Introducing Polymers

Comprehensive question-and-answer flashcards covering natural and synthetic polymers, polymerization reactions, historical polymer developments, and environmental impacts.

What is silk and which organism produces it?

Silk is a natural polymer fibre produced when caterpillars of Bombyx mori moths make their cocoons.

How do the physical properties of a silk fibre compare to a steel wire of similar size?

A silk fibre is thinner than a human hair, but much stronger and lighter in weight than a similar-sized steel wire.

What is the definition of a polymer?

A large, usually chain-like molecule that is built from small molecules called monomers.

What is a monomer?

One of the repeating small molecules that make up polymers.

What is a homopolymer?

A polymer formed by reactions involving a single type of monomer.

What occurs during an addition reaction to form polyethene from ethene?

The double bond in each ethene monomer is converted into a single bond, freeing up two electrons that form carbon-carbon single bonds with other monomers.

What are two examples of homopolymers formed by addition reactions other than polyethene?

Polypropene (polypropylene) and polystyrene.

What is a copolymer?

A polymer made of two or more different types of monomers combined to form the polymer chain.

What characterizes a condensation polymerization reaction?

Monomers join to form polymer chains while a small molecule, such as a molecule of water ($H_2O$), is eliminated as each new bond forms.

What type of biological polymer is silk, and what monomers combine to form it?

Silk is a protein formed by condensation reactions of amino acid monomers, such as lysine, alanine, and leucine.

Which plant homopolymers are composed of the monomer glucose?

Starch and cellulose.

What are the monomer repeating units of DNA, and what three components make up each monomer?

The monomers are nucleotides, each consisting of a base, a phosphate, and a sugar.

What are the typical monomer sources used for manufacturing synthetic polymers?

Monomers sourced from plants or from petrochemicals.

Who developed vulcanized rubber in 1839, and what chemical process was used?

Charles Goodyear developed it by heating natural rubber sap with sulfur, which made it harder and raised its melting point.

What was the first fully synthetic polymer, and who invented it in 1909?

Bakelite, invented by Leo Hendrik Baekeland.

Why was celluloid invented in 1868, and what entertainment medium did it advance?

It was invented to replace ivory in billiard balls, and celluloid film played a central role in the development of the movie industry.

Who invented vinyl (PVC) in 1929, and what novel audio use did it serve?

Waldo Semon invented vinyl (PVC), which became the first durable material used to record and play back music.

Who invented nylon in 1935, and what was it designed to replace?

Wallace Carothers invented nylon to replace silk in parachutes and stockings.

What was Ralph Whiley's original application for Saran when he invented it in 1933?

It was sprayed as a coating onto fighter planes to protect surfaces against corrosion from sea salt.

How was the removable adhesive for notepaper developed by Spencer Silver and Arthur Fry?

In 1968, Spencer Silver created a weak adhesive with no apparent use; in 1974, Arthur Fry suggested applying it to paper squares so they could stick securely yet be easily removed.

What marine environmental discovery in 1997/1998 motivated polymer chemists to develop biodegradable plastics?

The existence of the Great Pacific Garbage Patch was predicted and confirmed.

What are two major health and environmental concerns regarding synthetic polymers?

The breakdown of polymers during use potentially releasing carcinogenic compounds into food or water, and their inability to degrade quickly, remaining in the environment for decades or centuries.

What is the full chemical name of the hard plastic monomer abbreviated as BPA?

2,2-bis(4-hydroxyphenol)propane.