Unformatted text preview: d that size such that either
the only type
criticaland composition. of the can form between PE chains is the
interface accomplished by solid-state diff
growth or dissolution will decrease its free energy.
conditions of high temperature and press
thermoplastic polymer A polymer composed of
energy of critical resolvedformationstress (polymer chain from a collection of
the system. Thus, the shear of a PE
diffusion coefﬁcient The constant in t
long-chain molecules often composedCRSS) covalently stress
of a The shear
identical monomers is in the slip planefavored reaction. Note that inat which the
resolved a thermodynamically side groups. These contrast to
in the slip direction
relating mass ﬂux per unit area to the co
bonded backbone and various
monomer, the PE polymer chain is saturated, so there are no additional sites for primary
plastic deformation occurs. remains for bond formation between PE
gradient. It obeys an Arrhenius-type equ
bond formation. Thus, the onlybe heated to form a melt repeatedly.
macromolecules system variables such as pressure,
and is secondary bondcan mechanism that
the external formation. Linear polymers that form melts upon heating, such
such is strongly temperature-dependent.
crosslinks Primary bonds formed between adjacent
thermoset polymer polymers.
astemperature, and composition.
PE, are called thermoplastic A polymer (usually composed of a
coefﬁcient describes the ease of atomic o
polymer chains. These atomic “bridges” are often
The structure of
three-dimensional network of covalently oxygen or sulfur but
thermoplastic rubber is fundamentally ofhydrocarbon that of the thermoplastic
polymer of the polymer composed of structure in FigA generic either bonded atoms)
the solid state.
polymers. composed of small chains
that does not composed of composed of small groupsbond.atoms.
when many other a covalently
long-chain be meltpolymer chains contain an unsaturated double of The exismole...
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