Changes in Molecular Size and Size Distribution and Their Effects on Mechanical Properties of Nylon-6 Yarns During Texturizing

Abstract

The changes in average intrinsic viscosity and its distribution and their effect on mechanical properties of nylon-6 (poly caprolactam) multifilament yarn during texturizing were studied. It was found that change in average intrinsic viscosity is not the only indicator of the changes taking place in the, mechanical properties of the yarn. The changes in the molecular size distribution, on the other hand, can be regarded as a better indicator in this regard. The reduction in the breaking stress of the textured yarn is dependent on texturizing variables— e.g. : heater temperature, contact time twist, inherent moisture content of the feed yarn, yarn tension in the texturizing zone, etc. The elongation percentage at break, on the other hand, may either decrease or increase. The changes have been found to be dependent on the changes in the low molecular weight, high molecular weight species and broadness of the distribution curve.

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References

Artunc, H. , Changes in the Structure of Polyamide Filament Yarns During False-Twist Texturizing—Contactless Temperature Measurements on Running Yarns, Textile Praris International 30, 1392 (1975).

Becht, J. , and Fischer, H. , Electron Spin Resonance, DTA and Molecular Weight Studies on Mechanically Stressed Synthetic Filaments, Kolloid, Z.Z. Polym. 210, 766 774 (1970).

Bhattacharya, T.K. , Abuhakkar, Md. , and Mukherjee, A.K. , Effects of Anti-Oxidants on Size Distribution of Poly-caprolactam During Melting and Melt spinning, Textile Res. J. 47, 132 139 ( 1977).

Flory, P.J. , Polymerization of Unsaturated Monomers IV Free-Radical Mechanisms , in "Principles of Polymer Chemistry," Cornell University Press, New York, 1953, Chapter IV, p. 106.

Juilfs, Von J. , Zur Fraktionieren Fallung Von Polyamidon, Kolloid, Z.Z. 141, 88 94 ( 1955).

Kato, K. , Furukawa, K. , and Yoshizaki, O. , Mechanical Scisson of Nylon-6 Molecules during Drawing Process. I. The Effects of the Ways of Loading and Drawing on Scission, Kobunshi Kagaku 28, 687-692 (1971).

Kato, K. , Furukawa, K. , and Yoshizaki, O. , Mechanical Scission of Nylon-6 Molecules during Drawing Process. II. Change of Molecular Weight and Molecular Weight Distri bution and Discussions on the Mechanism of the Scission, Kobunshi Kagaku 28, 693 700 (1971).

Kausch, H.H. , Thermomechanical Dissociation of Nylon-6 (Perlon), Kolloid, Z.Z. Polym. 247, 768 773 (1971).

Kotera, A. , in "Polymer Fractionation" Ed. Cantow, M. J. R. , Academic Press, New York (1967), p. 47.

10.

Levantovskaya, I.I. , Kovarskaya, B.M. , Drayluk , G.V. , and Neiman, M.B. , Mechanism of the Thermo-Ovidative Degradation of Polyamides, Vysokomol. Soedin. 6, 1885 (1964).

11.

Lishnevski, V.A. , Investigations of the Cold drawing of Polymers by an Electronic Paramagnetic Resonance Method, Vysokomol. Soedin. B11, 44-49 (1969).

12.

Mark, H. , and Raff, R. , "High Polymeric Reactions," Interscience, New York, 1941.

13.

Mikhailov, N.V. , Tokareva, L.G. , and Kovaleva , M.V. , "Mechanism of Ageing of Synthetic Fibers. I. Investigation of Thermal and Thermo-Ovidation Effects on Polyamides and their Fibers, Vysokomol. Soedin 2, 581 (1960).

14.

Peterlin, A. , Bond

Rupture in Highly Oriented Crystalline

Polymers, J. Polym. Sci., Pt. A-2, 7, 1151 1163 (1969).

15.

Sengupta, A.K. , Singh, R.K. , and Majumdar , A. , Effect of Drawing and Texturizing on the Molecular-Weight Distribu tion of Nylon 6 Multifilament Yarns, Textile Res. J. 44, 155 163 (1974).

16.

Smith, S. , Reëquilibration of Polycaproamide, J. Polym. Sci. 30, 459 (1958).

17.

Soborolli, W. and Capacciolli , T. , Poly caproamide, Oxidation. II. Oxidation Degradation and Cross Linking, Cliu.c.Ind. (Milan) 42, 1325 (1960).

18.

Tobolsky, A.V. and Mark, H.F. , in "Polymer Science and Materials ," Wiley-Interscience, New York , 1971 , p. 37.

19.

Volokhina, A.V. , Kudryavtsev, G.I. , Skuratov , S.M. , and Nonetskaya , A.K. , The Polymerization Process in the Solid State, J. Polym. Sci. 53, 289 294 (1961).

20.

Wilkinson, G. D. , (Ed.) " Textured Yarn Technology I," Monsanto Textiles, Decatur, Ala. 1967, p. 66.