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.

scholarly journals Progress in Research on Carbon Nanotubes Reinforced Cementitious Composites

2015 ◽  
Vol 2015 ◽  
pp. 1-16 ◽  
Author(s):  
Qinghua Li ◽  
Jintao Liu ◽  
Shilang Xu
Keyword(s):  
Carbon Nanotubes ◽  
Large Scale ◽  
High Strength ◽  
Cementitious Composites ◽  
Scale Production ◽  
Multiwalled Carbon ◽  
Factors Affecting ◽  
Environment And Health ◽  
Research Activities ◽  
Major Factors

As one-dimensional (1D) nanofiber, carbon nanotubes (CNTs) have been widely used to improve the performance of nanocomposites due to their high strength, small dimensions, and remarkable physical properties. Progress in the field of CNTs presents a potential opportunity to enhance cementitious composites at the nanoscale. In this review, current research activities and key advances on multiwalled carbon nanotubes (MWCNTs) reinforced cementitious composites are summarized, including the effect of MWCNTs on modulus of elasticity, porosity, fracture, and mechanical and microstructure properties of cement-based composites. The issues about the improvement mechanisms, MWCNTs dispersion methods, and the major factors affecting the mechanical properties of composites are discussed. In addition, large-scale production methods of MWCNTs and the effects of CNTs on environment and health are also summarized.

scholarly journals Determination of the Structural Integrity and Stability of Polysialic Acid during Alkaline and Thermal Treatment

Molecules ◽  
2019 ◽  
Vol 25 (1) ◽  
pp. 165
Author(s):  
Bastian Bartling ◽  
Johanna S. Rehfeld ◽  
Daniel Boßmann ◽  
Ingo de Vries ◽  
Jörg Fohrer ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Large Scale ◽  
Polysialic Acid ◽  
Alkaline Solutions ◽  
Low Molecular Weight ◽  
Outer Cell ◽  
Scale Production ◽  
Thermal Hydrolysis ◽  
E Coli ◽  
Chain Lengths

Polysialic acid (polySia) is a linear homopolymer of varying chain lengths that exists mostly on the outer cell membrane surface of certain bacteria, such as Escherichia coli (E. coli) K1. PolySia, with an average degree of polymerization of 20 (polySia avDP20), possesses material properties that can be used for therapeutic applications to treat inflammatory neurodegenerative diseases. The fermentation of E. coli K1 enables the large-scale production of endogenous long-chain polySia (DP ≈ 130) (LC polySia), from which polySia avDP20 can be manufactured using thermal hydrolysis. To ensure adequate biopharmaceutical quality of the product, the removal of byproducts and contaminants, such as endotoxins, is essential. Recent studies have revealed that the long-term incubation in alkaline sodium hydroxide (NaOH) solutions reduces the endotoxin content down to 3 EU (endotoxin units) per mg, which is in the range of pharmaceutical applications. In this study, we analyzed interferences in the intramolecular structure of polySia caused by harsh NaOH treatment or thermal hydrolysis. Nuclear magnetic resonance (NMR) spectroscopy revealed that neither the incubation in an alkaline solution nor the thermal hydrolysis induced any chemical modification. In addition, HPLC analysis with a preceding 1,2-diamino-4,5-methylenedioxybenzene (DMB) derivatization demonstrated that the alkaline treatment did not induce any hydrolytic effects to reduce the maximum polymer length and that the controlled thermal hydrolysis reduced the maximum chain length effectively, while cost-effective incubation in alkaline solutions had no adverse effects on LC polySia. Therefore, both methods guarantee the production of high-purity, low-molecular-weight polySia without alterations in the structure, which is a prerequisite for the submission of a marketing authorization application as a medicinal product. However, a specific synthesis of low-molecular-weight polySia with defined chain lengths is only possible to a limited extent.

In vitro synthesis of glycogen: the structure, properties, and physiological function of enzymatically-synthesized glycogen

Biologia ◽  
2011 ◽  
Vol 66 (3) ◽  
Author(s):  
Hideki Kajiura ◽  
Hiroki Takata ◽  
Tsunehisa Akiyama ◽  
Ryo Kakutani ◽  
Takashi Furuyashiki ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Chain Length ◽  
Large Scale ◽  
Glycogen Synthesis ◽  
Average Molecular Weight ◽  
Spherical Particles ◽  
Average Chain Length ◽  
Scale Production ◽  
In Vitro Synthesis

