Molecular models for creep in oriented polyethylene fibers

2020 ◽  
Vol 153 (14) ◽  
pp. 144904
Author(s):  
Thomas C. O’Connor ◽  
Mark O. Robbins
Keyword(s):  
Molecular Models ◽  
Oriented Polyethylene ◽  
Polyethylene Fibers

Study On Polyethylene-Based Carbon Fibers Obtained by Sulfonation Under Hydrostatic Pressure

2021 ◽  
Author(s):  
Jong Hyun Eun ◽  
Joon Seok Lee
Keyword(s):  
Hydrostatic Pressure ◽  
Carbon Fibers ◽  
Tensile Modulus ◽  
Melt Flow Index ◽  
Elastic Behavior ◽  
Flow Index ◽  
Plastic Behavior ◽  
Melt Flow ◽  
Oriented Polyethylene ◽  
Polyethylene Fibers

Abstract Carbon fibers were prepared using polyethylene fibers. The draw ratio of the polyethylene fibers and the sulfonation mechanism were investigated under hydrostatic pressures of 1 and 5 bar. The influence of the melt flow index of polyethylene on the sulfonation reaction was studied. Carbon fibers were prepared through the sulfonation of linear low-density polyethylene (LLDPE) fibers possessing side chains with a high melt flow index. The polyethylene fibers, which exhibited thermoplastic properties and plastic behavior, were cross-linked through the sulfonation process. Their thermal properties and mechanical properties changed to thermoset properties and elastic behavior. Although sulfonation was performed under a hydrostatic pressure of 5 bar, it was difficult to convert the highly oriented polyethylene fibers because of their high crystallinity, but partially oriented polyethylene fibers could be converted to carbon fibers. Therefore, sulfonation was performed using partially oriented LLDPE fibers with a melt flow index of 20 at 130°C for 2.5 hours under a hydrostatic pressure of 5 bar. The resulting fibers were carbonized under the following conditions: 1000°C, 5°C/min, and five minutes. Carbon fibers with a tensile strength of 2.03 GPa, a tensile modulus of 143.63 GPa, and an elongation at break of 1.42% were prepared.

Organoplastics Based on Highly Oriented Polyethylene Fibers

MICC 90 ◽  
1991 ◽  
pp. 740-745
Author(s):  
E. F. Kharchenko ◽  
V. D. Protassov ◽  
A. A. Kulkov ◽  
A. S. Chervyakov
Keyword(s):  
Oriented Polyethylene ◽  
Polyethylene Fibers

scholarly journals Study on polyethylene-based carbon fibers obtained by sulfonation under hydrostatic pressure

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jong Hyun Eun ◽  
Joon Seok Lee
Keyword(s):  
Hydrostatic Pressure ◽  
Carbon Fibers ◽  
Melt Flow Index ◽  
Elastic Behavior ◽  
Flow Index ◽  
Plastic Behavior ◽  
Melt Flow ◽  
Polyethylene Fiber ◽  
Oriented Polyethylene ◽  
Polyethylene Fibers

AbstractPolyethylene based carbon fibers were studied using high density polyethylene(HDPE) fibers and linear low density polyethylene(LLDPE) fibers with various melt flow index. The draw ratio of the polyethylene fibers and the sulfonation mechanism were investigated under hydrostatic pressures of 1 and 5 bar in the first time. The influence of the melt flow index of polyethylene and types of polyethylene fibers on the sulfonation reaction was studied. Carbon fibers were prepared through the sulfonation of LLDPE fibers possessing side chains with a high melt flow index. The polyethylene fibers, which exhibited thermoplastic properties and plastic behavior, were cross-linked through the sulfonation process. Their thermal properties and mechanical properties changed to thermoset properties and elastic behavior. Although sulfonation was performed under a hydrostatic pressure of 5 bar, it was difficult to convert the highly oriented polyethylene fibers because of their high crystallinity, but partially oriented polyethylene fibers could be converted to carbon fibers. Therefore, the effect of fiber orientation on fiber crosslinking, which has not been reported in previous literature, has been studied in detail, and a new method of hydrostatic pressure sulfonation has been successful in thermally stabilizing polyethylene fiber. Hydrostatic sulfonation was performed using partially oriented LLDPE fibers with a melt flow index of 20 at 130 °C for 2.5 h under a hydrostatic pressure of 5 bar. The resulting fibers were carbonized under the following conditions: 1000 °C, 5 °C/min, and five minutes. Carbon fibers with a tensile strength of 2.03 GPa, a tensile modulus of 143.63 GPa, and an elongation at break of 1.42% were prepared.

Structural Determination of the Hydrofullerene C60D36 by Neutron Diffraction

1998 ◽  
Vol 54 (3) ◽  
pp. 345-350 ◽  
Author(s):  
L. E. Hall ◽  
D. R. McKenzie ◽  
R. L. Davis ◽  
M. I. Attalla ◽  
A. M. Vassallo
Keyword(s):  
Neutron Diffraction ◽  
Density Function ◽  
Diffraction Data ◽  
Fourier Transformation ◽  
Structural Determination ◽  
Molecular Models ◽  
Reduced Density ◽  
C Nmr

A mixture of C60D36 with 24.5 \pm 4.5% C60 by weight has been analysed by neutron diffraction techniques. The diffraction data was converted to a reduced density function G(r) by Fourier transformation. The C60 component of the G(r) was subtracted out. This enabled a comparison for five molecular models of C60D36, with symmetries T, Th , S 6 and two D 3 d isomers, with the experimental G(r). This specimen of C60D36 was found to be best described by a T symmetry isomer, in agreement with 13C NMR and IR data for C60H36 [Attalla et al. (1993). J. Phys. Chem. pp. 6329–6331].

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