Polymers and Plastics

Timeline - Precursors 1839 - Natural Rubber - method of processing invented by Charles Goodyear Timeline - Beginning of the Plastic Era with Semi Synthetics 1839 - Polystyrene (PS) discovered - Eduard Simon 1862 - Parkesine - Alexander Parkes 1863 - Cellulose Nitrate or Celluloid - John Wesley Hyatt 1872 - PVC - first created by Eugen Baumann 1894 - Viscose Rayon - Charles Frederick Cross, Edward John Bevan Timeline - Thermosetting Plastics and Thermoplastics 1908 - Cellophane ® - Jacques E. Brandenberger 1909 - First true plastic Phenol-Formaldehyde tradenamed Bakelite -Leo Hendrik Baekeland 1926 - PVC - Walter Semon invented a plasticized PVC. 1927 - Cellulose Acetate 1933 - Polyvinylidene chloride or Saran also called PVDC - accidentally discovered by Ralph Wiley, a Dow Chemical lab worker. 1935 - LDPE - Reginald Gibson and Eric Fawcett 1936 - Acrylic or Polymethyl Methacrylate 1937 - Polyurethanes for plastics materials and Perlon for fibers. - Otto Bayer and co-workers discovered and patented the chemistry of polyurethanes 1938 – Polystyrene(PS) made practical 1938 - Polytetrafluoroethylene or PTFE tradenamed Teflon - Roy Plunkett 1939 - Nylon and Neoprene -Wallace Hume Carothers 1941 - Polyethylene Terephthalate or PET - Whinfield and Dickson 1942 - LDPE 1942 - Unsaturated Polyester also called PET patented by John Rex Whinfield and James Tennant Dickson 1951 - HDPE - Paul Hogan and Robert Banks 1951 - PP - Paul Hogan and Robert Banks 1953 - Saran Wrap introduced by Dow Chemicals. 1954 - Styrofoam a polystyrene foam was invented by Ray McIntire for Dow Chemicals 1964 - Polyimide 1970 - Thermoplastic Polyester (includes Dacron, Mylar, Melinex, Teijin, and Tetoron) 1978 - Linear Low Density Polyethylene 1985 - Liquid Crystal Polymers

Nylon stocking Nylon 은 DuPont 사 Wallace Carothers 에 의해 발명(1938) 1940년 5월 15일 미국 뉴욕시에서 나일론으로 만든 4백만 켤레의 스타킹은 판매시작 수 시간만에 매진 이차대전 때 군사용품으로 전환되어 민간수요는 1945년 이후에 보급 X200 SEM/EDX image Dee Breger ,Mgr. SEM/EDX Facility, Lamont-Doherty Earth Observatory

History of Polymers 1870년 미국 John Hyatt 셀루로이드(nitrocellulose + camphor) 개발 영국의 Alexander Parkes가 최초 개발한 Parksine을 응용 상아 대체 - 당구공 제조회사의 만 달러 공모 1907년 Leo Baekeland가 Bakelite(페놀-포름알데히드수지)개발, 대량 생산 1938년 Dow사는 폴리스티렌 대량생산 1939년 듀퐁사는 나일론(nylon-6,6)을 대량생산하여 스타킹 판매 시작. 고분자 화학 발달에 계기

History of Polymers 1839년 Charles Goodyear 가 천연고무(latex) 에 황을 가하여 타이어용의 고무 대량생산 고무의 내열 특성 때문에 타이어에 적합

Wallace Carothers, inventor of Nylon (1930 at DuPont). (1896 - 1937) 6

Hermann Staudinger(1953 Nobel Prize for chemistry) In a landmark paper published in 1920, Staudinger concluded the structure of rubber and other polymeric substances: “polymers were long chains of short repeating molecular units linked by covalent bonds.” Staudinger termed makromoleküls paved the way for the birth of the field of polymer chemistry.

