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.

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.

scholarly journals Bio-Copolyesters of Poly(butylene succinate)(PBS) Containing Long Chain Bio-Based Glycol

2019 ◽  
Author(s):  
Karolina Stępień ◽  
Cathrine Miles ◽  
Andrew McClain ◽  
Ewa Wiśniewska ◽  
Peter Sobolewski ◽  
...  
Keyword(s):  
Linear Trend ◽  
Melt Flow Index ◽  
Pilot Scale ◽  
Elastic Behavior ◽  
Flow Index ◽  
Melt Flow ◽  
Scanning Calorimetry ◽  
Butylene Succinate ◽  
Weight Density ◽  
Long Chain

<p>Poly(butylene succinate) (PBS) is a thermoplastic and biodegradable polyester characterized by high rigidity due to its high crystallinity. However, the use of long chain biobased monomers to produce segmented copolymers is an effective strategy to tailor the properties of PBS, such as greater flexibility. In this paper, a series of aliphatic bio-copolyesters of poly(butylene succinate-dilinoleic succinate) (PBS-DLS) were successfully synthesized <i>via </i>a direct two-step polycondensation method using a semi-pilot scale reactor for melt polymerization and titanium dioxide/silicon dioxide coprecipitate catalyst (C-94). In this study, the thermal and mechanical properties were investigated and compared, focusing on the effect of varying the amount of biobased dilinoleic diol in the structure. With increasing amount of long chain diol, a decrease in molecular weight, density, and melt flow index was observed. The semicrystalline nature of the copolymers was confirmed using differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA) methods. These copolymers exhibit two main transition temperatures and vary in softness and processing flexibility. Furthermore, in the DSC data a linear trend was observed with increasing wt.% of hard PBS segments, which can be described by the Gordon-Taylor equation. Increasing the soft DLS segment content in the copolymer series resulted in an increase in the elastic behavior of the polymers. The broad range of crystallization temperatures and melt flow index values indicates that a polyester library with customizable properties that spans PBS applications has been successfully obtained.</p>

Bio-Copolyesters of Poly(butylene succinate)(PBS) Containing Long Chain Bio-Based Glycol

2019 ◽  
Author(s):  
Karolina Stępień ◽  
Cathrine Miles ◽  
Andrew McClain ◽  
Ewa Wiśniewska ◽  
Peter Sobolewski ◽  
...  
Keyword(s):  
Linear Trend ◽  
Melt Flow Index ◽  
Pilot Scale ◽  
Elastic Behavior ◽  
Flow Index ◽  
Melt Flow ◽  
Scanning Calorimetry ◽  
Butylene Succinate ◽  
Weight Density ◽  
Long Chain

<p>Poly(butylene succinate) (PBS) is a thermoplastic and biodegradable polyester characterized by high rigidity due to its high crystallinity. However, the use of long chain biobased monomers to produce segmented copolymers is an effective strategy to tailor the properties of PBS, such as greater flexibility. In this paper, a series of aliphatic bio-copolyesters of poly(butylene succinate-dilinoleic succinate) (PBS-DLS) were successfully synthesized <i>via </i>a direct two-step polycondensation method using a semi-pilot scale reactor for melt polymerization and titanium dioxide/silicon dioxide coprecipitate catalyst (C-94). In this study, the thermal and mechanical properties were investigated and compared, focusing on the effect of varying the amount of biobased dilinoleic diol in the structure. With increasing amount of long chain diol, a decrease in molecular weight, density, and melt flow index was observed. The semicrystalline nature of the copolymers was confirmed using differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA) methods. These copolymers exhibit two main transition temperatures and vary in softness and processing flexibility. Furthermore, in the DSC data a linear trend was observed with increasing wt.% of hard PBS segments, which can be described by the Gordon-Taylor equation. Increasing the soft DLS segment content in the copolymer series resulted in an increase in the elastic behavior of the polymers. The broad range of crystallization temperatures and melt flow index values indicates that a polyester library with customizable properties that spans PBS applications has been successfully obtained.</p>

scholarly journals Bio-Copolyesters of Poly(butylene succinate)(PBS) Containing Long Chain Bio-Based Glycol

2019 ◽  
Author(s):  
Karolina Stępień ◽  
Cathrine Miles ◽  
Andrew McClain ◽  
Ewa Wiśniewska ◽  
Peter Sobolewski ◽  
...  
Keyword(s):  
Linear Trend ◽  
Melt Flow Index ◽  
Pilot Scale ◽  
Elastic Behavior ◽  
Flow Index ◽  
Melt Flow ◽  
Scanning Calorimetry ◽  
Butylene Succinate ◽  
Weight Density ◽  
Long Chain

