Chapter 18 Chemistry and materials Diamond Paper, plastic, metals, glass, ceramics
Chapter 18 Chemistry and Materials Diamond Paper, plastic, metals, glass, ceramics
18.1 Paper is made of cellulose fibers Paper was first made HARDWOOD FIBERS in China as early as AD 100, of mulberry bark, and then introduced to Western SOFTWOOD FIBERS world by arabs in eighth century. The first paper mills were built in Spain in 11th centum ry
18.1 Paper is made of cellulose fibers • Paper was first made in China as early as AD 100, of mulberry bark, and then introduced to Western world by Arabs in eighth century. The first paper mills were built in Spain in 11th century
The use of wood to produce paper was started in USA Additives such as rosin(松香) and alum(明矾)Were added to strengthen paper and make it accept ink well Chlorine as used to bleaching paper and titanium dioxide (钛白粉) was used to make the paper white. Acidic paper, acid-free paper and alkaline paper Plants alternative to trees: willow(tp), kenaf(K). They usually have high fiber content and grow fast 70 million tons of paper are used in USA: one person 230 kilograms or six trees
• The use of wood to produce paper was started in USA. • Additives such as rosin (松香) and alum (明矾) were added to strengthen paper and make it accept ink well. Chlorine as used to bleaching paper and titanium dioxide （钛白粉）was used to make the paper white. • Acidic paper, acid-free paper and alkaline paper • Plants alternative to trees: willow (柳), kenaf (麻). They usually have high fiber content and grow fast. • 70 million tons of paper are used in USA: one person 230 kilograms or six trees
18.2 The development of plastics involved experimentation and discovery · The search for Isoprene a lightweight, nonbreakable lymerization moldable polyisoprene material began with the Fig185 isoprene molecules invention of react with one another to vulcanized form polyisoprene, the fundamental chemical unit rubber(硫化橡 of natural rubber which 胶) comes from rubber trees
18.2 The development of plastics involved experimentation and discovery • The search for a lightweight, nonbreakable, moldable material began with the invention of vulcanized rubber (硫化橡 胶). + + isoprene polyisoprene polymerization Fig18.5 isoprene molecules react with one another to form polyisoprene, the fundamental chemical unit of natural rubber, which comes from rubber trees
Charles goodyear discovered the rubber vulcanization in 1837 Polymer strands Fig18.6 (a) when stretched the individual poly-isoprene strands in (a)Original form Stretched with little tendency natural rubberlip past to snap back to original form one another and the rubberstays stretched Polymer strands (b)when vulcanized rubber is stretched the sulfur crosslinks hold the strands together allowing the rubber to return to its original shape (b)Original form with disulfide Stretched with great tendency to cross-inks snap back because of cross-links
Charles Goodyear discovered the rubber vulcanization in 1837. (a) Original form Stretched with little tendency to snap back to original form Stretched with great tendency to snap back because of cross-links (b) Original form with disulfide cross-links Fig18.6 (a) when stretched, the individual poly-isoprene strands in natural rubber slip past one another and the rubber stays stretched. (b) when vulcanized rubber is stretched, the sulfur cross-links hold the strands together, allowing the rubber to return to its original shape Polymer strands Polymer strands
Nitrocellulose and celluloid Nitrate group Fig 18.7 O-NO nitrocellulose. also O一NO known as cellulose O nitrate, is highly O O combustible because NO O of its many nitrate ON NO2 groups, which facilitate oxidation O,N Nitrocellulose(cellulose nitrate)
Nitrocellulose and celluloid Fig 18.7 nitrocellulose, also known as cellulose nitrate, is highly combustible because of its many nitrate groups, which facilitate oxidation Nitrate group Nitrocellulose (cellulose nitrate)
Bakelite and phenolic resin(酚醛树脂) HH CH2 CH? OH Formaldehyde CH 12 OH CHy. polymerization CH OH Fig 18.9 the molecular network of bakelite shown in two dimensions Phenol-formaldehyde The actual structure resin(Bakelite) projects in all three dimensions. The first Polymers win in World War ll handset telephones were made of bakelite Synthetic rubber, radar, tank and tent Polymer and environment
Bakelite and phenolic resin (酚醛树脂) Polymers win in World War II Synthetic rubber, radar, tank and tent Polymer and environment Fig 18.9 the molecular network of bakelite shown in two dimensions. The actual structure projects in all three dimensions. The first handset telephones were made of bakelite OH CH2 CH2 CH2 OH OH CH2 CH2 OH OH CH2 CH2 OH CH2 OH CH2 OH OH C H H O OH Formaldehyde phenol polymerization Phenol-formaldehyde resin (Bakelite)
18.3 Metals come from the Earth's limited supply of ores Metallic bond is responsible for the high conductivity and high gross Fig18 14 metal ions are held together by freely flowing electrons These loose electrons form a kind of electronic fluid"that flows through the lattice of positively charged ions
18.3 Metals come from the Earth’s limited supply of ores Metallic bond is responsible for the high conductivity and high gross. Fig18.14 metal ions are held together by freely flowing electrons. These loose electrons form a kind of “electronic fluid” that flows through the lattice of positively charged ions
The form in which a metal is most likely to be found in nature is a function of its position in periodic table Sulfides Uncombined Chlorides Other compounds 141516 see caption 3A 4A 5A 6A 7A Oxid Mg 678910 c×m、smsc M Te Pd A m山mw Ir Pt Au H I P m Fig 18 19 which compound of a metal is most prevalent in nature is related to the metals position in the periodic table
The form in which a metal is most likely to be found in nature is a function of its position in periodic table. Fig 18.19 which compound of a metal is most prevalent in nature is related to the metals position in the periodic table
Metal-containing compounds can be converted to metals Anode M Transforming the metal- containing compoundto a metal is less energy Sheets of Anode sludge Sheets of ntensive Solution copper containing oure Transforming the metal CUSO4 copper containing compoundto a metal is more energy Fig 18.21 high-purity copper is recovered by intensive electrolysis. Pure copper metal deposits on the negative electrode as copper ions in solution gain electrons. The source of these copper ions is a positively charged electrode made of Impure copper
Metal-containing compounds can be converted to metals Sheets of impure copper Sheets of pure copper Solution containing CuSO4 Transforming the metalcontaining compound to a metal is less energy intensive Transforming the metalcontaining compound to a metal is more energy intensive Fig 18.21 high-purity copper is recovered by electrolysis. Pure copper metal deposits on the negative electrode as copper ions in solution gain electrons. The source of these copper ions is a positively charged electrode made of impure copper