A.J.Heeger A.G. MacDiarmid H.Shirakawa Nobel laureates in polymer science K. Ziegler G. Natta (1897-1973) (1903-1979) P.J.Flory (1936- ) 화학 H. Staudinger (1881-1965) 1953 1963 1974 A.J.Heeger A.G. MacDiarmid H.Shirakawa (1910-1985) (1927- ) (1936- ) P.-G de Gennes (1932- ) 물리 2000 1991

polymer = poly(많은)+meros (부분) 동일한 구조( 단위체, monomer )의 반복단위로 된 화합물 중합체라고도 불린다.

Tacticity Tacticity – stereoregularity of chain isotactic – all R groups on same side of chain syndiotactic – R groups alternate sides atactic – R groups random 10

cis/trans Isomerism cis trans cis-isoprene (natural rubber) bulky groups on same side of chain trans trans-isoprene (gutta percha) bulky groups on opposite sides of chain 11

Homopolymer is a polymer made up of only one type of monomer ( CF2 CF2 )n Teflon ( CH2 CH2 )n Polyethylene ( CH2 CH )n Cl PVC Copolymer is a polymer made up of two or more monomers ( CH CH2 CH2 CH CH CH2 )n Styrene-butadiene rubber

Copolymers two or more monomers polymerized together random random – A and B randomly vary in chain alternating – A and B alternate in polymer chain block – large blocks of A alternate with large blocks of B graft – chains of B grafted on to A backbone A – B – random alternating block graft 13

Thermoplastics vs. Thermosets Callister, Fig. 16.9 T Molecular weight Tg Tm mobile liquid viscous rubber tough plastic partially crystalline solid • Thermoplastics: -- little crosslinking -- ductile -- soften w/heating -- polyethylene polypropylene polycarbonate polystyrene • Thermosets: -- large crosslinking (10 to 50% of mers) -- hard and brittle -- do NOT soften w/heating -- vulcanized rubber, epoxies, polyester resin, phenolic resin Adapted from Fig. 15.19, Callister 7e. (Fig. 15.19 is from F.W. Billmeyer, Jr., Textbook of Polymer Science, 3rd ed., John Wiley and Sons, Inc., 1984.) 14

Annual U.S. production of plastics from 1935 to 1997

Comparison with Other Industries United States Plastics industry is the nation’s 4th largest manufacturing industry (shipments): Motor Vehicles and Equipment Petroleum Refining Electronic Components and Accessories Plastics (Source: Probe Economics, Inc. 2004)

<Source : Plastics Age Dec. 2005> 주요국 별 범용 플라스틱 생산 · 소비 현황 <2003 : 1,000 MT> 국별 생산 수출 수입 국내소비 1인당 소비량 (kg) 미국 독일 일본 프랑스 벨기에 타이완 카나다 인도 브라질 스페인 이태리 영국 48,513 16,800 13,978 6,725 6,700 6,639 5,001 4,675 4,141 3,841 3,705 2,774 - 10,500 4,712 4,935 11,050 3,730 3,983 757 901 2,305 1,340 1,745 6,310 1,249 3,940 6,041 636 3,000 475 577 2,980 4,830 3,627 51,469 12,610 10,515 5,760 1,800 3,444 4,018 4,186 3,817 4,517 6,930 4,656 177 153 82 92 183 128 (2002) 126 4 22 108 123 89 합계 155,216 <Source : Plastics Age Dec. 2005> 17 17

<자료 : 한국석유화학공업협회, 광공업통계조사보고서 (통계청). > 국내 범용 합성수지 수급 현황 <단위 : 1,000 톤> 수출 수입 LDPE HDPE PP PS ABS PVC 822 1,204 1,616 712 975 499 41 12 14 19 5 51 803 1,139 1,653 636 1,082 518 42 15 34 6 48 열가소성 수지 5,828 142 5,831 157 Phenolic Melamine UPE Epoxy PU 10 1 74 24 26 9 3 32 2 17 93 28 27 36 16 열경화성 수지 124 89 152 92 합계 5,952 231 5,983 249 PETE is not shown because PETE is from EG(ethylene glycol) + TPA(terephtalic acid) <자료 : 한국석유화학공업협회, 광공업통계조사보고서 (통계청). > 18

