### <Success>Polymers (Lecture 4)</Success> <div style='float: left; width:100%;font-size:30px;text-align:left'> </div> <div style='float: right; width:0%;'> <p><img alt="image" src="/subject-images/iitpal/image/chemistry-class-12-unit-15-chapter-04-polymers-l-4_4-g5pvmdwzbua-012-0050.4.jpg"></p> </div>

### <Success>Synthesis of common polymers</Success> <div style='float: left; width:100%;font-size:30px;text-align:left'> <h4 id="1-polyethylene-polythene">(1) Polyethylene (Polythene)</h4> <p>n$CH_2=CH_2$ $\xrightarrow[\text { temp (350K-540K) radical initiator }]{\text { high pressure }}$ $(-CH_2-CH_2-)_n$ (branched)</p> <p>(i) HDPE/HDP</p> <p>n$CH_2=CH_2$ $\xrightarrow[\text { temp (333K-343K) 6-7 atom }]{\text { Z-N Catalyst }}$ $(-CH_2-CH_2-)_n$ (linear)</p> </div> <div style='float: right; width:0%;'> </div>

### <Success>Synthesis of common polymers</Success> <div style='float: left; width:100%;font-size:30px;text-align:left'> <h4 id="2-polytetrafluoroethylene-ptfe--teflon">2. Polytetrafluoroethylene (PTFE) / Teflon</h4> <p>n$CF_2=CF_2$ $\xrightarrow[\text { high Pressure }]{\text { Catalyst }}$ $(-CF_2-CF_2-)_n$</p> <h4 id="3-polyacrylonitrile-pan">3. Poly(acrylonitrile) (PAN)</h4> <p>n$CH_2=CH-CN^-$ $\xrightarrow[\text { Piramede catalyst }]{\text { Polymerization }}$ $(-CH_2-CH-CN^–)_n$</p> <p>commonly used as copolymer with styrene-SAN</p> </div> <div style='float: right; width:0%;'> </div>

### <Success>Synthesis of common polymers</Success> <div style='float: left; width:100%;font-size:30px;text-align:left'> <h4 id="4-polyamides--nylon">4. Polyamides / Nylon</h4> <p>(i) n $H_2N^{-}R^{’}-NH_2 $ +n $HOOC-R^{’}-COOH$ $\xrightarrow[\text { amidation }]{\text { direct }}$ $[-HN-R-NH-CO-R^{’}-CO-]_n$</p> <p>(ii) n$H_2N-R^{’’}-COOH$ $\xrightarrow[\text { Condensation }]{\text { self }}$ $[-HN-R^{’’}-CO-]_n$</p> <!--(iii) Lactam $\xrightarrow[\text {ring opening polymerisation}]{Catalyst}$ $\ (-CO-NH-)_n $--> <img src="https://imagedelivery.net/YfdZ0yYuJi8R0IouXWrMsA/82c148a2-dd55-4324-2457-c29121de3200/public" width="80%" > </div> <div style='float: right; width:0%;'> <p><img alt="image" src="/subject-images/iitpal/image/chemistry-class-12-unit-15-chapter-04-polymers-l-4_4-g5pvmdwzbua-3.jpg"></p> </div>

### <Success>Synthesis of common polymers</Success> <div style='float: left; width:100%;font-size:30px;text-align:left'> <h4 id="5-polyester">5. Polyester</h4> <p>(i) n$HO-R-OH+nHOOC-R^{’}-COOH$ $\xrightarrow[\text { Esterification }]{\text { direct }}$ $n[-O-R-O-CO-R^{’}-CO-]_n+(2n-1) H_2O$</p> <p>(ii) n$HO-R^{’’}-COOH$ $\xrightarrow[\text { Condensation }]{\text { Self }}$ $n[-O-R^{’’}-CO-]_n+(n-1)H_2O $</p> <img src="https://imagedelivery.net/YfdZ0yYuJi8R0IouXWrMsA/f374c792-3d06-4b09-d778-b2eb71c8d100/public" width="50%"> </div> <div style='float: right; width:0%;'> <p><img alt="image" src="/subject-images/iitpal/image/chemistry-class-12-unit-15-chapter-04-polymers-l-4_4-g5pvmdwzbua-4.jpg"></p> </div>

