Learning target: I can use evidence from a passage to describe where four synthetic materials came from, what problems they solved for society, and what new problems they created.
Read the passage once without stopping. Read it a second time with a pencil: number the paragraphs 1 to 7 and underline every date and every material name. Answer in complete sentences. When a question asks for evidence, quote or closely paraphrase the passage and write the paragraph number in parentheses. Two questions ask you to weigh a benefit against a cost; give both sides a fair hearing before you decide.
You will need: This worksheet, Pencil, Scrap paper for the chart
[1]Until the early 1900s, nearly everything a person wore, built with or rode on came from a plant, an animal or a mine and was used much as nature made it. That changed in 1907. Leo Baekeland, a Belgian-born chemist working in New York, heated phenol, a substance from coal tar, with formaldehyde under pressure. The reaction produced a hard, dark resin that could be molded while hot and then never melted again. He named it Bakelite. Because it did not conduct electricity and did not soften in a warm room, it became the material of radio cases, telephone handsets and light switches.
[2]The next leap came at DuPont, where a team led by Wallace Carothers was studying how small molecules could be linked end to end into enormous chains. In 1935 they made nylon, a polymer that could be drawn into a strong, thin thread. Its building blocks came, through several chemical steps, from coal tar at first and later from petroleum. DuPont announced nylon publicly in October 1938; the first product sold that year was a toothbrush with nylon bristles. Nylon stockings went on sale across the United States in May 1940 and sold out quickly.
[3]Why the rush? Silk stockings snagged and tore easily, and the silk came from silkworms raised mostly in Japan, across an ocean. Nylon stockings were stronger and dried quickly. The trade-off was invisible at the time: the new material came from a resource that cannot be regrown, and a nylon stocking thrown away does not rot the way a silk one does. When the United States entered World War II in December 1941, almost all nylon went to parachutes, ropes and tire cords, and stockings vanished from stores.
[4]Rubber was the greater emergency. Natural rubber is made from latex, the sap of a tree grown on plantations in Southeast Asia. Early in 1942 Japanese forces took control of that region, and the United States lost access to roughly nine tenths of its rubber supply, with only about a year's worth stockpiled. Chemists already knew that two small molecules, styrene and butadiene, could be joined into long, springy chains that behaved like rubber. Within three years, dozens of new factories were making synthetic rubber from petroleum and grain alcohol, hundreds of thousands of tons a year.
[5]The two wartime substitutes had different fates. During the First World War, sugar had been scarce and many people switched to the synthetic sweetener saccharin, but when sugar returned, most switched back. Synthetic rubber did not go away. It could be made at home, its properties could be adjusted for different jobs, and the factories already existed. Today more than half of the rubber used in the world is synthetic. Natural rubber has not disappeared, though: it stays strong when it is flexed and heated over and over, which is why aircraft tires are still made mostly from the tree-grown kind.
[6]In 1941 two British chemists, John Whinfield and James Dickson, linked two building blocks, today made from petroleum, into a polymer called PET. Spun into fiber in the 1950s, it made shirts that resisted wrinkles. In 1973 a DuPont engineer, Nathaniel Wyeth, patented a way to blow PET into a bottle strong enough to hold the pressure of a fizzy drink, and by the late 1970s soft drinks came in clear, light, shatterproof PET bottles.
[7]Every one of these materials solved a real problem, and every one created a new problem that nobody set out to make. Bakelite cannot be remelted, so it is very hard to recycle. Nylon and polyester do not rot, so a shirt can last for decades or longer in a landfill. Washing polyester sheds tiny fibers into wastewater. Of the PET bottles thrown away in the United States in 2018, fewer than a third, about 29 percent, were collected for recycling. Engineers are now working on the second round of problems: plastics that break down, fibers that shed less, bottles that are easier to collect. The lesson is not that natural materials are good and synthetic ones are bad. It is that every material has a source and an ending, and a fair judgment has to look at both.
Before answering, draw a chart with four rows (Bakelite, nylon, synthetic rubber, PET) and four columns: the year it appeared, the natural resource it came from, the problem it solved, the problem it caused. Fill it in from your underlined dates and material names. Questions 1, 3, 5 and 8 can be answered almost directly from the chart; the rest ask you to add the reason behind an entry.
Paragraph 7 says engineers are working on 'the second round of problems.' Pick one of the three examples (plastics that break down, fibers that shed less, bottles that are easier to collect) and write a paragraph predicting what new problem that solution might create in turn. Base your prediction on the pattern in the passage: a material's benefits show up right away, and its costs show up later and often somewhere else. Then write one question you would want answered before calling the new solution a success.