주요국 별 1인당 플라스틱 소비량 kg per capita 107 82 90 128 177 126 153 92 123 79 183 <자료 : Plastics Age Dec. 2005, 광공업 통계조사보고서 (통계청)> ☞ Korea still has potentials of Sustainable Growth in Polymer Industry

Out of Crude Oil

42 gallon 21

Polymers Scientists use one or more of the following strategies to design the molecular feature of the polymer chain: 1. length of the chain (# of monomer units); 2. 3-D arrangement of the chains in the solid; 3. branching of the chain: 4. chemical composition of the monomer units; 5. bonding between the chains; 6. orientation of the monomer units within the chain.

Polymers Polyethylene: most common plastic from the monomer ethylene (C2H4) polyethylene ethylene

A. 부가중합 (Addition polymerization) A1. Radical Polymerization • Initiation: homolytic cleavage of e.g. a peroxide. • Termination of the polymerization by reaction of two radicals:

A2. Cation Polymerization • Initiators: (Lewis) acids such as H+ and BF3.

A3. Anion Polymerization • Initiators: anions such as in C4H9Li or NaOC2H5.

SOME VINYL POLYMERS

RUBBERS: POLYMERS FROM DIENES

POLYMERIZATION PROCESS • Resonance stabilization of allylic radical. • Synthetic rubbers: mixture of structural fragments. • Natural rubbers (latex): regular structure with only Z-double bonds.

B. 축합중합 (Condensation polymerization) Polyesters polyethylene terephthalate PET, dacron Polycarbonates Lexan(GE)

Polyamides (nylons) Cf) Amide from lactam • Use in fibers, strong threads and clothes.

* 중부가 (Poly addition) : No low molecular by-product • Actually not a polycondensation, but a step-growth polymerization • Application as insulation material (PUR foam).

C. 부가중합 (Addition condensation)

개환중합 (Ring-opening polymerization)

Big Six Polymers Polyethylene (LDPE, HDPE) Polypropylene (PP) Polystyrene (PS) Polyvinyl chloride (PVC) Polyethyle terephthalate (PETE) -thermoplastic, meaning they can be melted and reshaped. They also tend to be flexible. -PE and PP have both crystalline and amorphous regions. The others - PS, PVC, and PET - are not crystalline. Their chains are bonded randomly.

36

Uses of the “Big Six” polymers 37

A growing PET polymer chain terephthalic acid ethylene glycol

Polyethylene(PE) Radical polymerization of ethylene 39

Classification of PE Polyethylenes은 밀도에 따라 분류한다. 고분자의 가지치기 종류,갯수에 따라 밀도가 변한다. HDPE (high density PE) - 우유통 MDPE (medium density PE) - 배관 LDPE (low density PE) - 플라스틱백, squeeze LLDPE (linear low density PE) a substantially linear polymer, with significant numbers of short branches, commonly made by copolymerization of ethylene with longer-chain olefins.

LDPE vs. HDPE - branching a HDPE molecule an LDPE molecule

Uses of LDPE 유연성 강도와 내화학성이 우수 발포제품 우수한 전기절연성, 유연성 마요네즈나 케찹 용기 등의 플라스틱 squeeze bottle 강도와 내화학성이 우수 약품, 음료, 화장품 용기에도 많이 사용된다 발포제품 기포를 함유하고 있으므로 완충포장재, 고층건물의 지붕바닥재 및 소음 방지재, 스포츠레저용품 우수한 전기절연성, 유연성 옥내 외 각종 전선의 절연체, 피복

LDPE

Properties of LDPE HDPE보다 가지가 많다 분자간 힘이 약하게 작용 the chains do not "fit well" together. mp 105 ~ 115 °C 분자간 힘이 약하게 작용 as the instantaneous-dipole induced-dipole attraction is less. a lower density and tensile strength, increased malleability and faster biodegradation created by free radical polymerization

FT-IR of LDPE & HDPE

HDPE Branching이 거의 없는 고분자 사슬 제조방법 stronger intermolecular forces mp 120 ~ 130 °C 제조방법 by an appropriate choice of catalysts (e.g. Ziegler catalysts, 노벨화학상, 1963) reaction conditions.

