the thing

___ Factors in a polymer can affect its __ behavior.

chemical, thermal

Semiconductors have conductivities of about ___ to ___/(ohm.m)

1E-4, 1E-6

The Wright Flyer crankcase was made of ___ with ___ and ___ alloying elements.

Al, Cu, Fe

Common polymers typically have ___ strength, ___ that of materials and ceramics.

low, <10%

Polymers typically have ___ bonds between the polymer-chains.

Van der Waals

Semiconductors can be ___ or ___ semiconductors.

intrinsic, extrinsic

Polyethylene has a sidegroup of hydrogen. Polypropylene has a sidegroup of CH3. As a result, polypropylene has a Tg that is ___ compared to that of polyethylene.

lower — LAST YR IT WAS MARKED WRONG BUT THE BOOK SAYS ITS RIGHT

Cross-polarized light reveals a ___ in each spherulite.

Maltese cross

A lightly cross-linked polymer is typically ___ a semi-crystalline polymer.

less stiff than

Kevlar fibers are made by a process of ___

wet spinning

Addition polymers include ___, ___, and ___.

vinyls, vinylidene, dienes

The process of blown-film extrusion begins with ___ of a plastic ___ that is drawn upward while still ___, and simultaneously ___ by ___ inflated into it through a ___.

extrusion, tube, molten, expanded, air, die

We can use phase diagrams and ___ graphs to predict the effects of ___ and ___ on the strength of age-hardened alloys.

strength vs. time, temperature, time

Semicrystalline polymers form ___ as they cool down from the melt.

spherulites.

Age hardened alloys can be used for bicycle ___, ___ cookware, and ___ in integrated circuit chips.

frames, metal, metal interconnects

Aging an alloy at ___ is called natural ageing.

room temperature

During precipitation hardening of Al-Cu, the hardness of the alloy ___ as the precipitates ___ beyond the ___.

decreases a bit, coarsens, optimum size

The resistance of a resistor can be calculated by the expression, R= ___, where rho is the resistivity of the material, R is the resistance, A is the cross-sectional area, and L is the length of the resistor.

rho*L/A —> none of these

During artificial ageing, ___ form ___ room temperature, but below the ___ temperature, to provide ___ strengthening

precipitates, above, solvus, precipitate

Examples of thermoplastics include ___, ___, and ___.

polyethylene, polypropylene, polystyrene

The four different types of polymer structures are ___, ___, ___, and ___.

amorphous 1-D chains, semicrystalline 1-D chains, thermoset 3-D networks, elastomer 3-D networks

In a four-roll calendar process, a was od ___ is passed through a series of ___ to ___ the thickness of the plastic to the desired ___.

plastic, rolls, reduce, gage

In the band-structure model for conductivity, the topmost band of the atoms that is filled with electrons is the ___ band.

valence

As the strain-rate (that a polymer is subjected to) increases, the glass-transition temperature ___.

increases

Phase diagrams and ___ vs ___ graphs can be used to predict the optimum ___ and ___ for the strongest age-hardened alloys.

strength, anneal-time, temperature, time

There are ___ major synthesis methods for making polymers.

none of these

Examples of amorphous polymers are ___, ___, and ___.

polystyrene, polymethylmethacrylate, polycarbonate

The glass transition temperature of Bakelite is ___ degrees C

180

Amorphous polymers are ___ and have ___ or ___ oriented chains.

glassy, unoriented, randomly

An Al-Cu alloy with a small wt% Cu, develops theta-double-prime phase regions when it is heat-treated. This phase is ___ and ___ with the alpha-phase lattice.

disordered, coherent

In the band-structure model for conductivity, there are ___ configurations for the conduction and valence bands in a given material.

4

Engineering structural polymers can be ___ or ___.

reinforced, unreinforced

Polymer molecules are typically ___ to ___ atoms long.

100s, 1000s of

In the band-structure representation of a semiconductor, at the ____ interatomic ____, there is a small ___ band gap.

equilibrium, spacing, energy

One-D linear chain polymers can be ___ or ___.

amorphous, semi-crystalline

In the leathery region of the log-modulus vs temperature curve of a polymer, the polymer is usually ___ and ___.

less stiff, has some ductility with less strength

Lithium has ___ electrons in its first shell, and ___ electron in its outermost shell, which is the ___ shell.

2, 1, second

During solution treatment, an alloy is heated ___ the ___ temperature to dissolve ___ to form a ___ single-phase structure.

above, solvus, second-phase particles, homogeneous

In a semiconductor, for an electron to conduct, it must acquire enough ___ for it to cross the forbidden energy-gap between the ___ and ___ bands.

energy, valence, conduction

Reaction injection molding is used for manufacture of ___.

car bumpers

Martensite is caused by a change in ___, not by ___ of carbon.

crystal structure, diffusion

The amount of ___ in a polymer can modify its ___ and ___ properties.

plasticizer, thermal, mechanical

In metals, ___ electrons contribute to electrical conduction.

delocalized valence

There are ___ major morphologies among polymers.

4

An elastomer customer-product is created by adding in a ___ to the elastomer, ___ ___ and then ___ the eslatomer.

crosslink agent, mixing, shaping, reacting

The four major structural categories of polymers are ___, ___, ___, and ___.

amorphous thermoplastics, semicrystalline thermoplastics, elastomers, thermosets

The Recycling category 1 (a recycle triangle with a 1 inside it) applies to ___ or ___ polymers.

PET, PETE

Addition polymers are also ___ polymers.

free radical

During injection blow molding, a parison is ___ around a ___. The ___ is then opened and the parison is transferred to a ___ mold. The ___ is inflated to conform to the ___. The mold is then opened and the ___ is removed.

injection-molded, blowing rod, injection-mold, blow, soft polymer, blow mold, blown product

Semi-crystalline polymers are ___ and ___ between Tg and Tm.

ductile, tough