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Unformatted text preview: cules oftenreheated.
ure 2.9–2a shows that the
direct dissolution mechanism A degr
tence of thisbackbone and various side groups. These
bonded double bond withinlinemacromolecule permits the diagram in a
tie line Horizontal (Figureframework phase formation of additional
drawn onThe on which atoms are
a primary bonds between rubber
mechanism in which the solid dissolves d
primary bonds between chains The 2.9–2b).
macromolecules connecting the compositionare knowntwo
can of heated to form a bonds of the as
two-phaseby the openingbe thethree-dimensional structures. crosslinks.
ﬁeld periodic unsaturated double melt repeatedly.
surrounding liquid without substantial ch
When the crosslink density is low, only a small fraction of the double bonds have been
thermosetequilibrium.A polymer (usually composed of a
phases crystalline Having atoms or ions arranged on a
dislocation A linear defect in a crysta
opened, and the individual polymer chains retain their identity. There are only a “few”
three-dimensional network of covalently bonded atoms)
primary bonds between chains. As the crosslink density increases, the order. chains
tilt boundary A boundary composed of edge
responsible for plastic deformation.
three-dimensional lattice having long-range
that does not melt structure begins to
lose their identity and the when reheated.resemble a three-dimensional network of
dislocations of the same sign stacked vertically above one
primary bonds. This 3-D primary bond structure is characteristic of many polymers that
tie line Horizontal line drawn on a phase diagram in a
do not form aAs a or thermoset all of the extra half planes being
another. melt, result of polymers.
two-phase ﬁeld connecting the composition of the two
in one portion of the crystal, a tilt is created.
phases in equilibrium.
time-dependent AC boundary composed of CedgeC that occurs
tilt boundaryC C deforma...
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