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What is a polymer?
What is a polymer?
A polymer is a molecular compound that can be distinguished by a high molar mass, ranging into thousands and even millions of mass and they are made up of many repeating units.
What are the two main types of polymers and provide an example for each?
What are the two main types of polymers and provide an example for each?
The two main types of polymers are thermoplastic and thermosetting polymers. Thermoplastics can be melted and reshaped repeatedly, such as polyethylene. Thermosetting polymers harden permanently when heated, such as epoxy resin.
Natural polymers have been around since life itself began.
Natural polymers have been around since life itself began.
True (A)
How are polymers created from monomers?
How are polymers created from monomers?
What is the name given to a polymer that is made up of only one type of monomer? (Select all that apply)
What is the name given to a polymer that is made up of only one type of monomer? (Select all that apply)
What are the two main types of homopolymers?
What are the two main types of homopolymers?
What is a common raw material used for the production of synthetic polymers?
What is a common raw material used for the production of synthetic polymers?
What is the name given to the gigantic molecules in polymers?
What is the name given to the gigantic molecules in polymers?
What is the backbone of a carbon-chain polymer?
What is the backbone of a carbon-chain polymer?
What type of bond connects the atoms within a polymer molecule?
What type of bond connects the atoms within a polymer molecule?
What is the chemical formula for ethylene?
What is the chemical formula for ethylene?
What is the name of the process that transforms ethylene gas into polyethylene?
What is the name of the process that transforms ethylene gas into polyethylene?
What type of material is polyethylene?
What type of material is polyethylene?
What is an active center in polymerization?
What is an active center in polymerization?
What is the chemical formula for tetrafluoroethylene?
What is the chemical formula for tetrafluoroethylene?
What is the trade name for polytetrafluoroethylene?
What is the trade name for polytetrafluoroethylene?
What is the chemical formula for vinyl chloride?
What is the chemical formula for vinyl chloride?
What is the meaning of the letter "R" in the general formula for polymers?
What is the meaning of the letter "R" in the general formula for polymers?
What four types of molecular structures are described in the text?
What four types of molecular structures are described in the text?
What type of polymer structure is characterized by repeat units joined together end to end in single chains?
What type of polymer structure is characterized by repeat units joined together end to end in single chains?
What type of polymer structure is characterized by side branches?
What type of polymer structure is characterized by side branches?
What type of polymer structure is characterized by adjacent linear chains joined together by covalent bonds?
What type of polymer structure is characterized by adjacent linear chains joined together by covalent bonds?
What type of polymer structure is characterized by multifunctional monomers forming three or more active covalent bonds, creating a three-dimensional network?
What type of polymer structure is characterized by multifunctional monomers forming three or more active covalent bonds, creating a three-dimensional network?
What is the other name for partially crystalline polymers?
What is the other name for partially crystalline polymers?
What is an amorphous region in a polymer?
What is an amorphous region in a polymer?
What is the name of a unit cell for polyethylene?
What is the name of a unit cell for polyethylene?
The length of polymer chains has no effect on polymer properties.
The length of polymer chains has no effect on polymer properties.
Polymers with very short chains or a low molecular weight exist as liquids at room temperature.
Polymers with very short chains or a low molecular weight exist as liquids at room temperature.
Polymers with molecular weights of approximately 1000 g/mol exist as waxy solids or soft resins.
Polymers with molecular weights of approximately 1000 g/mol exist as waxy solids or soft resins.
What is the range of molecular weights for polymers that are sometimes termed high polymers?
What is the range of molecular weights for polymers that are sometimes termed high polymers?
What is the molecular weight of the repeat unit of PVC?
What is the molecular weight of the repeat unit of PVC?
What is the degree of polymerization of PVC?
What is the degree of polymerization of PVC?
What is the weight-average molecular weight of PVC?
What is the weight-average molecular weight of PVC?
What is the name for a polymer that is composed of two or more different repeat units?
What is the name for a polymer that is composed of two or more different repeat units?
What are the four types of copolymer arrangements described in the text? (Select all that apply)
What are the four types of copolymer arrangements described in the text? (Select all that apply)
Synthetic rubbers are usually copolymers?
Synthetic rubbers are usually copolymers?
The atomic arrangement in polymers is simpler than in metals and ceramics.
The atomic arrangement in polymers is simpler than in metals and ceramics.
What is polymer crystallinity?
What is polymer crystallinity?
The degree of crystallinity in polymers can range from completely amorphous to almost entirely crystalline.
The degree of crystallinity in polymers can range from completely amorphous to almost entirely crystalline.
Which type of material typically exhibits a higher degree of crystallinity: metals or polymers?
Which type of material typically exhibits a higher degree of crystallinity: metals or polymers?
The degree of polymer crystallinity can significantly affect its properties.
The degree of polymer crystallinity can significantly affect its properties.
What are the two most common types of polymers that form with linear structures?
What are the two most common types of polymers that form with linear structures?
Flashcards
Polymer
Polymer
A large molecule composed of many repeating structural units called monomers, with molecular weights often reaching thousands or millions.
