Page 136 - Carrahers_Polymer_Chemistry,_Eighth_Edition

Polycondensation Polymers 99

TABLE 4.2
Properties and Uses of Some Important Synthetic Condensation-Type Polymers
Type (Common
Name) Typical Properties Typical Uses
Polyamides Good balance of properties; high strength, good Fibers—about ½ of all nylon fiber goes into

(nylons) elasticity and abrasion resistance, good toughness tire cord; rope, cord, belting, fi ber cloths,
favorable solvent resistance, outdoor weathering, thread, hose, undergarments, dresses;
moisture resistance plastics—used as an engineering material,
substitute for metal bearings, bearings, cams,
gears, rollers, jackets on electrical wire
Polyurethanes Elastomers—good abrasion resistance, hardness, Four major forms used—fi bers, elastomers,
resistance to grease, elasticity; fi bers—high coatings, foams; elastomers—industrial
elasticity, excellent rebound; coatings—good wheels, heel lifts; fi bers—swimsuits,
resistance to solvents and abrasion; good fl exibility, foundation garments; coatings—fl oors where
impact resistance; foams—good strength per impact and abrasion resistance are required,
weight, good rebound, high impact strength bowling pins; foams—pillows, cushions
Polyureas High T g , fair resistance to greases, oils, solvents Not widely used
Polyesters High T g and T m ; good mechanical properties, Fibers—garments, permanent press and “wash
resistance to solvents and chemicals; good & wear” garments, felts, tire cord, fi lm—
rebound low moisture absorption, high modulus; magnetic recording tape, high-grade fi lm
film—high tensile strength (about that of steel),

stiff, high resistance to failure on repeated fl exing,
high impact strength, fair tear strength
Polyethers Good thermoplastic behavior, water solubility; Sizing for cotton and synthetic fi bers;
moderate strength and stiffness stabilizers for adhesives, binders, and fi lm
formers in pharmaceuticals; thickeners;
production of fi lms
Polycarbonates Crystalline with good mechanical properties, high Machinery and business
impact strength; good thermal and oxidative
stability, transparent, self-extinguishing, low
moisture absorption
Phenol- Good heat resistance, dimensional stability, Used in molding applications; appliances, TVs,
formaldehyde resistance to cold flow, solvent, dielectric automotive parts, filler, impregnating paper,

resins properties varnishes, decorative laminates, electrical parts,
countertops, toilet seats; adhesive for plywood,
sandpaper, brake linings, abrasive wheels
Polyanhydrides Intermediate physical properties; medium to poor No large industrial applications
T g and T m
Polysulfides Outstanding oil and solvent resistance; good gas Gasoline hoses, tanks, gaskets, diaphragms

impermeability, resistance to aging, ozone, bad
odors, low tensile strength, poor heat resistance
Polysiloxanes Available in a wide range of physical states—from Fluids—cooling and dielectric fluids, in waxes &

liquids to greases, to waxes, to resins, to polishes; as antifoam and mold release, for
elastomers; excellent high and moderate low paper and textile treatment: elastomers—
temperature physical properties; resistant to gaskets, seals, cable, wire insulation, hot liquids
weathering and lubricating oils and gas movement, surgical and prosthetic
devices, sealing compounds; resins-varnishes,
paints, encapsulating, and impregnating agents

Polyphosphate Good fire resistance, fair adhesion, moderate Additives promoting fl ame retardance;
and poly- moisture stability, fair temperature stability adhesive for glass (since it has a similar
phosphonate refractive index), pharmaceuticals, surfactant
esters

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