Properties of HDPE 전기적 성질 광학적 성질 내약품성 HDPE는 전형적인 극성 고분자로서 전기장(electric field)속에서 이온 분극이나 쌍극자 분극이 없고 전자분극이나 원자분극만 존재한다. 뛰어난 절연성 때문에 HDPE는 전선(wire) & 케이블(cable)용 절연 소재로 널리 사용되고 있다. 광학적 성질 HDPE의 광학적 성질은 불투명도(haze), 광택성(gloss), 투명도(transparency) 등으로 특성화되며 이러한 성질들은 내부결정상태, 가공조건 등에 의해 좌우된다. HDPE 필름의 표면이 평활하지 못하면 불투명도(haze)가 증가하고, 내부에 공간(void)이 많거나 결정도가 크면 결정들(spherulites) 사이 경계면에서의 빛의 분산, 굴절로 인해 투명성이 저하되는데, 이는 일반적으로 HDPE가 LDPE보다 불투명한 이유이다. 내약품성 HDPE는 구조적으로 결정도가 높고 3차 수소(tertiary H)의 수가 매우 적기 때문에 다른 polyolefin에 비해 산화에 대한 안정성이 뛰어나다. 또한 응력이 가해지지 않은 상태에서 60℃까지는 보통의 유기용제나 산, 알칼리 등에 대하여 극히 안정하므로 각종 화학약품의 용기로 사용될 수 있다. Xylene 용액 속에서는 온도가 상승하면 팽윤(swelling)을 일으키며, CS2를 포함하고 있는 용액에 대해서는 취약하여 40℃이상에서 분해된다.

FT-IR of HDPE

Polypropylene(PP) Isotactic vs syndiotactic polymers Ziegler-Natta catalyst, Nobel Prize in Chemistry in 1963 relative orientation of the alkyl groups in polymer chains Isotactic vs syndiotactic polymers melting point of ~160°C 50

Polyethylene terephthalate(PET(PETE)) melting point of ~260°C Polyester family PET Nylon 51

Polyvinyl chloride (PVC) melting point of ~100-260°C Dioxins 52

Polystyrene(PS) Water-based paint Glass temperature of ~95°C Ziegler-Natta catalyst, Nobel Prize in Chemistry in 1963 relative orientation of the alkyl groups in polymer chains Water-based paint 53

Application of Advanced Composite Materials Application of advanced composite materials in Boeing 757-200 commercial aircraft. Source: Boeing Commercial Airplane Company.

Typical Properties of Reinforcing Fibers

Fibers dominate composite properties

©2003 Brooks/Cole, a division of Thomson Learning, Inc ©2003 Brooks/Cole, a division of Thomson Learning, Inc. Thomson Learning™ is a trademark used herein under license. Comparison of the specific strength and specific modulus of fibers versus metals and polymers.

polymers Naturally occurring polymers Proteins Nucleic acids Cellulose Rubber Synthetic polymers Nylon Dacron Lucite

Natural Polymers 동물 식물 DNA, RNA, polypeptide, Proteins 거미줄, 비단 오리털 (Duck down) 상아 식물 녹말 – starch (polymer of -glucose) 나무 – cellulose (polymer of -glucose) DNA, RNA, polypeptide, Proteins 인간은 자연 고분자를 흉내내려 한다

