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Opto‐mechanical properties of fibres. Part 2. Effect of stretching on some optical and structure parameters of PET fibres (woollen type)
Author(s) -
Fouda IM,
Shabana HM
Publication year - 1999
Publication title -
polymer international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.592
H-Index - 105
eISSN - 1097-0126
pISSN - 0959-8103
DOI - 10.1002/(sici)1097-0126(199903)48:3<189::aid-pi130>3.0.co;2-1
Subject(s) - refractive index , materials science , birefringence , optics , isotropy , amorphous solid , crystallinity , polarizability , orientation (vector space) , molecular physics , composite material , crystallography , geometry , molecule , chemistry , mathematics , physics , optoelectronics , organic chemistry
The influence of cold drawing on the birefringence, orientation,crystallinity and other structural parameters is examined forpolyester (Egyptian PET woollen type). A two‐beamPluta polarizing interference microscope connected to a device fordynamically studying the effect of the draw ratio on the refractiveindices has been used. The optical data obtained the densities andcrystallinities of the samples. The mean square density fluctuation〈η 2 〉, crystalline orientation function,amorphous orientation function, the number of chains per unit volume N c and the number of random links between thenetwork junction points N 1 are then calculated.Calculations are also carried out to determine the strain opticalcoefficient, the orientation factor, the orientations angle, thenumber of molecules per unit volume N , and the isotropicrefractive index. In addition, Poisson's ratio over all strainranges, the distribution of segment at an angle θ with respectto the draw ratio, the electric polarizability constant(Δα/3α 0 ) and otherstructural parameters and constants are calculated. An empiricalformula is suggested to correlate the change in Δ n , F c , F a , ω(cosθ), A and N c , and its constants aredetermined. The refractive index profile is studied. Interferogramsand curves are given for illustration. © 1999 Society of Chemical Industry