<p>Poly(butylene succinate) (PBS) is a thermoplastic and biodegradable polyester characterized by high rigidity due to its high crystallinity. However, the use of long chain biobased monomers to produce segmented copolymers is an effective strategy to tailor the properties of PBS, such as greater flexibility. In this paper, a series of aliphatic bio-copolyesters of poly(butylene succinate-dilinoleic succinate) (PBS-DLS) were successfully synthesized <i>via</i>a direct two-step polycondensation method using a semi-pilot scale reactor for melt polymerization and titanium dioxide/silicon dioxide coprecipitate catalyst (C-94). In this study, the thermal and mechanical properties were investigated and compared, focusing on the effect of varying the amount of biobased dilinoleic diol in the structure. With increasing amount of long chain diol, an increase in molecular weight, density, and melt flow index was observed. The semicrystalline nature of the copolymers was confirmed using differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA) methods. These copolymers exhibit two main transition temperatures and vary in softness and processing flexibility. Furthermore, in the DSC data a linear trend was observed with increasing wt.% of hard PBS segments, which can be described by the Gordon-Taylor equation. Increasing the soft DLS segment content in the copolymer series resulted in an increase in the elastic behavior of the polymers. The broad range of crystallization temperatures and melt flow index values indicates that a polyester library with customizable properties that spans PBS applications has been successfully obtained.</p>

scholarly journals Enhancement of mechanical, thermal and water uptake performance of TPU/jute fiber green composites via chemical treatments on fiber surface

e-Polymers ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 133-143 ◽  
Author(s):  
Tuffaha Fathe Salem ◽  
Seha Tirkes ◽  
Alinda Oyku Akar ◽  
Umit Tayfun
Keyword(s):  
Water Absorption ◽  
Water Uptake ◽  
Mechanical Test ◽  
Fiber Surface ◽  
Melt Flow Index ◽  
Jute Fiber ◽  
Morphological Properties ◽  
Flow Index ◽  
Melt Flow ◽  
Treatment Type

AbstractChopped jute fiber (JF) surfaces were modified using alkaline, silane and eco-grade epoxy resin. Surface characteristics of jute fibers were confirmed by FTIR and EDX analyses. JF filled polyurethane elastomer (TPU) composites were prepared via extrusion process. The effect of surface modifications of JF on mechanical, thermo-mechanical, melt-flow, water uptake and morphological properties of TPU-based eco-composites were investigated by tensile and hardness tests, dynamic mechanical analysis (DMA), melt flow index (MFI) test, water absorption measurements and scanning electron microscopy (SEM) techniques, respectively. Mechanical test results showed that silane and epoxy treated JF additions led to increase in tensile strength, modulus and hardness of TPU. Glass transition temperature (Tg) of TPU rose up to higher values after JF inclusions regardless of treatment type. Si-JF filled TPU exhibited the lowest water absorption among composites. Surface treated JFs displayed homogeneous dispersion into TPU and their surface were covered by TPU according to SEM micro-photographs.

Rheological Study on of PBT with High Melt Flow Index

2012 ◽  
Vol 487 ◽  
pp. 644-648
Author(s):  
Yuan Liu ◽  
Lin Wang ◽  
Qing Yan Xu ◽  
Pei Jie Lin ◽  
Zhi Hong Guo ◽  
...  
Keyword(s):  
Activation Energy ◽  
Shear Rate ◽  
Apparent Viscosity ◽  
Melt Flow Index ◽  
Flow Index ◽  
Melt Flow ◽  
Flow Activation Energy ◽  
Nonwoven Fabrics ◽  
Flow Activation ◽  
High Flexibility

Melt-blown generated PBT nonwoven fabrics usually have small fibril diameter, high flexibility, well heat and oil resistance. Therefore, they would have promising application such as vehicle filtering media. The rheological behavior of PBT with High Melt Flow Index for Melt-blown is investigated in this paper. It is a direction of the technology design and fabrication parameters .The relation of apparent viscosity and shear rate is analyzed, as well as flow activation energy and Non-Newtonian indexes. The results suggest that PBT with High Melt Flow Index is Non-Newtonian fluid. Apparent viscosity and flow activation energy show gradually decrease with increasing shear rate, exhibiting typical shear-thinning behavior.

From melt flow index to rheogram

1983 ◽  
Vol 22 (1) ◽  
pp. 90-101 ◽  
Author(s):  
A. V. Shenoy ◽  
S. Chattopadhyay ◽  
V. M. Nadkarni
Keyword(s):  
Melt Flow Index ◽  
Flow Index ◽  
Melt Flow

Thermomechanical investigations of PEKK-HAp-CS composites

2019 ◽  
Vol 233 (11) ◽  
pp. 1196-1203
Author(s):  
Rupinder Singh ◽  
Gurchetan Singh ◽  
Jaskaran Singh ◽  
Ranvijay Kumar ◽  
Md Mustafizur Rahman ◽  
...  
Keyword(s):  
Melt Flow Index ◽  
Extrusion Process ◽  
Flow Index ◽  
Fused Deposition Modelling ◽  
Index Test ◽  
Melt Flow ◽  
Scanning Calorimetry ◽  
Fused Deposition ◽  
Ether Ketone ◽  
Input Variables

In this experimental study, a composite of poly-ether-ketone-ketone by reinforcement of hydroxyapatite and chitosan has been prepared for possible applications as orthopaedic scaffolds. Initially, different weight percentages of hydroxyapatite and chitosan were reinforced in the poly-ether-ketone-ketone matrix and tested for melt flow index in order to check the flowability of different compositions/proportions. Suitable compositions revealed by the melt flow index test were then taken forward for the extrusion of filament required for fused deposition modelling. For thermomechanical investigations, Taguchi-based design of experiments has been used with input variables in the extrusion process as follows: temperature, load applied and different composition/proportions. The specimens in the form of feedstock filament produced by the extrusion process were made to undergo tensile testing. The specimens were also inspected by differential scanning calorimetry and photomicrographs. Finally, the specimen showing the best performance from the thermomechanical viewpoint has been selected to extrude the filament for the fused deposition modelling process.

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