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Definition
| high molecular weight molecules comprised of many similar building blocks. |
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| any substance that can be converted into a polymer |
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| basic building block of a polymer. Each SU is derived from a monomer. Sometimes the SU and monomer have the same molecular weight |
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| a structural unit or combination of structural units that repeats along a polymer chain. |
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| All polymers have identifiable _____, but not all polymers have _____. Think of examples |
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| structural units; repeat units. |
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| a polymer compromised of one structural unit or one repeat unit |
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| a polymer compromised of more than one structural unit or a combination of structural units/ |
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| Give some examples of chain architecture. |
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Definition
| linear; branched; star; dendrimer |
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| Chemical crosslinks. Give examples |
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Definition
| covalent linkages between chains- fully crosslinked polymers are insoluble and infusible. disulfide linkages in vulcanized rubber and proteins. |
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| Give examples of a type of polymer architecture that makes use of end chemistry |
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| defines the number, types and sequence of structural units along a chain |
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| Ultimately ___ determines all higher order structures of a polymer |
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Definition
| local spatial arrangement (conformation) of structural units in a chain. (ex helical, planar zig zag, and random conformations) |
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Definition
| overall 3D arrangement of a polymer chain (can include different secondary conformations) |
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| sometimes called supramolecular structure. 3D arrangement of multiple chains (ex: a self-assembled cluster compromised of multiple protein molecules) |
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Term
| Glass transition temperature |
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Definition
| the temperature where you have onset of long-range molecular motion in the amorphous regions of a polymer. The glass transition temperature is determined by barriers to chain rotation, both intra and intermolecular. Key controlling parameters include strength of intermolecular forces, steric effects, close packing abilities of chains |
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Definition
| the temperature at which crystalline regions of a polymer undergo a transition from the ordered to the disordered state. |
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Definition
| tells you how much the molecular weight of polymers varies in experimental sample. PDI = 1 means that every single chain has the exact same molecular weight. PDI for synthetic polymers can range from 1.03 to over 30 |
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Term
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Definition
| covalent bonds; energy to break the bond typically in the 50-200 kcal/mol range. |
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| How many electrons does C like to have? N? O? |
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Definition
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| What determines the strength of inter and intramolecular forces? |
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Definition
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Definition
| .5-2 kcal/mol dissociation energies. Associated with non-polar molecules, forces due to induced dipoles |
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Definition
| 1.5-4kcal/mole disassociation energies, forces due to permanent dipoles |
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Term
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Definition
| 3-8kcal/mol disassociation energues, possible when H is attached to a more elctronegative atom: ), N or F. Occurs due to a high charge to mass ratio on the H atom |
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Term
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Definition
| 10-20 kcal/mol disassociation energies, forces due to formal charges on molecules |
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Definition
| special case in aqueous environments, where non-polar segments associate because they do not like water. |
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Definition
| molecules with the same number and types of atoms but with distinguishably different structures |
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Definition
| isomers that have the same empirical formula but different structural formula |
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Term
| What effect does branching generally have on the melting point? |
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Definition
| branching generally decreases the melting point |
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Term
| Give some examples of H bond donor/acceptor pairs |
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Definition
| alcohol and carbonyl; alcohol and alcohol; amine and carbonyl; amine and pyridine |
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Term
| Why can amine and carboxylic acid functional groupings act as solid electrolytes? |
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Definition
| They become charged in specific pH environments. The amine grouping takes on a positive charge in basic environments and the carboxilic acid group loses a proton to take on a neg. charge in acidic environments |
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Term
| Give an example of a common protein that has both an H bond acceptor and H bond donor built into the structure |
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Definition
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Definition
| a functional group or other structure changes location on a parent structure |
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Definition
| isomers that have the same structural formula but different spatial arrangements of atoms |
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Definition
| stereoisomers that can only be interconverted by breaking of bonds |
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| cis/ trans geometric isomers |
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Definition
| configurational isomer where atoms are arranged differently about a double bond |
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Definition
| a configuration isomer where atoms are arranged differently about an sp3 hybridized carbon. |
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Definition
| isomers that can be interconverted by bond rotation about single bonds. |
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| Which conformational isomers are generally energetically favored |
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Definition
| staggered arrangements (trans, gauche +, gauche -) |
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Term
| What is required for optical activity about a sp3 hybridized carbon |
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Definition
| four different bond polarizabilities |
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Definition
| defines the sequence of spatial arrangements of asymmetrically substituted carbon atoms along a polymer chain. You must show more than one repeating unit to illustrate tacticity |
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Term
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Definition
| same spatial arrangement of equivalent asymmetrically substituted carbon atoms along a polymer chain. |
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Term
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Definition
| alternating spatial arrangement of equivalent asymmetrically substituted carbona toms along a polymer chain. |
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Term
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Definition
| random sequence of asymetrically substitued carbon atoms along a polymer chain |
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Term
| Which isomer of a polymer is capable of exhibiting optical activity? |
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Definition
| Only the syndiotactic isomer- though this may or may not exhibit optical activity depending on the R group etc. optical activity relies on the optical center having 4 different bond polarizabilities around it |
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| What conformational isomer of a polymer has the farthest end-to end distance? |
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Definition
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| What are some common helical arrangements of polymers |
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Definition
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Term
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Definition
| monomer present until the end of the reaction, high molecular weight chains formed at early stages of reaction. three basic steps: 1) initiation 2) propagation and 3) termination. Once a chain is initiated, it rapidly grows to a high molecular weight before a termination event occurs. |
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Term
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Definition
| monomer disappears at early stages of the reaction, high molecular weight chains only obtained when > 99% of reaction has occurred, mechanism involves the mutually independent reactions of functional groups at the ends of molecules |
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