol0eent and sustained "uidance #hich has $een pi0otal in y project #ork. *is inute o$ser0ation precious insi"hts critical coents ha0e indeed "reatly helped to shape y ideas.  This "uidance and support recei0ed or y entire classates #ho contri$uted and #ho are contri$utin" to this project is 0ital or the success o this project. / a "rateul or their constant support and help. / also o#e sense o "ratitude to y parents or encoura"eent and support throu"hout the project.

- 2ash Patel

C31T+1TS 1. Polymer 2. Polymer science 3. Historical development 4. Laboratory synthesis 5. Mechanical properties

Introduction

While the term polymer in popular usae suests !plastic!" polymers comprise a lare class o# natural and synthetic materials $ith a variety o# properties and purposes. %atural polymer materials such as shellac and amber have been in use #or centuries. Paper is manu#actured #rom cellulose" a naturally occurrin polysaccharide #ound in plants. &iopolymers such as proteins and nucleic acids play important roles in bioloical processes. Henri &raconnot's pioneerin $or( in derivative cellulose compounds is perhaps the earliest important $or( in modern polymer science. )he development o# vulcani*ation later in the nineteenth century improved the durability o# the natural polymer rubber" sini#yin the +rst populari*ed semi,synthetic polymer. )he +rst $holly synthetic polymer" &a(elite" $as discovered in 1-/. 0ntil the 1-2s" most scientists believed that polymers $ere clusters o# small molecules called colloids" $ithout de+nite molecular $eihts" held toether by an un(no$n #orce" a concept (no$n as association theory. In 1-22" erman chemist Hermann taudiner proposed that polymers $ere comprised o# !macromolecule s! consisted o# lon chains o# atoms held toether by covalent bonds. )houh poorly received at +rst" eperimental $or( by Wallace 6arothers"Herman Mar( " and others provided #urther evidence #or taudiner's theory. &y the mid,1-3s" the macromolecular theory o# polymer structure $as $idely accepted. 7or this and other $or( in the +eld" taudiner $as ultimately a$arded the %obel Pri*e. In the intervenin century" synthetic polymer materials such as %ylon" polyethylene" )e8on" andsilicone have #ormed the basis #or a bureonin polymer industry. ynthetic polymers today +nd application in nearly every industry and area o# li#e. Polymers are used in the #abrication o# microprocessors"

 Polymer 4ppearance o real linear polyer chains as recorded usin" an atoic orce icroscope on surace under li5uid ediu. Chain contour len"th or this polyer is 6%&7 n8 thickness is 6&.7 n. 4 polymer is a lar"e olecule 9acroolecule: coposed o  repeatin" structural units. These su$units are typically connected $y co0alentcheical $onds. 4lthou"h the ter  polymer  is soeties taken to reer to plastics it actually encopasses a lar"e class o  natural and synthetic aterials #ith a #ide 0ariety o properties. !ecause o the e,traordinary ran"e o properties o polyeric aterials they play an essential and u$i5uitous role in e0eryday lie.  This role ran"es ro ailiar synthetic plastics and elastoers to natural $iopolyers such as nucleic acids  and proteins that are essential or lie. 1atural polyeric aterials such as shellac a$er and natural ru$$er ha0e $een used or centuries. 4 0ariety o other natural polyers e,ist such as cellulose #hich is the ain constituent o #ood and paper.  The list o synthetic polyers  includes synthetic ru$$er !akelite neoprene nylon P;C polystyrene polyethylene polypropylene polyacrylonitrile P;! silicone and any ore. Most coonly the continuously linked $ack$one o a polyer used or the preparation o plastics consists ainly o car$on atos. 4 siple e,aple is polyethylene #hose repeatin" unit is $ased on ethyleneonoer. *o#e0er other structures do e,ist8 or e,aple eleents such as silicon or ailiar aterials such as silicones

Polymer science Most polyer research ay $e cate"ori polyer cheistry  9or acroolecular cheistry: and polyer physics. /n practice the distinction $et#een the t#o is rarely clearcut.  The study o $iolo"ical polyers their structure unction and ethod o synthesis is "enerally the pur0ie# o $iolo"y $iocheistry and $iophysics. These disciplines share soe o the terinolo"y ailiar to polyer science especially #hen descri$in" the synthesis o $iopolyers such as ?14 or polysaccharides. *o#e0er usa"e di@erences persist such as the practice o usin" the ter acroolecule to descri$e lar"e non-polyer olecules and cople,es o ultiple olecular coponents such as heo"lo$in. Su$stances #ith distinct $iolo"ical unction are rarely descri$ed in the terinolo"y o polyer science. or e,aple a protein is rarely reerred to as a copolyer

Historical development Startin" in 'A'' *enri !raconnot did pioneerin" #ork in deri0ati0e cellulose copounds perhaps the earliest iportant #ork in polyer science. The de0elopent o 0ulcani