### <Success>Example</Success> <div style='float: left; width:100%;font-size:28px;text-align:left'> <!--$nHOOC-C_6H_6-COOH+nOH-CH_2CH_2-OH$ $\xLeftrightarrow[\text { high temp }]{\text { Catalyst }}$ $[-CO-C_6H_4-CO-O-CH_2-CH_2-O-]_n+(2n-1)H_2O$ --> <ul> <li>Poly (ethylene terephthalate)/(PET)/Dacron, Terylene, Mylar, etc.</li> <li>Proportion of PET fiber</li> <li>Good abrasion resistance</li> <li>Good chemical, hydrolysis, Vertical resistance</li> <li>Outstanding cream resistance - wrinkle-free clothes</li> <li>Trade names</li> </ul> <img src="https://imagedelivery.net/YfdZ0yYuJi8R0IouXWrMsA/f19b37e2-f246-426f-0d27-89389237fe00/public" width="80%" > </div> <div style='float: right; width:0%;'> <p><img alt="image" src="/subject-images/iitpal/image/chemistry-class-12-unit-15-chapter-04-polymers-l-4_4-g5pvmdwzbua-6.jpg"></p> </div>

### <Success>Trade names</Success> <div style='float: left; width:100%;font-size:30px;text-align:left'> <p>$Cl-CO-R-CO-Cl+R^{’}-OH-OH$ $\rightarrow$ $Polymer+HCL$</p> <p>$\ CH_3-O-CO-R^{’}-CO-O-CH_3$ + $\ HO-R^{’}-OH$</p> <p>$\Downarrow$</p> <p>Polyester + $CH_3OH$</p> </div> <div style='float: right; width:0%;'> <p><img alt="image" src="/subject-images/iitpal/image/chemistry-class-12-unit-15-chapter-04-polymers-l-4_4-g5pvmdwzbua-6.jpg"></p> </div>

### <Success>Synthesis of common polymers</Success> <div style='float: left; width:100%;font-size:28px;text-align:left'> <h4 id="6-phenol--formaldehyde-polymer">6. Phenol- formaldehyde polymer</h4> <p>(Bakelite and reaction polymer)/Phenolics</p> <p>pH, temp, ratio of Phenol and formaldehyde other reaction condition</p> <ul> <li>Novalac</li> <li>Bakelite</li> <li>Heated with formaldehyde</li> <li>Infusible</li> </ul> <img src="https://imagedelivery.net/YfdZ0yYuJi8R0IouXWrMsA/d725b24e-b0dc-40f0-bee5-b7ff4de2b300/public" width="70%" > </div> <div style='float: right; width:0%;'> <p><img alt="image" src="/subject-images/iitpal/image/chemistry-class-12-unit-15-chapter-04-polymers-l-4_4-g5pvmdwzbua-7.jpg"> <img alt="image" src="/subject-images/iitpal/image/chemistry-class-12-unit-15-chapter-04-polymers-l-4_4-g5pvmdwzbua-8.jpg"></p> </div>

### <Success>Hexamethylene tetramine </Success> <div style='float: left; width:100%;font-size:28px;text-align:left'> <p>$(CH_2)_6N_4$ $\leftarrow$ 6 moles of formaldehyde+4 moles of $NH_3$</p> <ul> <li>Methylene crosslinking</li> <li>Good resistance to impact, solvent, moisture</li> <li>High strength and dimensional properties</li> <li>Benzylamine crosslinking</li> <li>Electrical switches</li> <li>Combs</li> <li>Handle & various utensils</li> </ul> <img src="https://imagedelivery.net/YfdZ0yYuJi8R0IouXWrMsA/4e18a31a-94f8-4d3c-aaee-eb145f599400/public" width="40%" > </div> <div style='float: right; width:0%;'> <p><img alt="image" src="/subject-images/iitpal/image/chemistry-class-12-unit-15-chapter-04-polymers-l-4_4-g5pvmdwzbua-9.jpg"></p> </div>

### <Success>Synthesis of common polymers</Success> <div style='float: left; width:90%;font-size:30px;text-align:left'> <h4 id="7-amino-plastics--polymers">7. Amino plastics / polymers</h4> <p>Formaldehyde+urea $\rightarrow$</p> <p>$+$ melamine $\rightarrow$</p> <ul> <li>Reaction is controlled by pH and temprature</li> <li>Heating in pressure of added acid catalyst</li> <li>prepolymer intermediate pdt</li> </ul> <img src="https://imagedelivery.net/YfdZ0yYuJi8R0IouXWrMsA/6f36ef05-5cb5-4ee3-0219-4797ee375700/public" width="50%" > </div> <div style='float: right; width:00%;'> <p><img alt="image" src="/subject-images/iitpal/image/chemistry-class-12-unit-15-chapter-04-polymers-l-4_4-g5pvmdwzbua-10.jpg"></p> </div>

