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The length of the chain segment can be represented by the number of chain links. The shorter the chain segment, the more units on the main chain that can move independently, the greater the flexibility of the chain, and the greater the rigidity.
22.Milling properties of wool
Under wet and hot conditions, the fibers of wool are interspersed and entangled with each other under the repeated action of external force, and the fiber aggregates gradually shrink tightly.
Fiber obtained by extracting cellulose from bamboo.
The reaction of synthesizing polymers with low molecular weight monomers is called polymerization.
The geometric arrangement and classification of the atoms in the molecule formed by the rotation of the single bond is called conformation.
It refers to the polymerization in which the monomer dissolved with the initiator is suspended in water in the form of small droplets.
The cellulose that has been hydrolyzed to a certain extent by the action of acid is called hydrolyzed fiber.
It is a linear macromolecule composed of β-D-glucose residues connected by β-1,4 glycosidic bonds.
At a certain temperature, the polymer sample is rapidly deformed, and an internal stress that competes with the external force is generated in the sample. Under the condition of keeping the deformation unchanged, the stress continues to decay with time.
There are only monomers and a small amount of catalyst in the system, and the polycondensation reaction is carried out above the fusion point of the monomer and the polymer.
31. cohesive energy
Cohesive energy refers to the total energy of 1 mol of molecules together, which is also equal to the total energy of separation of the same number of molecules.
Straightness is the ratio of natural length to straightened length.
is the slope of the stress-strain curve, generally the initial modulus is the stress-strain ratio of one percent of the fiber elongation.
In the process of spinning and forming synthetic fibers, fibers or hollow fibers with non-circular cross-sections spun with special-shaped spinnerets are called special-shaped fibers.
The polymer chains with a certain conformation are assembled into a certain regular arrangement through the action of hydrogen bonds and van der Waals forces.
It refers to the phenomenon that the deformation of the polymer gradually increases with the increase of time under the action of a certain temperature and a small constant external force.
The basic structural unit that constitutes a macromolecular chain is called a structural unit or a repeating unit. Since the repeating unit is the basic unit that constitutes the macromolecular chain, it is also called a chain link.
38.Directional friction effect
When unsaturated and ethylene monomers and cyclic compounds generate high polymers through their own addition polymerization reaction, the difference in friction coefficient along the direction of the scales is called the directional friction effect when the reactive fibers move.
Treat cotton fabric with concentrated caustic soda solution (18%-24%) at room temperature, and then wash off the lye solution on the fabric under the condition of applying tension to the fabric, thereby improving the properties of cotton fiber.