Second-Order Transition Temperatures and Related Properties of Polystyrene. I. Influence of Molecular Weight

Journal of Applied Physics - Tập 21 Số 6 - Trang 581-591 - 1950
Thomas Fox1, Paul J. Flory1
1Department of Chemistry, Cornell University, Ithaca, New York

Tóm tắt

Dilatometric and viscometric data on fractionated polystyrenes containing diethylbenzene end groups are presented over wide temperature ranges. The second-order transition temperature, viscosity-temperature coefficient, and specific volume all change rapidly with increasing molecular weight toward asymptotic limits which are practically reached at M≅30,000. Empirical expressions are presented relating these properties to molecular weight and temperature. In each case the dependence on molecular weight is expressed as a simple function of M̄n−1. These observations are interpreted and correlated on the basis of the hypothesis that the local configurational order in a liquid polymer is disturbed by the introduction of end groups to a degree that is proportional to their number. The second-order transition does not represent an isoviscous state. The internal local configurational structure appears to be equivalent, and independent of temperature, in all polystyrenes below their second-order transition temperatures.

Từ khóa


Tài liệu tham khảo

1948, Chem. Rev., 43, 219, 10.1021/cr60135a002

1940, J. Am. Chem. Soc., 62, 1057, 10.1021/ja01862a020

1948, J. Am. Chem. Soc., 70, 2384, 10.1021/ja01187a021

1938, Zeits. f. Physik. Chemie, A182, 361

1940, Zeits. f. Physik. Chemie, B45, 25

1948, J. Polymer Sci., 3, 647, 10.1002/pol.1948.120030506

1949, J. Research Nat. Bur. Stand., 43, 145, 10.6028/jres.043.017

1943, J. Am. Chem. Soc., 65, 543, 10.1021/ja01244a013

1946, J. App. Phys., 17, 398, 10.1063/1.1707730

1937, Trans. Faraday Soc., 33, 27, 10.1039/tf9373300027

1936, J. Chem. Phys., 4, 283, 10.1063/1.1749836

1943, J. App. Phys., 14, 700, 10.1063/1.1714949

1913, Zeits. f. Physik. Chemie, 84, 643

1923, Trans. Faraday Soc., 19, 6, 10.1039/tf9231900006

1925, Trans. Faraday Soc., 21, 151, 10.1039/tf9252100151

1937, Physica, 4, 1073, 10.1016/S0031-8914(37)80204-9

1939, 6, 129

1933, J. Am. Ceram. Soc., 16, 619, 10.1111/j.1151-2916.1933.tb16942.x

1947, J. Soc. Glass. Tech., 31, 74

1936, J. Chem. Phys., 4, 70, 10.1063/1.1749750

1942, Ind. Eng. Chem., 34, 1052, 10.1021/ie50393a008