From glucose cellulose starch

Glucose Why is glucose soluble in water? 62

Two Form of Glucose Glucose  - form Forms linear chains – cellulose Structrural componet of plants, trees  - form Two forms Linear polymer – amylose Branched polymer – amylopectin We can eat both forms but only -form can be digested enzyme (amylase) The -form (cellulose) makes up the fiber in our diet, which is necessary Cellulase digests cellulose can be found in herbivores (cows, goats, etc.) 63

-glucose for cellulose 64

-glucose for starch amylose amylopectin  1,4 glycosidic bond natural organic polymer amylopectin mostly amylose  1,6 glycosidic bond 분말형태

Same glucose monomers? 옥수수를 읽으면서 신문을 먹는다 amylase cellulase enzyme for starch into glucose cellulase enzyme for cellulose into glucose

From amino acid proteins peptides

Naturally Occurring Amino Acids an amino group (-NH2) a carboxyl group (-COOH) Naturally Occurring Amino Acids

Peptide bonding Amino acid → polypeptide → protein Peptide bonds amino carbonyl Peptide bonds Amino Acid Condensation Reaction Tripeptide Peptide bond (amide function group) Proteins determined by the order of the amino acids, how the polymer orders the chain and how the polymers interact with each other 69

Cellulose and starch from glucose Various proteins from amino acid How about DNA and RNA?

DNA : polymer of base pairs

From the natural rubber Polymer industry From the natural rubber To plastic

from rubber trees

History of Polymers : rubber Natural rubber was first scientifically described by C.-M. de la Condamine and François Fresneau of France following an expedition to South America in 1735. The English chemist Joseph Priestley gave it the name rubber in 1770 when he found it could be used to rub out pencil marks. Its major commercial success came only after the vulcanization process was invented by Charles Goodyear in 1839.

Diene Polymers: Natural and Synthetic Rubber Conjugated dienes can be polymerized The initiator for the reaction can be a radical, or an acid Polymerization: 1,4 addition of growing chain to conjugated diene monomer

Natural Rubber A material from latex, in plant sap In rubber repeating unit has 5 carbons and Z stereochemistry of all C=C Gutta-Percha is natural material with E in all C=C Looks as if it is the head-to-tail polymer of isoprene (2-methyl-1,3-butadiene)

Vulcanization Natural and synthetic rubbers are too soft to be used in products Charles Goodyear discovered heating with small amount of sulfur produces strong material Sulfur forms bridges between hydrocarbon chains (cross-links)

Synthetic Rubber Chemical polymerization of isoprene does not produce rubber (stereochemistry is not controlled) Synthetic alternatives include neoprene, polymer of 2-chloro-1,3-butadiene This resists weathering better than rubber

Polymerization Methods Radical Polymerization, 첨가 반응 Step-wise addition of monomers Monomers have double bonds (불포화) Polymers have carbon chain backbone Condensation Polymerization, 축합반응 Generate a small molecule (탈수) Polymer can grow from both ends Polymers have oxygen or nitrogen in backbone Two types of polymer reactions Radical & Condenstation Radical polymerization requires three steps Initiation Propagation Termination Starting material are unsaturated molecules (compound with double bonds) 79

Condensation Polymerization H2O H2O 80

Condensation Polymers Monomers Polymers adipic acid & hexyldiamine Nylon-66 terephthalic acid & phenylenediamine Kevlar terephthalic acid & ethylene glycol Dacron 81

Simulated Kevlar structure 축합중합반응 방탄조끼의 원료 Stephanie L. Kwolek (1965, DuPont)

Comparison of fibers Vectran CNTubes Biosteel - spider silk from goat milk

Polymers around us a polyacrylonitrile * orlon : 일광에 대한 저항성이 강한 것이 특징이며, 그 점에서 나일론의 결점을 보충하여 천막 ·커튼 ·햇빛가리개 ·돛 ·외출복, 우주복 등에 사용 a polyacrylonitrile * lycra : 섬유의 비중이 작고 인장강도 ·굴곡성 ·내마모성 ·내열성이 우수하다. 외과 의료용 편성물, 탄성밴드, 수영복, 산업용 ·군용으로 많이 사용

Polymers around us Polycarbonate polymer Polyurethane Melamine formaldehyde Lexan Bottle

ABS : copolymer made by polymerizing styrene and acrylonitrile in the presence of polybutadiene. Gore-Tex: It was co-invented by Wilbert L. Gore, Rowena Taylor, and Gore's son, Robert W. Gore. It is a porous form of PTFE with a micro-structure characterized by nodes interconnected by fibrils.

