The effect of annealing on the mechanism of plastic deformation of oriented polypropylene

Yefimov, A.V.; Lapshin, V. P.; Fartunin, V.I.; Козлов, П.В.; Bakeyev, N.F.

doi:10.1016/0032-3950(83)90253-8

Cited by 9 publications

(1 citation statement)

References 13 publications

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“…Flexible-chain polyolefins such as high density polyethylene 1,2 and polypropylene [3][4][5][6] are capable to form the oriented lamellar structures during crystallization of polymer melts under extension. The thermal treatment of these samples at temperatures close to the melting temperature of a polymer leads to an increase in the degree of crystallinity and a decrease in the number of tie chains in amorphous regions between lamellae, and, finally, almost all tie chains become stressed.…”

Section: Introductionmentioning

confidence: 99%

Ordering Effects and Percolation in the Structure Formation Process of the Oriented Polyolefin Porous Films

Elyashevich

Novikov

Kuryndin

et al. 2017

ACSi

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Structure transitions and mechanism of the formation of superlattices lamellae in microporous polyolefin (polyethylene and polypropylene) films obtained in the process based on polymer melt extrusion followed by annealing, uniaxial extension and thermal fixation have been studied by statistical analysis of electron microscopy images of the film surface. The structure of the porous films prepared in the multistage process has been studied by SEM, gravimetry and permeability measurements. It has been shown that the pore formation at the stage of uniaxial extension is accompanied by the ordering of lamellae and their self-organization controlled by spin draw ratio and annealing temperature. It was established that an increase of these parameters lead to the transition of disorder-order type. The effect of preparation conditions on the ordering process of regular spatial lattices of lamellae has been discussed.

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Section: Introductionmentioning

confidence: 99%

Ordering Effects and Percolation in the Structure Formation Process of the Oriented Polyolefin Porous Films

Elyashevich

Novikov

Kuryndin

et al. 2017

ACSi

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Optomechanical variations in cold‐drawn thermally treated polypropylene fibers

Fouda

El‐Sharkawy

2003

J of Applied Polymer Sci

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A two-beam polarizing interference microscope with a microstrain device was used for measuring some optical and mechanical parameters for polypropylene (PP) fibers at room temperature (28 Ϯ 1°C). The changes in the molecular orientation were evaluated to obtain orientation factors f 2 (), f 4 (), f 6 (), ͗P 2 (cos )͘, ͗P 4 (cos )͘, and crystalline and amorphous orientation functions F c and F a , respectively. The shrinkage factor, uniaxial tension, true stress, molar refractivity R, surface reflectivity RЈ, the crosslink density N s , the chain entanglement density N c , the segment anisotropy ␥ s , and the number of chains NЈ were calculated. In addition, the shrinkage stress was found to increase with the increase of draw ratio. The dielectric constant , the dielectric susceptibility , the average work per chain wЈ, and the constants of the stress-birefringence equation were obtained. Comparison between Hermans's optical orientation functions and the corrected formulas by de Vries are given. The values of fully oriented refractive indices n 1 and n 2 were found. The generalized Lorentz-Lorenz equation given by de Vries was used to determine the structural parameters of PP fibers. An empirical formula was suggested to correlate the changes in the evaluated parameters with different draw ratios, and its constants were determined. The study demonstrated changes on the molecular orientation factors and evaluated microstructural parameters as a result of an applied cold-drawing process. Relationships between the calculated parameters and the draw ratios, together with microinterferograms were presented for illustration.

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Annealing of isotropic nylon-6,6

Babatope

Isaac

1992

Polymer

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The effect of annealing on the mechanism of plastic deformation of oriented polypropylene

Cited by 9 publications

References 13 publications

Ordering Effects and Percolation in the Structure Formation Process of the Oriented Polyolefin Porous Films

Ordering Effects and Percolation in the Structure Formation Process of the Oriented Polyolefin Porous Films

Optomechanical variations in cold‐drawn thermally treated polypropylene fibers

Annealing of isotropic nylon-6,6

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