Drawing Behavior of Ultrahigh Molecular Weight Polyethylene (UHMWPE) Fibers in Supercritical CO2

2002 ◽  
Author(s):  
Alan J. Lesser
Keyword(s):  
Molecular Weight ◽  
Supercritical Co2 ◽  
Ultrahigh Molecular Weight Polyethylene ◽  
Ultrahigh Molecular Weight ◽  
Uhmwpe Fibers

Analysis of plasma effect on ultrahigh-molecular weight polyethylene fibers’ surface energy on strength of fibers and fiber reinforced composites

2021 ◽  
Vol 3 ◽  
pp. 42-54
Author(s):  
V. I. Mamonov ◽  
Keyword(s):  
Crystal Structure ◽  
Molecular Weight ◽  
Surface Energy ◽  
Ultrahigh Molecular Weight Polyethylene ◽  
Necessary Condition ◽  
Matrix System ◽  
Maximal Load ◽  
Ultrahigh Molecular Weight ◽  
Uhmwpe Fibers ◽  
Fiber Matrix

Completely saturated chemical bonds in ultrahigh-molecular-weight polyethylene (UHMWPE) fibers — are a reason for their low surface energy (FSE), i.e. inert properties. Elongated crystal structure of UHMWPE molecules ensures high anisotropic tensile strength of the fibers. An inertness is a problem for utilization these fibers in high-strength composites production. Surface energy (SE) difference of the fibers and a binder in fiber/matrix system hinders chemical interaction at interphase boundary and worsens fiber wettability. Increase in their FSE is a topical task for this problem decision. Necessary condition of FSE increase is the integrity of molecule structure, lying under modified surface. Low temperature, nonequilibrium plasma (LTP) treatment in a medium of argon and argon/propane mixture, used in this work for plasma activation of fibers’ surface, permits to abide by this condition. However, plasma ion bombardment during a process of activation can modify interior crystal structure and, as a result, decrease their strength. The rovings SK75 (Holland) and D800 (China) were used for study of the properties of UHMWPE fibers after plasma treatment. Activation effect on FSE, strength, and fibers’ wetting by water and epoxy binder before and after ageing was studied. Capillary wetting of the fibers by distilled water used for FSE evaluation. The data of filaments surface structure and their diameter change at maximal load, obtained by optical microscope study, were used for the analysis of FSE and epoxy matrix effect on the strength of fiber/matrix systems. Essential distinction of SK75 and D800 fibers properties is ascertained. Negative effect of fibers’ and matrix’s stiffness, as well as increased FSE of stiff fibers on the strength of fiber/matrix system is revealed.

On the mechanical and morphological properties of highly performant composite laminates based on epoxy resin and oxidized ultrahigh-molecular-weight polyethylene fibers

2020 ◽  
Vol 32 (9) ◽  
pp. 992-1000 ◽  
Author(s):  
Raouf Belgacemi ◽  
Mehdi Derradji ◽  
Abdelrazak Mouloud ◽  
Djalal Trache ◽  
Abdeldjalil Zegaoui ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Epoxy Resin ◽  
Composite Laminates ◽  
High Performance ◽  
Ultrahigh Molecular Weight Polyethylene ◽  
Cost Effective ◽  
Polymeric Matrix ◽  
Morphological Properties ◽  
Ultrahigh Molecular Weight ◽  
Uhmwpe Fibers

In this study, new high-performance composite laminates were prepared from epoxy resin and surface modified ultrahigh-molecular-weight polyethylene (UHMWPE) fibers. The UHMWPE fibers underwent two types of chemical modifications, namely through chromic acid and potassium permanganate oxidations. The adopted chemical procedure aimed the grafting of polar groups on the outer surface of fibers for an improved chemical and physical compatibility with the polymeric matrix. The efficiency of the grafting methodology was confirmed by vibrational, thermal, and morphological analyses, and the grafting mechanism was thoroughly discussed. Furthermore, composite laminates were prepared to study the effects of chemical treatments on the mechanical and morphological properties of the resulting composites. The grafting techniques allowed consequent improvements in the tensile and bending properties, up to 34% and 23% for the tensile and flexural strengths, respectively. The study of the fractured surfaces confirmed the exceptional compatibility between the fillers and the polymeric matrix and further corroborated the mechanical findings. Finally, the adopted modification techniques can be regarded as cost-effective and highly suitable for the manufacturing of structural composites for advanced applications.

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.

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