Specific Heat of Synthetic High Polymers. I. A Study of Polyethylene Including a Statistical Theory of Crystallite Length

1952 ◽  
Vol 20 (5) ◽  
pp. 781-790 ◽  
Author(s):  
Malcolm Dole ◽  
W. P. Hettinger ◽  
N. R. Larson ◽  
J. A. Wethington
Keyword(s):  
Statistical Theory ◽  
Specific Heat ◽  
High Polymers

Specific Heat of Synthetic High Polymers. IV. Polycaprolactam.

1955 ◽  
Vol 59 (10) ◽  
pp. 1015-1019 ◽  
Author(s):  
Paul Marx ◽  
C. W. Smith ◽  
A. E. Worthington ◽  
Malcolm Dole
Keyword(s):  
Specific Heat ◽  
High Polymers

scholarly journals Statistical theory of superlattices

1935 ◽  
Vol 150 (871) ◽  
pp. 552-575 ◽  
Keyword(s):  
Mathematical Method ◽  
Statistical Theory ◽  
Specific Heat ◽  
Low Temperatures ◽  
Lattice Points ◽  
The Other ◽  
Electric Resistance ◽  
Regular Lattice ◽  
Small Temperature ◽  
Average State

In a recent paper, Bragg and Williams have pointed out that the arrangement of the atoms in an alloy depends in a striking way on the temperature. At high temperatures, the atoms are distributed practically at random among the lattice points of the crystal, but at low temperatures a superlattice may be formed such that the atoms of one kind are arranged in a regular lattice of their own and the atoms of the other kind occupy the remaining “sites” in the crystal. The transition from the ordered to the disordered state occurs in a fairly small temperature range, and is accompanied by a large specific heat, an increase in electric resistance, etc. The mathematical method employed by Bragg and Williams is similar to that used in Weiss’s theory of ferromagnetism . Both involve the assumption that the “force” tending to produce order at a given point is uniquely determined by the average state of order throughout the crystal. Actually it will depend on the configuration of the atoms in the immediate neighbourhood of the point under consideration. The order of the crystal as a whole determines this configuration only on the average. In the present paper, the effect of fluctuations in configuration, which was neglected by Bragg and Williams, will be taken into account.

Specific heat of synthetic high polymers. VIII. Low pressure polyethylene

1957 ◽  
Vol 24 (106) ◽  
pp. 201-213 ◽  
Author(s):  
Bernhard Wunderlich ◽  
Malcolm Dole
Keyword(s):  
Specific Heat ◽  
Low Pressure ◽  
High Polymers

Pyridinium High Polymers—A New Class of Oil-Resistant Synthetic Rubbers

1957 ◽  
Vol 30 (1) ◽  
pp. 338-351
Author(s):  
W. B. Reynolds ◽  
J. E. Pritchard ◽  
M. H. Opheim ◽  
G. Kraus
Keyword(s):  
Zinc Oxide ◽  
Statistical Theory ◽  
Ternary System ◽  
Rubber Elasticity ◽  
New Class ◽  
Organic Halides ◽  
Low Levels ◽  
High Polymers

Abstract Copolymers of butadiene and 2-methyl-5-vinylpyridine are readily vulcanized by heating in the presence of organic halides. The number of effective crosslinks can be readily calculated from moduli of swollen stocks using the statistical theory of rubber elasticity. Crosslinking depends upon the amount and activity of the quaternizing agent. However, even at low levels of halide concentration, it appears that several quaternary groupings are necessary for each effective crosslink. Zinc oxide greatly increases the moduli of the swollen copolymer-halide systems. However, sulfur and accelerator alone have little effect on the same system and these agents do not further increase the moduli of the swollen ternary system, copoylmer-halide-zinc oxide.

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