Polar and nonpolar plastic
the so-called electronegativity, in simple terms, is the power of of electrons in the atoms attract a covalent bond. The more electronic elements around the nucleus, the larger the electronegativity. Obviously, the greater the electronegativity difference between the two elements, the polarity of the two elements in combination with the more powerful. The polarity of the polarity of molecules or key size, usually by dipole moment. Each chemical bonding fixed dipole moment, referred to as a key moment, the key moment vector and is molecular dipole moment.
a chain, a single bond on the bonded atoms or replace with other atoms groups, when they are due to rotation in approaching in the distance, total want to interfere with each other and rejection, especially the properties of substituents effects. Moreover, a main chain does not necessarily completely by more supple C - Or C - C key O key, which may be keyed has other structural components, such as groups, more rigid rings is relatively reduced, rotating a single bond proportion within the molecule chain rotation bound. Therefore, the size of the molecular chain flexibility is conditioned by many structural factors. Article
symmetric structure of large molecules, all dipole moment can offset each other, present a neutral, ptfe are nonpolar plastic it is for this reason. The structure characteristics of the polar molecules is asymmetry. In terms of the dipole moment of the polymer, is not only associated with the dipole moment of molecule, and state of aggregation of molecules and the intermolecular forces. The size of the polymer polarity, not only can be used to determine material rigidity, heat resistance and electric properties, and in the solvent resistance and permeability resistance assessment of the materials was also has guiding significance. Associated with the many other properties, such as printing, adhesive, surface wettability can be made of polymer materials, such as the polarity of judgement.
in the polymer chain contains many single bond, bond compared with double bond, three key, in addition to the weak bonding energy, there is also a characteristic is that the two atoms can be linked to a single bond relatively around the bond axis at a certain Angle of rotation keys without changing the distribution of the electron cloud of atoms in space position and configuration mode will be changing due to a single bond in turn. Within a single bond rotation this feature, it is under a certain temperature exhibited a unique way of molecular motion.
in the covalent bond, if the electron pair is not an average of two atoms have in common, but the partial belongs to one of these atomic time, becomes a polar bond. Injection tooling in fact many covalent bond is polar, that is, one end of the key with a small amount of negative charge, while the other end slightly positively charged. Polar bond because of its electronic to varying degrees of deviation, and with different degrees of polarity. The strength and direction of polar bond polarity, depends on the bond of each of the two atoms of electronegativity.
macromolecular chain has the ability of curl and changing its shape. This feature is called the flexibility of polymer chain or flexibility. Obviously, the flexible long chain from the chain of macromolecular chain structure and internal rotation characteristics of a single bond. For a specific molecules, the longer the chain, rotate the easier, in its molecular chain is more smooth. However, a single bond is not subject to resistance, completely free in rotation is virtually impossible.
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