Dynamic mechanical studies of α and β relaxations of polyethylenes
Tóm tắt
The α and β relaxations of a variety of polyethylenes have been extensively studied using lowfrequency dynamic mechanical methods. The main focus of this work has been both the control and the quantitative measurement of the key structural factors that describe semicrystalline polymer systems. The structural factors that have been examined in detail include the level of crystallinity, the crystallite thickness, the interfacial content, and the supermolecular structure. Consequently a variety of other types of supplementary measurements were made to accomplish the necessary characterization. The location of the α transition is found to depend primarily on the crystallite thickness. There also is the distinct possibility that the interfacial structure exerts an important influence. The level of crystallinity and the supermolecular structure do not play a significant role in the location of
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Tài liệu tham khảo
McCrum N. G., 1967, Anelastic and Dielectric Effects in Polymer Solids
Meier D. J., 1978, Molecular Basis of Transitions and Relaxations
Perena J. M., 1972, An. Fis., 68, 207
Iwayanagi S., 1963, Rep. Prog. Polym. Phys. Jpn., 6, 179
1964, Rep. Prog. Polym. Phys. Jpn., 7, 269
Kakizaki M., 1965, Rep. Prog. Polym. Phys. Jpn., 8, 289
Meakins R. J., 1961, Progress in Dielectrics, 153
Nielsen L. E., 1962, Mechanical Properties of Polymers and Composites, 162
Takayanagi M., 1978, Molecular Basis of Transition and Relaxations
Baldi L., 1965, Mater. Plast. Elastomeri., 31, 1309
R.Allen M. S. Thesis Florida State University 1980.
Stein R. S., 1964, New Methods of Polymer Characterization
Glotin M., J. Polym. Sci. Polym. Phys. Ed.
J. Polym. Sci. Polym. Lett. Ed.
Glotin M., J. Polym. Sci. Polym. Phys. Ed.
G.Stack private communication.
G.StackandL.Mandelkern unpublished
Frohlich H., 1958, Theory of Dielectrics
McCrum N. G., 1978, Molecular Basis of Transitions and Relaxation
A.Dekmezian B.Borah andL.Mandelkern unpublished.
Popli R., 1982, Polym. Prepr. Am. Chem. Soc. Div. Polym. Chem., 23, 132