Monomer
Monomer
The basic building block of a polymer, a small molecule that repeats to form a long chain.
Homopolymer
Homopolymer
A polymer formed from only one type of monomer.
What are some examples of common homopolymers?
What are some examples of common homopolymers?
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Macromolecule
Macromolecule
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Backbone of a polymer chain
Backbone of a polymer chain
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Side bonds in polymers
Side bonds in polymers
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What is the monomer of polyethylene?
What is the monomer of polyethylene?
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How is polyethylene formed?
How is polyethylene formed?
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What is the difference between ethylene and polyethylene?
What is the difference between ethylene and polyethylene?
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What is Teflon?
What is Teflon?
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What is PVC?
What is PVC?
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Linear polymer
Linear polymer
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Branched polymer
Branched polymer
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Crosslinked polymer
Crosslinked polymer
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Network polymer
Network polymer
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What are the six most common polymers?
What are the six most common polymers?
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Number-average molecular weight (Mn)
Number-average molecular weight (Mn)
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Weight-average molecular weight (Mw)
Weight-average molecular weight (Mw)
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Degree of Polymerization (DP)
Degree of Polymerization (DP)
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What is the relationship between molecular weight and properties?
What is the relationship between molecular weight and properties?
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Thermoplastic polymer
Thermoplastic polymer
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Thermosetting polymer
Thermosetting polymer
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What is the key structural difference between thermoplastics and thermosets?
What is the key structural difference between thermoplastics and thermosets?
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Copolymer
Copolymer
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Random copolymer
Random copolymer
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Alternating copolymer
Alternating copolymer
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Block copolymer
Block copolymer
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Graft copolymer
Graft copolymer
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Polymer crystallinity
Polymer crystallinity
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Amorphous polymer
Amorphous polymer
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Semicrystalline polymer
Semicrystalline polymer
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Study Notes
Polymers
- Polymers are molecular compounds characterized by high molar masses (ranging into thousands and even millions).
- They are composed of repeating units.
- Synthetic polymers were developed in the early 20th century, significantly impacting various applications.
- Natural polymers have existed since life's origin; examples include cellulose, starch, natural rubber, and DNA.
- Monomers (mono meaning "one"; meros meaning "unit") are small molecules used to synthesize polymers.
- A polymer's structure influences its behavior under heat.
- Homopolymers are created from one type of monomer, while copolymers are made from two or more different monomers.
- Examples of homopolymers include polyethylene and poly(vinyl chloride) (PVC). Teflon is an example of a homopolymer.
- Polymers can be sourced from crude oil, a vital raw material in producing various carbon-based products.
- Polymer molecules are large and referred to as macromolecules.
- Within each molecule, atoms are bonded by covalent interatomic bonds in a polymer chain.
- Carbon atoms frequently bond to two adjacent carbon atoms.
- Ethylene (C2H4) is a gas that can be transformed into polyethylene (PE) under specific conditions.
- Polymer chains are formed by the sequential addition of monomer units.
- Additional properties are affected by the length of polymer chains. For very lengthy polymer chains with a large molecular weight (around 100,000 g/mol), the melting/softening point increases).
- With smaller molecular weights (around 1000 g/mol) the polymers exist as a wax or soft resin.
Molecular Weight and Degree of Polymerization
- Polymer chains vary in length, leading to a distribution of molecular weights.
- Average molecular weight (Mn) is calculated from the measurement of physical characteristics like viscosity and osmotic pressure.
- The number-average molecular weight (Mn) takes into account the number of chains within each size range.
- The weight-average molecular weight (Mw) considers the weight/mass fraction of molecules in each size range.
- The degree of polymerization (DP) represents the average number of repeat units in a polymer chain, related to the number-average molecular weight.
Thermoplastic and Thermosetting Polymers
- Polymer behavior with heat defines thermoplastic and thermosetting polymers.
- Thermoplastics soften when heated, liquefy, and harden when cooled. This process is reversible, repeating many times.
- For thermoplastics, high temperatures can cause irreversible degradation.
- Thermosetting polymers do not soften when heated. These are network polymer chains with covalent crosslinks. This structure makes them permanently hard after formation.
- Excessively high heats during thermoset processing will cause the severing of bonds, degrading the polymer.
Copolymers
- Copolymers are made from two or more different monomers.
- Different arrangements (random, alternating, block, or graft) of repeat units can affect the copolymer's properties.
Polymer Crystallinity
- Crystalline polymers have complex atomic arrangements unlike metals and ceramics, which involve molecules rather than atoms or ions.
- Crystalline structures are based on unit cells (often complex).
- Polyethylene's unit cell structure has an orthorhombic geometry.
- Amorphous regions are common in polymers due to chain misalignments, hindering strict ordering.
- Crystallinity can vary from completely amorphous to nearly 95% crystalline.
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Description
Dive into the fascinating world of polymers, molecular compounds with high molar masses. Explore the differences between synthetic and natural polymers, and learn about monomers and their role in polymer synthesis. This quiz will help you understand the structures, types, and applications of various polymers.