Polymers for Health * 의료용 고분자 : 생체 분해성 고분자는 단순 가수분해 또는 효소의 작용으로 분해소멸되는 고분자이다. 대부분의 합성고분자는 분해되지 않지만, 일부 지방족 폴리에스터 혹은 폴리카보네이트들은 가수분해에 의해 천천히 분해된다. 치과용 고분자로는 구강내 특수한 상황으로 요구특성이 매우 까다로와, PMMA와 bis-GMA계 복합재가 주종을 이룬다. 혈액투석기, 혈장분리기, 인공심폐기등에 쓰이는 분리막 소재로는 PMMA, PP, PAN, polysulfone, cellulose, PVA, PE, poly(ethylene-co-vinylacetate)등이 사용된다. 인공피부 인공 뼈 인공혈관 * 콘택트 렌즈 : 초기에 개발된 PMMA는 투명하고 기계적 강도는 우수하나 착용감이 나쁘고 산소투과성이 거의 없으므로 시장에서 쇠퇴하고, 최근에 많이 쓰이는 경질 콘택트 렌즈에 재료로서 PHEMA(poly hydroxyethylmethacrylate)계 친수성 하이드로젤을 사용한다. PMMA에 비하여 기계적 강도는 떨어지지만, 친수성이며 산소투과성이 높아 널리 사용된다.

Conductive polymer polyacetylene Polyphenylenevinylene(PPV) Transparent conductor Poly(3,4-ethylene-dioxythiophene) or PEDOT polyaniline (X = N, NH) and polyphenylene sulfide (X = S). polythiophene (X = S) and polypyrrole (X = NH)

Biodegradable polymer 인공장기를 키우는 틀로 활용 생 분해성 고분자를 이용해 귀의 형태를 만들고, 귓바퀴가 없는 사람의 귀 세포를 떼어내 배양액에서 키우면, 시간이 지나 틀을 유지하던 생 분해성 고분자는 분해되고 그곳에 귀의 형태를 가진 세포들이 자란다. 이렇게 만들어진 귀를 실험용 누드마우스나 사람에게 이식할 수 있다.

비니루, 비닐 ‘비니루’ 라는 표현은 vinyl (비닐) 이라는 영어의 일본식 표현이다. 비닐장판, 비닐우산, 비닐 장갑 등 ‘비닐’ 을 사용한 예들이 많지만, 이렇게 하는 것은 반쯤 모자라는 것으로 덜 과학적인 표현이다. 화학에서 ‘비닐’ 이란 원자단의 하나로 화학식으로 표현하면 CH2〓CH─ 이며, CH─ 에 무언가가 결합하여야 온전한 화합물이 되기 때문이다. 예로 여기에 H가 결합하면 에틸렌(CH2〓CH2)이 되고, 염소가 결합하면 염화비닐(CH2〓CHCl), 페닐기가 결합하면 스티렌(CH2〓CH-C6H5)이 된다. 이들이 길게 연결하여 폴리에틸렌(PE), 폴리염화비닐(PVC), 폴리스티렌(PS)을 만든다. 우리가 통상 사용하는 비닐이라는 명칭은 석유화학 필름 제품에 두루 쓰고 있지만 이들 중에는 ‘비닐’이 아닌 것도 있다. 예로 나일론은 화학적으로는 비닐과는 거리가 있다. 오히려 나일론은 비단과 가깝다.