AbstractThis review describes a new enzymatic method for in vitro glycogen synthesis and its structure and properties. In this method, short-chain amylose is used as the substrate for branching enzymes (BE, EC 2.4.1.18). Although a kidney bean BE and Bacillus cereus BE could not synthesize high-molecular weight glucan, BEs from 6 other bacterial sources produced enzymatically synthesized glycogen (ESG). The BE from Aquifex aeolicus was the most suitable for the production of glycogen with a weight-average molecular weight (M w) of 3,000–30,000 k. The molecular weight of the ESG is controllable by changing the concentration of the substrate amylose. Furthermore, the addition of amylomaltase (AM, EC 2.4.1.25) significantly enhanced the efficiency of this process, and the yield of ESG reached approximately 65%. Typical preparations of ESG obtained by this method were subjected to structural analyses. The average chain length, interior chain length, and exterior chain length of the ESGs were 8.2–11.6, 2.0–3.3, and 4.2–7.6, respectively. Transmission electron microscopy and intrinsic viscosity measurement showed that the ESG molecules formed spherical particles. Unlike starch, the ESGs were barely degraded by pullulanase. Solutions of ESG were opalescent (milky-white and slightly bluish), and gave a reddishbrown color on the addition of iodine. These analyses revealed that ESG shares similar molecular shapes and solution properties with natural-source glycogen. Moreover, ESG had macrophage-stimulating activity and its activity depends on the molecular weight of ESG. We successfully achieved large scale production of ESG. ESG could lead to new industrial applications, such as in the food, chemical, and pharmaceutical fields.

scholarly journals A general aerosol-assisted biosynthesis of functional bulk nanocomposites

2018 ◽  
Vol 6 (1) ◽  
pp. 64-73 ◽  
Author(s):  
Qing-Fang Guan ◽  
Zi-Meng Han ◽  
Tong-Tong Luo ◽  
Huai-Bin Yang ◽  
Hai-Wei Liang ◽  
...  
Keyword(s):  
Electromagnetic Interference ◽  
Large Scale ◽  
Bulk Material ◽  
Cellulose Nanofibrils ◽  
High Strength ◽  
Building Blocks ◽  
Scale Production ◽  
Cellulose Nanofibril ◽  
Practical Applications ◽  
Wide Range

Abstract Although a variety of nanoparticles with better-than-bulk material performances can be synthesized, it remains a challenge to scale the extraordinary properties of individual nanoscale units to the macroscopic level for bulk nanostructured materials. Here, we report a general and scalable biosynthesis strategy that involves simultaneous growth of cellulose nanofibrils through microbial fermentation and co-deposition of various kinds of nanoscale building blocks (NBBs) through aerosol feeding on solid culture substrates. We employ this biosynthesis strategy to assemble a wide range of NBBs into cellulose nanofibril-based bulk nanocomposites. In particular, the biosynthesized carbon nanotubes/bacterial cellulose nanocomposites that consist of integrated 3D cellulose nanofibril networks simultaneously achieve an extremely high mechanical strength and electrical conductivity, and thus exhibit outstanding performance as high-strength lightweight electromagnetic interference shielding materials. The biosynthesis approach represents a general and efficient strategy for large-scale production of functional bulk nanocomposites with enhanced performances for practical applications. Industrial-scale production of these bulk nanocomposite materials for practical applications can be expected in the near future.

Preparation and Characterization of MWCNT/Ultrahigh-Molecular-Weight Polyethylene Composite Fiber

2012 ◽  
Vol 627 ◽  
pp. 761-764
Author(s):  
Tao Zhang ◽  
Tian Ma ◽  
Jian Chun Zhang ◽  
Peng Gang Gao ◽  
Hua Zhang ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Precursor Solution ◽  
Ultrahigh Molecular Weight Polyethylene ◽  
Composite Fiber ◽  
Gel Spinning ◽  
Polyethylene Composite ◽  
Ultrahigh Molecular Weight ◽  
Aggregation Structure ◽  
Uhmwpe Fibers

MWCNT/Ultrahigh-molecular-weight polyethylene (MWCNT/UHMWPE) composite was prepared by adding purified MWCNTs into the precursor solution of UHMWPE. Based on that, MWCNT/UHMWPE fibers were obtained using a gel spinning-molding technique. The thermal, mechanical and aggregation structure of MWCNT/UHMWPE fibers were characterized by TGA, mechanical property measurement and XRD, respectively. The results indicated the incorporation of MWCNTs into UHMWPE macromolecular chains have not change the aggregation structure of UHMWPE significantly, and the as-prepared MWCNT/UHMWPE fibers have evidently improved thermal stability and mechanical strength compared with the pristine UHMWPE fibers.

Twist-film gel spinning of large-diameter high-performance ultra-high molecular weight polyethylene monofilaments

2016 ◽  
Vol 87 (19) ◽  
pp. 2323-2336 ◽  
Author(s):  
Xudong Fang ◽  
Jing Shi ◽  
Tom Wyatt ◽  
Donggang Yao
Keyword(s):  
Molecular Weight ◽  
Solvent Extraction ◽  
High Molecular Weight ◽  
High Performance ◽  
Large Diameter ◽  
High Strength ◽  
Gel Spinning ◽  
Solvent Removal ◽  
Spinning Process ◽  
Ultra High Molecular Weight