### <Success>Some other commercial important polymers</Success> <div style='float: left; width:90%;font-size:30px;text-align:left'> <img src="https://imagedelivery.net/YfdZ0yYuJi8R0IouXWrMsA/73188dda-4714-49ad-fcc6-7dcb6bea8a00/public" width="70%" > </div> <div style='float: right; width:0%;'> <p><img alt="image" src="/subject-images/iitpal/image/chemistry-class-12-unit-15-chapter-04-polymers-l-4_4-g5pvmdwzbua-11.jpg"></p> </div>

### <Success>Rubber</Success> <div style='float: left; width:100%;font-size:30px;text-align:left'> <ul> <li>Vulcalization of rubber using sulphur by</li> </ul> <p>Charles Goodyear in 1839 in USA Patent was granted 1844</p> <ul> <li>Elastic properties were improved</li> <li>Tackines were eliminated</li> <li>Thomas Hancock in London 1843 patent granted</li> <li>1851 Nelson Goodyear</li> </ul> </div> <div style='float: right; width:0%;'> <p><img alt="image" src="/subject-images/iitpal/image/chemistry-class-12-unit-15-chapter-04-polymers-l-4_4-g5pvmdwzbua-12.jpg"></p> </div>

### <Success>Natural rubber (NR)</Success> <div style='float: left; width:99%;font-size:30px;text-align:left'> <p>Milky-white latex which contain colloidal dispersion of rubber hydrocarbons.</p> <img src="https://imagedelivery.net/YfdZ0yYuJi8R0IouXWrMsA/147c9370-ad0e-465c-ebe7-b1f0738a6000/public" width="80%" > <ul> <li>Poly (monomer)</li> <li>Poly(ethylene)</li> <li>Poly(vinylchloride)</li> <li>Poly (isoprene)</li> <li>Cis-1,4-Poly(2-methyl-1,3-butadiene)</li> </ul> </div> <div style='float: right; width:01%;'> <p><img alt="image" src="/subject-images/iitpal/image/chemistry-class-12-unit-15-chapter-04-polymers-l-4_4-g5pvmdwzbua-13.jpg"></p> </div>

### <Success>Vulcanisation of rubber</Success> <div style='float: left; width:100%;font-size:30px;text-align:left'> <ul> <li>NR become soft > 335K</li> <li>Hard, brittle < 283 K</li> <li>Soluble in non-polar solvents and non-resistant to attack to oxidizing agents</li> </ul> </div> <div style='float: right; width:0%;'> <p><img alt="image" src="/subject-images/iitpal/image/chemistry-class-12-unit-15-chapter-04-polymers-l-4_4-g5pvmdwzbua-14.jpg"></p> </div>

### <Success>Vulcanisation</Success> <div style='float: left; width:100%;font-size:30px;text-align:left'> <ul> <li>Raw rubber + sulphur + an appropriate additive $\xrightarrow{373K-415K ( \text long \hspace{1mm} hours) }$</li> </ul> <img src="https://imagedelivery.net/YfdZ0yYuJi8R0IouXWrMsA/9bc8c41e-31b7-4410-b69f-096cf70ebd00/public" width="80%" > <ul> <li>5% Sulphur -for tyre rubber</li> </ul> </div> <div style='float: right; width:0%;'> <p><img alt="image" src="/subject-images/iitpal/image/chemistry-class-12-unit-15-chapter-04-polymers-l-4_4-g5pvmdwzbua-15.jpg"></p> </div>

### <Success>Synthetic rubbers</Success> <div style='float: left; width:100%;font-size:30px;text-align:left'> <ul> <li>Any vulcanizable rubber like polymer which is capable of getting stretch >2 times - reversible</li> <li>Homo or copolymers 1,3-butadiene and its derivatives</li> </ul> <ol> <li> <p>SBR (Styrene-butadiene rubber)- Buna-S</p> </li> <li> <p>CR (Polychloroprene rubber)</p> </li> </ol> <!--n n$CH_2=CH-CH=CH_2$ (Chloroprene) $\rightarrow$ $[-CH_2-CH-CH-CH_2]_n$ (Neoprene)--> <img src="https://imagedelivery.net/YfdZ0yYuJi8R0IouXWrMsA/f9e376db-b1f9-4fc4-dca0-690d70578f00/public" width="90%" > <p>Gloves gasket uses</p> </div> <div style='float: right; width:0%;'> <p><img alt="image" src="/subject-images/iitpal/image/chemistry-class-12-unit-15-chapter-04-polymers-l-4_4-g5pvmdwzbua-16.jpg"></p> </div>

