Molecular Weight Discrete Distribution-Induced Orientation of High-Strength Copolyamide Fibers: Effects of Component Proportion and Molecular Weight

2021 ◽  
Author(s):  
Jialiang Zhou ◽  
Qianqian Wang ◽  
Chao Jia ◽  
Mugaanire Tendo Innocent ◽  
Weinan Pan ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Discrete Distribution ◽  
High Strength

scholarly journals The nanostructuring of ultra-high-molecular-weight polyethylene in thermal and mechanical fields as revealed by DSC

2021 ◽  
Vol 2103 (1) ◽  
pp. 012095
Author(s):  
L P Myasnikova ◽  
A K Borisov ◽  
Yu M Boiko ◽  
A P Borsenko ◽  
V F Drobot’ko ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Melting Temperature ◽  
Mechanical Characteristics ◽  
Thickness Distribution ◽  
High Strength ◽  
High Modulus ◽  
Know How ◽  
First Time ◽  
Ultra High Molecular Weight

Abstract The ultra-high-molecular-weight polyethylene reactor powders are widely used for the actively developing solvent-free method for producing high-strength high-modulus PE filaments, which includes the compaction and sintering of a powder followed by orientational hardening. To find an appropriate regime of the technological process, it is important to know how the nanostructure changes when transforming from a powder to a precursor for hardening. Nanocrystalline lamellae are characteristics of the powder structure. For the first time, the DSC technique was used to follow changes in the thickness distribution of lamellae in ultra-high-molecular-weight polyethylene reactor powder on its way to a precursor for orientation hardening. It was found that the percentage of thick (>15 nm) and thin (10 nm) lamellae in compacted samples and those sintered at temperatures lower than the melting temperature of PE (140°C) remains nearly the same. However, significant changes in the content of lamellae of different thicknesses were observed in the samples sintered at 145°C with subsequent cooling under different conditions. The influence of the lamellae thickness distribution in precursors on the mechanical characteristics of oriented filaments was discussed.

scholarly journals Unprecedented High-Modulus High-Strength Tapes and Films of Ultrahigh Molecular Weight Polyethylene via Solvent-Free Route

2011 ◽  
Vol 44 (14) ◽  
pp. 5558-5568 ◽  
Author(s):  
Sanjay Rastogi ◽  
Yefeng Yao ◽  
Sara Ronca ◽  
Johan Bos ◽  
Joris van der Eem
Keyword(s):  
Molecular Weight ◽  
High Strength ◽  
Ultrahigh Molecular Weight Polyethylene ◽  
Solvent Free ◽  
High Modulus ◽  
Ultrahigh Molecular Weight

The radiation effect on thermal conductivity of high strength ultra-high-molecular-weight polyethylene fiber by γ-rays

2006 ◽  
Vol 101 (4) ◽  
pp. 2619-2626 ◽  
Author(s):  
Atsuhiko Yamanaka ◽  
Yoshinobu Izumi ◽  
Tooru Kitagawa ◽  
Takaya Terada ◽  
Hideki Sugihara ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Molecular Weight ◽  
High Molecular Weight ◽  
Radiation Effect ◽  
High Strength ◽  
Polyethylene Fiber ◽  
Γ Rays ◽  
Ultra High Molecular Weight

Effect of Molecular Weight and Concentration on Gel-Spun UHMWPE Fibers With Polybutene as a New Spin Solvent

2017 ◽  
Author(s):  
Xudong Fang ◽  
Weixuan Jing ◽  
Libo Zhao ◽  
Yulong Zhao ◽  
Zhuangde Jiang
Keyword(s):  
Molecular Weight ◽  
Large Scale ◽  
Extraction Efficiency ◽  
High Strength ◽  
Scale Production ◽  
Gel Spinning ◽  
Effective Spin ◽  
Paraffin Oil ◽  
Uhmwpe Fibers ◽  
Dope Concentration

Ultrahigh molecular weight polyethylene (UHMWPE) fibers have been investigated for years to improve performance with gel spinning process for wide applications in industry. Various spin solvents have been attempted including paraffin oil, decahydronaphthalene (decalin), kerosene etc. However, more work still needs to be done because of environmental issues or long extraction process of the aforementioned solvents. Recently, polybutene was found to be an effective spin solvent for UHMWPE fibers, which is environmentally friendly and widely available on the market. Besides producing high strength fibers, compared to paraffin oil, polybutene can form a gel with UHMWPE showing stronger phase separation behavior at room temperature. Because of this property, more extraction solvents can be saved. It was also demonstrated with experiments that the extraction efficiency is higher than that of the gel fiber formed with paraffin oil. Thus, polybutene has high potential to be used in large-scale production of UHMWPE fibers, which deserves further study. In this work, polybutene with different molecular weight was used to form spin dopes with UHMWPE. The dope concentration for each type of polybutene was also varied to check the effect of molecular weight and dope concentration on fiber properties. Viscoelastic properties of the spin dopes were obtained with parallel plate rheometry while thermodynamic properties of the dopes were characterized with differential scanning calorimetry (DSC) and thermal gravitational analysis (TGA). With optimized processing conditions, high strength fibers were collected and the crystalline structure was examined with wide angel X-ray diffraction (WAXD). DSC and TGA data also provided support for the effect of molecular weight and concentration of polybutene. It can be found that stronger fibers are obtained with lower concentration spin dopes. The viscosity of the dopes and corresponding spinning conditions are significantly affected by molecular weight of polybutene. Extraction efficiency is affected by both molecular weight and dope concentration. To obtain cost-effective superstrong UHMWPE fibers, an optimized design is needed based on the molecular weight of polybutene and the spin dope concentration.

Melt spinning of high-strength fiber from low-molecular-weight polypropylene

2015 ◽  
Vol 56 (2) ◽  
pp. 233-239 ◽  
Author(s):  
Qianchao Mao ◽  
Tom P. Wyatt ◽  
An-Ting Chien ◽  
Jinnan Chen ◽  
Donggang Yao
Keyword(s):  
Molecular Weight ◽  
Melt Spinning ◽  
High Strength ◽  
Low Molecular Weight ◽  
High Strength Fiber

Study of the relationship between characteristics of aramid fibrids and mechanical property of aramid paper using DSC

e-Polymers ◽  
2014 ◽  
Vol 14 (2) ◽  
pp. 139-144 ◽  
Author(s):  
Huifang Zhao ◽  
Yinbang Zhu ◽  
Lizheng Sha
Keyword(s):  
Molecular Weight ◽  
Thermal Properties ◽  
Mechanical Strength ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
High Strength ◽  
Scanning Calorimetry ◽  
The Relationship ◽  
Different Sources

AbstractFiber classification of aramid fibrids was carried out using a Bauer-McNett fiber classifier, and the molecular weight and thermal properties of different sizes of aramid fibrids were determined with viscometry and differential scanning calorimetry (DSC), respectively. Aramid handsheets were made from different sizes of aramid fibrids and aramid short fibers, and the relationship between mechanical strength of aramid handsheets and thermal properties of aramid fibrids was examined. In addition, aramid papers from four different sources were also investigated to elucidate the relationship between their thermal properties and mechanical strength. It was found that aramid fibrids passing through 30-mesh screens and remaining on 50-mesh screens and aramid fibrids with narrower molecular weight distribution are suitable for the production of high-strength aramid papers. Lower crystallinity and wider molecular weight distribution are important contributors to the lower mechanical strength of domestic aramid paper when compared to that of Nomex paper.

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