A twist-film gel spinning process was developed for large-diameter high-performance ultra-high molecular weight polyethylene (UHMWPE) monofilaments. By using polybutene as a spin-solvent, film twisting was demonstrated to be an effective method for solvent removal; approximately 70% of solvent contained in the gel film can be removed simply by film twisting. This mechanical solvent removal process also makes conventional solvent extraction proceed significantly faster. Besides improved solvent extraction efficiency, large-diameter high-strength UHMWPE monofilaments (with diameters of about 80 µm and strength exceeding 3.2 GPa) can be produced with this process, which is difficult to achieve using conventional processes. The capability of making large-diameter high-strength monofilaments may allow new products of UHMWPE to be developed in a number of high-performance applications.

scholarly journals TURBIDIMETRIC DETERMINATION OF THE TURBIDITY INDEX OF SPENT PARAFFIN OIL

2020 ◽  
pp. 107-112
Author(s):  
Александр Викторович Соколов ◽  
Роман Владиславович Королёв ◽  
Светлана Дмитриевна Хижняк ◽  
Татьяна Ивановна Самсонова ◽  
Владимир Петрович Галицын ◽  
...  
Keyword(s):  
High Strength ◽  
Gel Spinning ◽  
Turbidimetric Method ◽  
Paraffin Oil

Проведены исследования по определению показателя мутности отработанного вазелинового (парафинового) масла, используемого в качестве растворителя при получении высокопрочных волокон из сверхвысокомолекулярного полиэтилена (СВМПЭ) методом гель-формования, турбидиметрическим методом по стандартным формазиновым растворам. Доказана возможность применения данного метода для оценки показателя мутности отработанного растворителя. The results of research on determining the turbidity index of spent Vaseline (paraffin) oil used as a solvent for the production of high-strength fibers from ultrahigh-molecular polyethylene (UHMWPE) by gel-spinning, turbidimetric method for standard formazine solutions are presented. The possibility of using this method to estimate the turbidity index of the spent solvent is proved.

Influence of technological parameters on the upholstery seams in furniture

2021 ◽  
Vol 114 ◽  
pp. 110-115
Author(s):  
Ewa Skorupińska ◽  
Krzysztof Wiaderek ◽  
Maciej Sydor
Keyword(s):  
Large Scale ◽  
High Strength ◽  
Real Problem ◽  
Scale Production ◽  
Test Results ◽  
Technological Parameters ◽  
Elongation At Break ◽  
Large Scale Production ◽  
Long Duration ◽  
Wooden Furniture

Influence of technological parameters of the upholstery seams in furniture. Based on the real problem of weak seams in covers of wooden furniture, a multifaceted analysis of the issue was performed. As a result, it was decided to carry out comparative laboratory strength tests of seams made with the use of various technological parameters. For the production of test samples, we used different yarn threads to find the best and sufficiently strong seams for used fabrics. The test results show that not only the thread and fabric used, but also the sewing technology parameters have a significant influence on the seam strength. Overall, these results indicate that to increase the seam strength, it is necessary to choose thread type B with very high strength and low elongation at break. This solution will minimize the risk of broken threads in case of deviation of material features and technological parameters, which can be variable in the long duration of large-scale production.

The structure of high-strength ultrahigh-molecular-weight polyethylene fibres fabricated by the gel-spinning method

2006 ◽  
Vol 38 (3) ◽  
pp. 200-206 ◽  
Author(s):  
P. M. Pakhomov ◽  
A. Yu. Golikova ◽  
S. D. Khizhnyak ◽  
M. A. Shavyrina ◽  
V. P. Galitsin ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Strength ◽  
Ultrahigh Molecular Weight Polyethylene ◽  
Gel Spinning ◽  
Ultrahigh Molecular Weight

scholarly journals Особенности статистических распределений прочностей моно- и полифиламентных ультраориентированных высокопрочных волокон сверхвысокомолекулярного полиэтилена

2020 ◽  
Vol 62 (4) ◽  
pp. 590
Author(s):  
Ю.М. Бойко ◽  
В.А. Марихин ◽  
О.А. Москалюк ◽  
Л.П. Мясникова
Keyword(s):  
Molecular Weight ◽  
Tensile Strength ◽  
Distribution Function ◽  
Draw Ratio ◽  
High Strength ◽  
Strength Distribution ◽  
Statistical Distributions ◽  
Gaussian Models ◽  
Uhmwpe Fibers ◽  
Ultra High Molecular Weight

The patterns of the statistical distributions of tensile strength of high-strength ultraoriented mono-and multifilament fibers, consisting of several hundred single fibers of ultra-high-molecular-weight polyethylene (UHMWPE), have been analyzed using the Weibull and Gaussian models by considering a large number of measurements (50 identical samples in each series). It has been shown that the strength distribution of the multifilament UHMWPE fibers can be described both within the normal Gaussian distribution and the standard Weibull distribution function. At the same time, the strength distribution of the UHMWPE monofilaments oriented to a final draw ratio of 120 is not subject to the normal distribution. The reasons for the revealed differences in the types of the statistical strength distributions of the mono- and multifilaments of high-strength UHMWPE during fracture are discussed.

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