有机聚合物化学英文

Polys tyre ne
S tyre n e
Poly(vi n yl ch l ori de ) (PVC )
To
name a polymer, prefix poly to the name of the monomer from which it is derived.
• For more complex monomers or where the name of the monomer is two words, enclose the name of the monomer in parens, for example poly(vinyl chloride). 29-4
Nylon 66, source of Hexanedioic Acid
• The raw material base for the production of nylon 66 is benzene, which is derived from cracking and reforming of petroleum.
3 H2 catalys t Be n z en e O2 catalys t
Cycl oh e xan e OH + O
HN O 3
COOH COOH
Cycl oh e xan ol
Cycl oh e xan on e
He xan edi oic acid (Adi pic acid)
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Nylon 66, source of the 1,6 hexanediamine
As
the degree of crystallinity increases, the polymer becomes more opaque due to scattering of light by the crystalline regions. Melt transition temperature, Tm: The temperature at which crystalline regions melt.

Polyamides Nylon 66
Nylon
HO
66 (from two six-carbon monomers).
O OH + H2N N H2 h e at
O He xan edi oic acid (Adi pic acid)
1,6-He xan e diami n e (He xam eth yle n e diami n e ) O O N H Nylon 66 H N
• As the degree of crystallinity increases, Tm increases.
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Morphology: Amorphous
Highly
amorphous polymers are sometimes referred to as glassy polymers.
• ordered crystalline domains • disordered amorphous domains
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Morphology: Crysatline
High
degrees of crystallinity are found in polymers with
• regular, compact structures • strong intermolecular forces, such as hydrogen bonds and dipolar interactions.
Glass
transition temperature, Tg: The temperature at which a polymer undergoes a transition from a hard glass to a rubbery solid. Put polystyrene cup in boiling water.
Monomer:
From the Greek, mono + meros, single
part.
• The simplest nonredundant unit from which a polymer is synthesized.
Plastic:
A polymer that can be molded when hot and retains its shape when cooled.
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Morphology
Completely
amorphous PET is formed by quickly cooling the melt.
• PET with a low degree of crystallinity is used for plastic beverage bottles.
Chain Mass, MiNi
12g 28 14 48 64 36 20
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Example
Now for weight averaged MW
Chain MW, Mi
120 140 140 160 160 180 200
Moles Present, Ni
0.10 0.20 0.10 0.30 0.40 0.20 0.10
n
• During fabrication, nylon fibers are cold-drawn to about 4 times their original length, which increases alignment, crystallinity, tensile strength, and 29-15 stiffness.
• weight average MW:
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Example
Sample has the unique chains
Chain MW, Mi
120 140 140 160 160 180 200
Moles Present, Ni
0.10 0.20 0.10 0.30 0.40 0.20 0.10
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Morphology
• Example: poly(ethylene terephthalate), abbreviated PET or PETE, can be made with crystalline domains of 0% to 55%.
O O O O
n Poly(e thyle ne te re phthal ate )
ab
Molecular Weight
All
polymers are mixtures of individual polymer molecules of variable MWs.
• number average MW: Count the number of chains of a particular MW (Ni moles), multiply each number by the MW (Mi), sum these values, and divide by the total number of polymer chains.
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Continued
Thermoplastic:
A polymer that can be melted and molded into a shape that is retained when it is cooled. Thermoset plastic: A polymer that can be molded when it is first prepared but, once it is cooled, hardens irreversibly and cannot be remelted.
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Step-Growth Polymers

Step-growth polymerization: A polymerization in which chain growth occurs in a stepwise manner between difunctional monomers. Many chains initiated at same time. All monomeric -> mostly dimeric -> mostly trimers. Etc. five types of step-growth polymers: • Polyamides • Polyesters • Polycarbonates • Polyurethanes • epoxy resins 29-14
More
crystallline formed by slow cooling, more molecular diffusion occurs and crystalline domains form as the chains become more ordered.
• PET with a high degree of crystallinity can be drawn into textile fibers and tire cords.
• Lacking crystalline domains that scatter light, amorphous polymers are transparent. • They are weaker polymers, both in terms of their greater flexibility and smaller mechanical strength. • On heating, amorphous polymers are transformed from a hard glassy state to a soft, flexible, rubbery state.