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Questions and Answers
What are polymers primarily made of?
What are polymers primarily made of?
Which of the following is a method of polymer classification?
Which of the following is a method of polymer classification?
Which name is standardized and proposed by the American Chemical Society?
Which name is standardized and proposed by the American Chemical Society?
What is the process of forming large molecules from small molecules called?
What is the process of forming large molecules from small molecules called?
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Which of the following is not a type of name used for polymers?
Which of the following is not a type of name used for polymers?
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What characterizes hydrocarbon polymers?
What characterizes hydrocarbon polymers?
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Which is NOT a classification criteria for polymers?
Which is NOT a classification criteria for polymers?
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What is the term for a molecule or distinct segment that makes up a polymer?
What is the term for a molecule or distinct segment that makes up a polymer?
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What distinguishes a homopolymer from a copolymer?
What distinguishes a homopolymer from a copolymer?
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Which of the following characteristics is true for linear polymers?
Which of the following characteristics is true for linear polymers?
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What is the primary difference between low density polyethylene (LDPE) and high density polyethylene (HDPE)?
What is the primary difference between low density polyethylene (LDPE) and high density polyethylene (HDPE)?
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Which type of polymer is least likely to have low density and low melting points?
Which type of polymer is least likely to have low density and low melting points?
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What type of polymer structure would you expect to find in materials that are permanently hard when heated?
What type of polymer structure would you expect to find in materials that are permanently hard when heated?
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What property is most affected by the chain structure of a polymer?
What property is most affected by the chain structure of a polymer?
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Which statement about non-hydrocarbon polymers is accurate?
Which statement about non-hydrocarbon polymers is accurate?
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Which statement is true regarding the structure of branch polymers?
Which statement is true regarding the structure of branch polymers?
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What defines tacticity in polymers?
What defines tacticity in polymers?
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Which type of tacticity allows for chain folding and crystalline structure formation?
Which type of tacticity allows for chain folding and crystalline structure formation?
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What type of intramolecular interaction involves the attraction between hydrogen and oxygen atoms?
What type of intramolecular interaction involves the attraction between hydrogen and oxygen atoms?
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Which of the following characteristics is NOT associated with van der Waals forces?
Which of the following characteristics is NOT associated with van der Waals forces?
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Which configuration describes an isotactic polymer?
Which configuration describes an isotactic polymer?
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Which of the following is classified as a thermosetting polymer?
Which of the following is classified as a thermosetting polymer?
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What is a common result of strong hydrogen bonding in polymers?
What is a common result of strong hydrogen bonding in polymers?
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What characteristic differentiates thermoplastic materials from thermosetting materials?
What characteristic differentiates thermoplastic materials from thermosetting materials?
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What defines an atactic polymer?
What defines an atactic polymer?
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What type of molecular attraction is primarily responsible for the interactions governing polymer entanglement?
What type of molecular attraction is primarily responsible for the interactions governing polymer entanglement?
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Which of the following polymers is an example of an elastomer?
Which of the following polymers is an example of an elastomer?
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What defines a copolymer?
What defines a copolymer?
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Which type of copolymer has monomers arranged in alternating positions?
Which type of copolymer has monomers arranged in alternating positions?
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Which of the following is an example of a block copolymer?
Which of the following is an example of a block copolymer?
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Which characteristic is true of random copolymers?
Which characteristic is true of random copolymers?
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In the context of copolymers, what does 'graft copolymer' refer to?
In the context of copolymers, what does 'graft copolymer' refer to?
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What are the primary interactions that contribute to the physical properties of polymer?
What are the primary interactions that contribute to the physical properties of polymer?
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How is a polymer's number-average molecular weight, $M_n$, primarily determined?
How is a polymer's number-average molecular weight, $M_n$, primarily determined?
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Which formula correctly represents the calculation of weight-average molecular weight, $M_w$?
Which formula correctly represents the calculation of weight-average molecular weight, $M_w$?
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What is the significance of molecular weight distribution in polymers?