### <Success>Nitrile rubber (NBR)</Success> <div style='float: left; width:100%;font-size:30px;text-align:left'> <p>Copolymer of 1,3-butadiene + acrylo acrylonitrile</p> <!--n$CH_2=CH-CH=CH_2+nCH_2=CH-CN^-$ $\rightarrow$ $[-CH_2-CH=CH-CH_2-CH_2-CH-CN^--]$ Buna-$N^-$--> <ul> <li>Resistant</li> <li>Petrol</li> <li>Lubricating oil</li> <li>Organic solvents - making oil seeds , tank lining etc</li> </ul> <img src="https://imagedelivery.net/YfdZ0yYuJi8R0IouXWrMsA/62190731-c7d1-4b6f-3ef3-9bd83b138200/public" width="70%" > </div> <div style='float: right; width:0%;'> <p><img alt="image" src="/subject-images/iitpal/image/chemistry-class-12-unit-15-chapter-04-polymers-l-4_4-g5pvmdwzbua-17.jpg"></p> </div>

### <Success>Biodegradable polymers</Success> <div style='float: left; width:100%;font-size:30px;text-align:left'> <p>Capable of undergoing decomposition into $CO_2$, $CH_4$, $H_2O$, inorganic compounds, biomass predominantly done by enzymatic action of microorganisms like bacteria</p> <ul> <li> <p>Natural Polymers</p> </li> <li> <p>Cellulose</p> </li> <li> <p>Chitin</p> </li> <li> <p>Starch</p> </li> <li> <p>Polypeptides</p> </li> </ul> </div> <div style='float: right; width:0%;'> <p><img alt="image" src="/subject-images/iitpal/image/chemistry-class-12-unit-15-chapter-04-polymers-l-4_4-g5pvmdwzbua-18.jpg"></p> </div>

### <Success>Aliphatic polyesters</Success> <div style='float: left; width:100%;font-size:30px;text-align:left'> <ul> <li>poly (Hydroxy alkanoates) (PHA)</li> <li>Poly ($\beta$ -hydroxybutarate -co-$\beta$-hydroxy Valerate) PHBV</li> </ul> <!--$OH-CH(CH_3)-CH_2-COOH$ (3-hydroxybutanoic acid)+3-hydroxy valeric acid $\rightarrow$ PHBV polylactide Poly (lactides - co-glycolides) Polycaprolactones--> <img src="https://imagedelivery.net/YfdZ0yYuJi8R0IouXWrMsA/27136071-cadd-48d6-0b00-16043de34300/public" width="90%" > </div> <div style='float: right; width:0%;'> <p><img alt="image" src="/subject-images/iitpal/image/chemistry-class-12-unit-15-chapter-04-polymers-l-4_4-g5pvmdwzbua-19.jpg"></p> </div>

### <Success>Question</Success> <div style='float: left; width:100%;font-size:30px;text-align:left'> <h4 id="nylon-2---nylon-6"><strong>Nylon 2 - Nylon-6</strong></h4> <p><strong>Q.</strong> What are polymers ?</p> <p><strong>Q.</strong> Why should you study ?</p> <p><strong>Q.</strong> What are different types polymers ?</p> <p><strong>Q.</strong> How these polymers are prepared ?</p> <p><strong>Q.</strong> Some common examples of polymers and their applications ?</p> <p>Biodegradable polymers</p> </div> <div style='float: right; width:0%;'> <p><img alt="image" src="/subject-images/iitpal/image/chemistry-class-12-unit-15-chapter-04-polymers-l-4_4-g5pvmdwzbua-20.jpg"> <img alt="image" src="/subject-images/iitpal/image/chemistry-class-12-unit-15-chapter-04-polymers-l-4_4-g5pvmdwzbua-21.jpg"></p> </div>

## <Success>Thank You</Success> <div style='float: left; width:100%;font-size:30px;text-align:left'> </div> <div style='float: right; width:0%;'> <!----> </div>