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Abstract

Anisotropic dimensional changes in uniaxially oriented acrylonitrile copolymer film during coagulation were investigated isothermally by varying the NaSCN concentration. Anisotropic dimensional change occurs when the swollen acrylonitrile films are im mersed in a strong nonsolvent (e.g., 35% NaSCN) or the degree of orientation prior to cross-linking at an adequate level, and swelling is high enough. The former phe nomenon is due to skin (semipermeable membrane) formation and nonuniform coagula tion; the latter phenomenon is due to spontaneous elongation, and the wide-angle x-ray diffraction measurements show that it occurs with crystal-liquid transformation in accordance with the previously reported theory that reversible contractile processes are related to these transformations.

Keywords

Aclrylonitrile acrylamide reactants. Acrylonitrile copolymers copolymers films. Textile materials. Redox catalyst catalyst DMF solvent NaSCN solution aqueous solution. Temperature time concentration pH. Cross-linking coagulation de- swelling dimensional changes melting crystallization chain deformation x-ray dif fraction elongation contraction dimensional stability coagulation. Acrylonitrile copolymer film x-ray diffraction measurement. Suspension polymerization cross- linking swelling coagulation.

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References

Flory, P.J. , Theory of Elastic Mechanisms in Fibrous Proteins. J. Am, Chem. Soc. 78, 5222-5235 (1956).

Flory, P.J. and Garrett, R.R. , Phase Transitions in Collagen and Gelatin Systems, J. Am. Chem. Soc. 80, 4836-4845 (1958).

Flory, P.J. and Spurr, O.K. , Melting Equilibrium for Collagen Fibers under Stress. Elasticity in. the Amorphous State, J. Am. Chem. Soc. 83, 1308-1316 (1961 ).

Mandelkern, L. , The Crystallization of Flexible Polymer Molecules , Chem. Rev. 56, 903-958 (1956).

Mandelkern, L. , "Crystallization of Polymers," Mc-Graw-Hill, New York, 1954, Chapter 7.

Mandelkern, L. , Halpin, J.C. , Diorio, A.F. , and Posner, A.S. , Dimensional Changes in Fibrous Macromolecules: The System α-Keratin-Lithium Bromide, J. Am. Chem. Soc. 84, 1383-1391 (1962).

Mandelkern, L. , Meyer, W.T. , and Dioro, A.F. , Effect of Monomeric Reagents on the Melting (Contraction) and Recrystallization of Fibrous Proteins, J. Phys. Chem. 66, 375-376 (1962).

Mandelkern, L. , Posner, A.S. , Diorio; A.F. , and Laki, K. , Mechanism of Contraction in the Muscle Fiber Adenosinetriphosphate (ATP) System, Proc. Natl. Acad. Sci. (U.S.) 45, 814-819 (1959).

Mandelkern, L. , Roberts, D.E. , Diorio, A.F. , and Posner, A.S. , Dimensional Changes in Systems of Fibrous Molromolecules: Polyethylene, J. AM, Chem. Soc. 81, 4145-4157 (1959).

10.

Roberts, D.E. , Mandelkern, L. , and Flory, P.J. , The Isotropic' Length of Polymer Networks , J. Am. Chem. Soc. 79, 1515 (1957). Communication.

11.

Oth, J.F.M. and Flory, P.J. , Thermodynamics of Shrinkage of Fibrous (Racked) Rubber, J. Am. Chem. Soc. 80, 1297-1304 (1958).

Dimensional Changes of Acrylonitrile Copolymer During Coagulation

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