What is the significance of molecular weight distribution in polymers?
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Considering a polymer sample with 5 moles of polymer molecules at 40.0 g/mol and 15 moles at 30.0 g/mol, what is the number-average molecular weight $M_n$?
Considering a polymer sample with 5 moles of polymer molecules at 40.0 g/mol and 15 moles at 30.0 g/mol, what is the number-average molecular weight $M_n$?
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What role do temporary fluctuating dipoles play in molecular behavior?
What role do temporary fluctuating dipoles play in molecular behavior?
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Which molecular weight calculation accounts for both the molecular weights and the number of molecules present?
Which molecular weight calculation accounts for both the molecular weights and the number of molecules present?
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How does chain entanglement contribute to the properties of polymers?
How does chain entanglement contribute to the properties of polymers?
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Study Notes
Definition, Nomenclature, and Polymerization
- Polymers are macromolecules built from smaller repeating units called monomers.
- Polymerization is the process of joining monomers together through covalent bonds.
- Standard nomenclature for polymers is established by ACS and IUPAC.
- Common and trade names are often used based on historical models or industry practices.
Classification of Polymers
- Classified by:
-
Type of Monomer:
- Hydrocarbon polymers: Contain carbon and hydrogen (e.g., Polypropylene)
- Non-hydrocarbon polymers: Contain atoms other than carbon and hydrogen (e.g., Poly(methyl methacrylate))
-
Chain Structure:
- Linear: Single continuous chain with high density, high melting point, and thermoplastic properties (e.g., HDPE)
- Branched: Side chains connected to the main chain with lower density, lower melting point, and thermoplastic properties (e.g., LDPE)
- Crosslinked: 3D networks formed by crosslinks between chains, resulting in rigidity, high hardness, and thermosetting properties
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Property:
- Thermoset: Crosslinked and rigid, hardens upon heating (e.g., epoxies, phenolics, polyimides)
- Thermoplastic: Uncrosslinked, melts upon heating and solidifies upon cooling (e.g., acrylics, nylon, polyethylene, PVC)
- Elastomer: Flexible to rigid, exhibiting properties of both plastics and rubbers (e.g., ENR, SBR, NBR, PDMS)
-
Type of Monomer:
Copolymer and Copolymerization
- Copolymer: Polymer composed of two or more different types of monomers.
- Copolymerization: Process of synthesizing a copolymer.
- Types of Copolymers:
- Alternating: Monomers alternate along the backbone
- Block: Groups of monomers occur together
- Random: Monomer segments arranged randomly
- Graft: Chain of one polymer attached to a different polymer type
Geometric Isomer and Tacticity
- Geometric Isomer: Different spatial arrangement of atoms within a molecule (e.g., cis-but-2-ene and trans-but-2-ene)
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Tacticity: Stereochemical arrangement of units in the main chain.
- Isotactic: Functional groups arranged on the same side of the carbon skeleton
- Syndiotactic: Functional groups arranged in an alternating fashion
- Atactic: Functional groups arranged randomly
Inter and Intra-molecular Attraction in Polymer
- Strongest force: Covalent bonds within polymers
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Interchain binding: Weaker forces that hold polymer chains together
- Hydrogen Bonds: Relatively strong dipole interactions.
- Van der Waals Forces: Weak forces arising from temporary dipoles.
- Chain Entanglement: Long chains intertwine, contributing to strength and resilience.
Molecular Weight and Molecular Weight Distribution
- Molecular weight: Average length of polymer chains in a bulk resin.
- Different molecular weight calculation methods:
- Number-average molecular weight (Mn): Calculates the average chain length.
- Weight-average molecular weight (Mw): Reflects the statistical size of the polymer.
- Viscosity-average molecular weight (Mv): Measure related to the viscosity of the polymer solution.
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Description
Explore the essential concepts of polymers, including their definition, nomenclature, and the process of polymerization. This quiz covers the classification of polymers based on monomer types and chain structures, helping you understand the diversity and applications of these macromolecules.
